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Hyalella minuana Talhaferro & Bueno, n. sp. (Figs 3���8) Type locality: S��o Jos�� do Norte municipality, Rio Grande do Sul state, Brazil, sampling site P1 (31�� 62��� 68.96��� S, 51�� 42��� 59.12��� W). Type specimens. Holotype: male, body length = 7.0 mm; head length = 1.0 mm (MZUSP 41786), S��o Jos�� do Norte municipality (31�� 62��� 68.96��� S, 51�� 42��� 59.12��� W), September 2015, Pires, M. M. & cols. Allotype: female, body length = 5.2 mm, head length = 0.6 mm (MZUSP 41787), same locality as holotype. Paratypes: MZUSP 41788, 10 whole specimens (5 males and 5 females); CCUFLA 440, 10 whole specimens (5 males and 5 females), 3 males and 1 female on slides; CRU0012, 249 whole specimens (31 males, 110 females and 108 juveniles), and 2 males on slides (same collection data of the holotype); Additional specimens. CRU0013, 27 whole individuals (1 male, 9 females and 17 juveniles) and 5 males on slides, S��o Jos�� do Norte municipality, Rio Grande do Sul state, Brazil, sampling site P2 (31�� 51��� 10.17��� S, 51�� 26��� 73.47��� W), September 2015, Pires, M. M. & cols. Diagnosis. Body surface smooth. Eyes ovoid and pigmented. Antenna 1 shorter than antenna 2. Maxilla 1 with palp uniarticulate, not reaching half of the distance between the base of palp and base of the setae of the outer plate. Inner plate of maxilla 2 with two papposerrate setae. Propodus of gnathopod 1 hammer-shaped, longer than wide with nine serrate setae on inner margin. Peduncle of uropod 1 slightly longer than the ramus with seven cuspidate setae on margin, presence of curved seta (male) on inner ramus, followed by three cuspidate setae with decreasing size lined up a row. Peduncle of the uropod 2 slightly longer than the ramus, outer ramus with five cuspidate setae and inner ramus with six cuspidate setae, in both ramus there are is two robust cuspidate setae on apex (one long and one smaller). Peduncle of the uropod 3 and ramus with similar size, peduncle with three cuspidate setae and ramus with six simple setae and one robust cuspidate seta. Sternal gills on pereonites 2 to 7. Description of male. Mean body length: 7.78 �� 0.37 mm (n=5), mean head length = 0.96 �� 0.04 mm (n=5). Body surface smooth. Eyes ovoid and pigmented. Epimeral plate not acuminated (Fig. 3A). Antenna 1 (Fig. 3B): 3.4 mm; peduncle with three articles; first article longer than wide and longer than the third, first article with cuspidate setae on the distal margin; second article with simple setae distributed along the margin; flagellum with 13 articles, all with a group of 2-5 simple setae apically. Aesthetascs observed only in articles 2 and 11. Antenna 2 (Fig. 3C): 5.0 mm, surpassing half of the body length; peduncle longer than head length; flagellum consisting of 15 articles of similar size, with a group of 2-5 simple setae apically. Basic amphipodan mandible type (in sensu of Watling 1993) with palp absent. Right mandible (Fig 3D) incisor process with five teeth and two pappose setae with a group of setules. Left mandible (Fig. 3E) incisor process and lacinia mobilis with five teeth; three pappose setae under the lacinia mobilis. In both mandibles, the molar process is cylindrical, large and triturative, with a group of setules on superior margin and presence of long pappose setae on inner margin. Upper lip (Fig. 3F) with rounded borders and the presence of simple setae and setules, ventral margin with many setules. Lower lip (Fig. 3G) bilobed, with distal margins ovoid, presence of simple setae and setules on inner and distal margins, outer margin smooth. Maxilla 1 (Fig. 3H) palp short and unarticulated, thin apically with one simple seta and setules in the borders, length not reaching half of the distance between the base of the palp and base of the setae on outer plate; inner plate slender, almost reaching the half the length of the outer plate with two apex papposerrate setae, inner and outer margin covered by setules; outer plate with nine serrate setae distributed apically. Maxilla 2 (Fig. 3I) inner and outer plate similar in length and wide; inner plate with simple and serrate setae on apex, inner margin with two papposerrate setae (inner seta short and slender, outer seta long and robust); outer plate with long simple and serrate setae on the apex. Maxilliped (Fig. 3J) plates with apex rounded; inner plate with three cuspidate setae in cone-shaped apical and small pappose setae; inner margin with seven pappose setae, outer margin smooth; outer plate slightly longer than inner plate, with inner margin and apex covered by long simple setae and outer margin smooth; palp with four articles, article 1 with simple setae (1-4) on distal inner margin; article 2 longer and wider than article 3, with inner margin covered by long simple setae; distal inner margin of the article 3 covered by long simple setae, distal outer margin with a group of 4-6 serrate setae and simple setae; dactyl smooth, apex with one long and robust serrate setae and four simple setae subapical with half the length. Gnathopod 1 (Figs 4A, B) subchelate; base long with one simple seta on posterior margin; ischium and merus with a group of simple setae on disto-posterior margin; carpus longer than wide and longer than propodus, posterior lobe is long and convex, forming a shell-shaped structure with a margin covered by serrate setae, inner surface with six simple setae, and disto-anterior margin with a cluster of 5-7 serrate setae; propodus longer than wide, width about 1/5 shorter than length, hammer-shaped, inner face with nine serrate setae arranged in two rows and few smaller simple setae, anterior margin with one simple seta, disto-anterior border covered by comb-scales and a cluster of simple setae, disto-posterior border covered by comb-scales and margin with two simple setae; outer face of propodus not observed; palm transverse and covered by simple and smaller cuspidate setae with accessory seta, with three long and slender simple setae, disto-posterior border of the palm with one cuspidate setae with accessory seta, palm length 1/2 shorter than posterior margin of propodus; dactyl claw-like and covered by comb-scales, length not exceeding the margin of the palm, with one small plumose setae in outer margin. Gnathopod 2 (Figs 4C, D) subchelate; base long with five long simple setae on margin; ischium and merus with long simple setae on disto-posterior margin; carpus with distal margin slightly quadrate, posterior lobe of the carpus longer than wide, length between merus and propodus, with a row of serrate setae in the posterior margin; propodus ovate, length about of 1.6 times longer than wide, anterior margin smooth, length about 2.6 times of maximum length of posterior margin, with a cluster of simple setae on border, disto-posterior border with comb-scales and five smaller simple setae, with detail of apex dactyl, presenting two robust cuspidate setae with accessory setae; palm slightly longer than posterior margin of propodus, with inclination transverse and convex, covered by simple and cuspidate setae of medium size; dactyl claw-like and smooth, not exceeding the palm margin in length, with one small plumose setae in outer margin. Pereopod 3 and 4 (Figs 5A, B): coxal plate of the pereopod 4 excavated posteriorly, in both pereopods the base is long with 3-6 setae on posterior margin; anterior margin of merus with two cuspidate setae, posterior margin of merus with 4-7 groups of cuspidate setae distributed on margin; posterior margin of carpus with five groups of cuspidate setae with accessory seta; posterior margin of propodus with seven groups of the cuspidate setae with accessory seta; dactyl with one small simple setae, the length of dactyl not reaching half of length of propodus. Pereopod 5 to 7 (Figs 5C���E): pereopod 5 small than pereopod 6 and 7, coxal plates bilobed, in coxal plate of pereopod 7 the posterior lobe is 1/3 small of the anterior lobe; base is long, with the anterior lobe rounded and margin serrated with setules, posterior margin with 3-4 cuspidate setae with accessory seta; merus, carpus and propodus are similar in length, anterior margin of the merus with 2-4 cuspidate setae, posterior margin of the merus and carpus with three pairs of cuspidate setae with accessory seta; posterior margin of the propodus with four pair of cuspidate setae with accessory seta; dactyl not reaching half of length of propodus. Pleopods (Fig. 6A) similar, peduncle long and smooth; ramus longer than peduncle, with plumose setae densely distributed for the length of the ramus. Uropod 1 (Fig. 6B) peduncle longer than wide, slightly longer than the ramus, with seven cuspidate setae with accessory seta on superior margin; ramus similar in length and wide, outer ramus with five cuspidate setae with accessory setae distributed along the superior margin of the ramus, apex with two cuspidate setae; inner ramus with four cuspidate setae with accessory setae on the outer side of the ramus, inner side with curved seta reaching the apex of the ramus, followed by three smaller setae arranged in a row, apex with two cuspidate setae. Uropod 2 (Fig. 6C) peduncle slightly longer than the ramus, with four cuspidate setae with accessory seta; ramus similar in length and wide, outer ramus with five cuspidate setae with accessory seta; inner ramus with six cuspidate setae with accessory seta; in both, the apex has two cuspidate setae. Uropod 3 (Fig. 6D) shorter than the peduncle of uropod 1; peduncle longer than wide, similar to the length of the ramus with up to three basal small simple setae, apex with four cuspidate setae with accessory seta and one simple setae; ramus slender with six simple setae apically and one cuspidate seta small and robust. Telson (Fig. 6E) longer than wide; apex with rounded borders with two cuspidate setae with accessory seta and three simple setae. Coxal gills sac-like present on pereonites 2 to 6. Sternal gills tubular present on pereonites 2 to 7. Description of female. CCUFLA 440, body length: 8.3 mm; head length 1.0 mm. Antenna 1 (Fig. 7A): 3.1 mm; peduncle formed by three articles; first article longer than wide and larger than the others article; flagellum composed of 10 articles, with groups of simple setae. Antenna 2 (Fig. 7B): 4.2 mm; reaching half the length of the body; peduncle formed by three articles, greater than the length of the head; flagellum with 13 articles, with groups of simple setae. Gnathopod 1 (Fig. 7C, D) subchelate; long base, with one simple seta at the posterior margin, disto-posterior margin with seven long and slender simple setae; ischium with comb-scales on the posterior margin and seven simple long and slender setae on the distal margin; merus with the disto-posterior margin ovoid, with comb-scales and eight long and slender simple setae; carpus longer than wider, posterior margin convex, forming a shell-like structure, covered by serrate setae arranged in a row on the margin, inner surface of the carpus with seven long and slender simple setae, anterior margin smooth, distal margin with serrate setae; propodus longer than wide and widened distally; length about 1.4 times of maximum width, hammer-shaped, anterior margin with three simple setae, disto-anterior and disto-posterior margin covered by comb-scales, disto-anterior margin with a cluster of simple setae, disto-posterior margin with five small simple setae, inner surface with nine serrate setae arranged in two rows; outer face of propodus not observed; straight palm, length about 1/2 smaller than length of posterior margin of propodus, covered by smaller cuspidate setae with accessory seta and simple setae of the medium-sized, and two simple setae long and slender, disto-posterior margin of the palm with one robust cuspidate seta with accessory seta; dactyl claw-like, not exceeding the length of the palm, covered by comb-scales with a small plumose seta on the posterior margin. Gnathopod 2 (Fig. 7E, F) subchelate; long base with three setae on the margin, disto-posterior margin with seven long simple setae; ischium with comb-scales on the posterior and distal margins with eight simple long and slender setae; merus with comb-scales on the posterior margin, distal margin ovoid with a group of long simple setae distributed; carpus longer than wide, posterior margin convex, forming a shell-like structure, with serrate setae arranged in a row on the distal margin, inner surface with four long simple setae, anterior margin with a simple seta, disto-anterior margin with nine long simple setae; propodus rectangular, longer than wide, with length about 1.8 times than of maximum width,, anterior margin with long simple setae, disto-anterior and disto-posterior margin covered by comb-scales, disto-anterior margin with a group of long simple setae, posterior margin with four small simple setae, inner surface with four serrate setae; palm straight and length about 1/2 smaller than length of posterior margin of propodus, with small cuspidate and simple setae, three long and the others of medium-size, disto-posterior margin with one robust cuspidate seta with accessory seta; dactyl claw-like, not exceeding the length of the palm, covered by comb-scales and with small plumose seta on the posterior margin. Presence of foliaceous oostegites on pereonite, with curl-tipped setae on the margin. Intraspecific variation. The number of setae in the inner ramus of uropod 2 varied in some males, where it presented five cuspidate setae with accessory seta instead of six (Fig. 8A). There was also variation in the format and number of setae in the telson, where a quadrangular shape of the telson was observed, with the presence of 5-6 cuspidate setae with accessory seta, without the presence of simple setae (Fig. 8B). Measurements: For males, the mean body length was of 5.64 �� 1.4 mm, while the mean head length was of 0.7 �� 0.16 mm (n=52). The smallest male specimen had 3.1 mm of body length, and 0.5 mm of head length, while the largest male reached 8.2 mm of body length, with head length reaching 1.0 mm. For females, the mean body length was of 5.4 �� 1.5 mm, and the mean head length was of 0.68 �� 0.18 mm (n=130). The body size of the smallest female reached 2.4 mm and the head length, 0.4 mm, while the body size of the largest female measured 11.0 mm and its head length, 1.0 mm. Etymology. The specific name is a homage to the first inhabitants of the municipality, the Minuanos Indians, who, together with the Carij�� and Charrua Indians, previously inhabited the municipality of S��o Jos�� do Norte, the type of locality of species. Habitat. Freshwater, epigean. Hyalella minuana n. sp. was found in intermittent ponds, one without and the other with physical connection with other water bodies, with a size smaller than the one-hectare showing emergent and floating vegetation. Distribution. Specimens of Hyalella minuana n. sp. were found in two wetlands along the Rio Grande Sul state coast, distant from each other ca of 21.6 km. Site P1 (Fig. 1) is a temporary pond with a total area of ca 1,908 m ��, connected to another water body, depth of ~ 50 cm and tree vegetation. Site P2 (Fig. 1) is similar to Site 1, but is environmentally more heterogeneous, with water depth varying more than 20 cm, and without hydrologic connection with other water bodies, showing a total size-are of ca 4,801 m ��. Both sites showed emergent and floating vegetation. Taxonomic remarks. Hyalella minuana n. sp. shares some similarities with most species of the genus, mainly the presence of curved seta in the inner ramus of the uropod 1, characteristic of many species of the genus. Hyalella minuana n. sp. presents body surface smooth, differing from H. kaingang Araujo & Cardoso, 2013, H. pleoacuta Gonz��lez, Bond-Buckup & Araujo, 2006 and H. pseudoazteca Gonz��lez & Watling, 2003 that present dorsal flanges in some segments. Hyalella palmeirensis Streck-Marx & Castiglioni, 2020 resembles Hyalella minuana n. sp. due to the number of setae on the peduncle of uropod 3. However, while H. palmeirensis shows one pappose setae on the inner margin of the maxilla 2, Hyalella minuana n. sp. shows two pappose setae. Also, H. palmeirensis exhibits five serrate setae on the inner surface of the propodus of gnathopod 1, while Hyalella minuana n. sp. have nine serrate setae. Hyalella curvispina Shoemaker, 1942 also resembles Hyalella minuana n. sp. for presenting two pappose setae on the inner margin of the maxilla 2 and three cuspidate setae on the peduncle of uropod 3. However, both species show differences concerning the number of setae on the inner surface of gnathopod 1 and in size and type of the setae on telson. Hyalella curvispina has 5���7 setae on inner margin of gnathopod 1 and its telson is wider than long, with three simple setae. In turn, Hyalella minuana n. sp. present nine serrate setae on inner surface on gnathopod 1 and its telson is longer than wide, showing three cuspidate setae and simple setae. Hyalella castroi Gonz��lez, Bond-Buckup & Araujo, 2006, H. bonariensis Bond-Buckup, Araujo & Santos, 2008, H. georginae Streck & Castiglioni, 2017, H. gauchensis Streck & Castiglioni, 2017 and H. pampeana Cavalieri, 1968, differs from Hyalella minuana n. sp. in the number and disposition of the setae on uropods, form of telson, as well as in number and disposition of the setae on apex. Two new species of Hyalella were recently described for the state of Santa Catarina, H. catarinensis Reis & Bueno, 2020 and H. rioantensis Penoni & Bueno, 2020. Hyalella catarinensis differs from Hyalella minuana n. sp. in the number of setae on the inner surface of gnathopod 1 (H. catarinensis has four pappose setae; Hyalella minuana n. sp. shows nine serrate setae). In addition, H. catarinensis shows five cuspidate setae on the peduncle of uropod 1, while Hyalella minuana n. sp. shows seven cuspidate setae. In the peduncle of uropod 2, H. catarinensis has three cuspidate setae, while Hyalella minuana n. sp. has four cuspidate setae. In turn, H. rioantensis differs from Hyalella minuana n. sp. for not having papposerrate setae on the inner plate of the maxilla 2, and by the absence of serrate setae on the inner surface of the gnathopod 1. In addition, H. minuana n. sp., H. catarinensis and H. rioantensis present the propodus ovate; the maxilliped presents comb-scales only in H. rioantensis, being absent in H. minuana n. sp. and H. catarinensis, while H. minuana n. sp. present serrate setae on the maxilliped, and H. catarinensis and H. rioantensis present pappose setae; in the three species the coxal plate is excavated posteriorly, being slightly longer than wide in H. minuana n. sp., longer than wide in H. catarinensis, and deeper than wide in H. rioantensis., Published as part of Talhaferro, Jordan Tuparai, Bueno, Alessandra Ang��lica De P��dua, Pires, Mateus Marques, Stenert, Cristina, Maltchik, Leonardo & Kotzian, Carla Bender, 2021, Three new species of Hyalella (Crustacea: Amphipoda: Hyalellidae) from the Southern Brazilian Coastal Plain, pp. 257-292 in Zootaxa 4970 (2) on pages 259-269, DOI: 10.11646/zootaxa.4970.2.2, http://zenodo.org/record/4761718, {"references":["Watling, L. (1993) Functional morphology of the amphipod mandible. Journal of Natural History, 27 (4), 837 - 849. https: // doi. org / 10.1080 / 00222939300770511","Gonzalez, E. R., Bond-Buckup, G. & Araujo, P. B. (2006) Two new species of Hyalella from Southern Brazil (Amphipoda: Hyalellidae) with a taxonomic key. Journal of Crustacean Biology, 26, 355 - 365. https: // doi. org / 10.1651 / c- 2599.1","Streck-Marx, M. T. & Castiglioni, D. D. S. (2020) A new species of freshwater amphipod (Crustacea, Amphipoda, Hyalellidae) from state of Rio Grande do Sul, Southern Brazil. Biota Neotropica, 20 (1), e 20190802. https: // doi. org / 10.1590 / 1676 - 0611 - bn- 2019 - 0802","Streck, M. T., Cardoso, G. M., Rodrigues, S. G., Graichen, D. A. S. & Castiglioni, D. S. (2017) Two new species of Hyalella (Crustacea, Amphipoda, Hyalellidae) from state of Rio Grande do Sul, Southern Brazil. Zootaxa, 4337 (2), 263 - 278. https: // doi. org / 10.11646 / zootaxa. 4337.2.5","Reis, G. O., Penoni, L. R. & Bueno, A. A. P. (2020) First record of the genus Hyalella (Amphipoda: Hyalellidae) from Santa Catarina State, Brazil, with description of two new species. Biota Neotropica, 20 (2), e 20190879. https: // doi. org / 10.1590 / 1676 - 0611 - bn- 2019 - 0879"]}

Hyalella lagoana Talhaferro & Bueno, n. sp. (Figs 9���14) Type locality. Os��rio municipality, Rio Grande do Sul state, Brazil, sampling site P3 (30�� 02��� 44.8��� S, 50�� 40��� 36.6��� W). Type specimens. Holotype: male, body length = 7.0 mm; head length = 0.8 mm (MZUSP 41789), Os��rio municipality (30�� 02��� 44.8��� S, 50�� 40��� 36.06��� W), October 2015, Pires, M. M. & cols. Allotype: female, body length = 0.7 mm, head length = 5.4 mm (MZUSP 41790), same locality as holotype. Paratypes: MZUSP 41791, 10 whole specimens (5 males and 5 females); CCUFLA 441, 10 whole specimens (5 males and 5 females), 3 males and 1 female on slides; CRU0014, 145 whole specimens (24 males, 72 females and 49 juveniles) and 2 males on slides (same collection data of the holotype). Additional specimens. CRU0015, 4 whole specimens (2 female and 2 juvenile) and 4 males on slides, Garopaba municipality, Santa Catarina state, Brazil, sampling site P8 (28�� 03��� 96.12��� S, 48�� 61��� 31.21��� W), October 2015, Pires, M. M. & cols. Diagnosis. Body surface smooth. Eyes ovoid, large and pigmented. Antenna 1 approximately 1/4 smaller than antenna 2. Palp of the maxilla 1 uniarticulate and oval with apex covered by setules. Plates of maxilla 2 similar in length and width, inner plate with two papposerrate setae in the inner margin. Propodus of gnathopod 1 hammershaped, longer than wide, with four serrate setae on the inner surface. Peduncle of the uropod 1 with seven cuspidate setae on the margin, inner side of the inner ramus with four cuspidate setae, with curved setae reaching the apex of the ramus (male). Uropod 2 longer than the peduncle of uropod 1, peduncle with five cuspidate setae, inner ramus with seven cuspidate setae and outer ramus with six cuspidate setae. Sternal gills on pereonites 2 to 7. Description of male. Mean of body length: 6.74 �� 0.43 mm (n=5), mean of head length: 0.78 �� 0.07 mm (n=5). Body surface smooth. Eyes ovoid and pigmented. Epimeral plate not acuminated (Fig. 9A). Antenna 1 (Fig. 9B): 3.0 mm; peduncle with three articles; first article longer than wide and with robust cuspidate setae on the distal margin; flagellum with 13 articles, each article presents a group of simple setae. Aesthetascs were not observed. Antenna 2 (Fig. 9C): 4.0 mm; peduncle longer than head length; flagellum with 14-15 articles presenting groups of simple setae. Basic amphipodan mandible type (in sensu of Watling 1993) with palp absent. Right mandible (Fig. 9D) incisor process with five teeth, and two pappose setae. Left mandible (Fig. 9E) incisor process with five teeth; lacinia mobilis with four teeth; three pappose setae and setules below the lacinia. In both mandibles, the molar process is cylindrical, large, and triturative, with single long pappose seta on the inner margin, superior margin of the molar process with setules. Upper lip (Fig. 9F) showing outer borders ovoid, with simple setae on the borders, covered by several setules. Lower lip (Fig. 9G) bilobed, with simple setae and several setules on the inner and ventral margins, outer margins smooth. Maxilla 1 (Fig. 9H) palp uniarticulate, margins covered by setules, apex ovoid with a single apical seta, length not reaching half the distance between the palp base and the base of the setae on the apex of the outer plate; outer plate with nine serrate setae at the apex; inner plate slender, reaching half the length of the outer plate, margins covered by setules, and apex with two papposerrate setae of equal size. Maxilla 2 (Fig. 9I) plates similar in length and width; inner plate longer than wide, apex covered with serrate setae and few simple setae, inner margin with two papposerrate setae, inner seta short and slender, outer seta long and robust; outer plate longer than wide, apex covered by long serrate setae and a few smaller simple setae. Maxilliped (Fig. 9J) inner plate 1/3 smaller than the outer plate, inner margin with six pappose setae, apex rounded with three cuspidate setae in cone-shaped, and smaller pappose setae, outer margin smooth; outer plate reaching half the length of the article 2, inner margin covered by simple setae, outer margin smooth; palp with four articles, articles 1 and 2 with several simple setae on inner margin; inner margin of the article 3 covered by long and slender simple setae, outer distal margin with a group of simple and serrate setae; article 2 and 3 with many setules; dactyl longer than wide, with sub-apical simple setae and apex with a single long serrate setae. Gnathopod 1 (Figs 10A, B) subchelate; long base, with one simple seta on the posterior margin, distal margin with a group of simple setae; ischium with comb-scales and simple setae on the posterior margin; merus similar in length to the ischium, longer than wide, distal margin ovoid with six simple setae; carpus longer than wide, distoanterior margin with a group of serrate setae, inner surface with six simple setae, posterior lobe elongated, forming a shell-shaped structure with a margin covered by serrate setae; propodus longer than wide, length about 1.6 times of maximum width, hammer-shaped, inner face with four serrate setae and a few smaller simple setae, disto-anterior margin with comb-scales and one simple seta, disto-posterior margin with comb-scales and cup for dactyl; outer face of propodus not observed; palm transverse and slightly convex, length about 1/3 smaller than posterior margin length of propodus, covered by simple and cuspidate setae with accessory seta and two long and slender simple setae, distal margin of the palm with two robust cuspidate setae with accessory seta; dactyl claw-like, covered by comb-scales and congruent of the palm length, outer margin with comb-scales and one small plumose seta. Gnathopod 2 (Figs 10C, D) subchelate; showing a long base, with two simple setae on the posterior margin; disto-posterior margin with groups of long and slender simple setae; ischium as long than wide, with group of simple setae on the disto-posterior margin; merus slightly longer than wide, posterior margin ovoid with long and slender simple setae; carpus as long than wide, disto-anterior margin with serrate setae, posterior lobe convex, shell-like shape, covered with serrate setae; propodus ovate, long than wide, length about 1.2 times of maximum width, distoanterior margin with a group of long simple seta, disto-posterior margin covered by comb-scales, posterior margin with one simple seta of intermediate size, inner face with a few simple and smaller setae; palm slightly convex, longer than posterior margin of the propodus (1.2 times), covered by simple and cuspidate setae with accessory seta; disto-posterior margin with two robust cuspidate setae with accessory seta; dactyl claw-like, smooth and congruent of the palm length, with small plumose setae on the outer margin. Pereopods 3 and 4 (Figs 11A, B) similar in size; the coxal plate of the pereopod 4 excavated posteriorly; the base with 4-5 simple setae on the posterior margin in the pereopod 3; in both pereopods, merus longer than carpus with 4-6 groups of simple setae on the posterior margin; carpus with five cuspidate setae on the posterior margin with simple setae; propodus similar to the carpus in length, with seven cuspidate setae on the posterior margin with simple setae; dactyl not reaching half the length of the propodus, with simple seta subapical. Pereopods 5 to 7 (Figs 11C���E): coxal plate bilobed; pereopod 7 with the posterior lobe 1/3 the size of the anterior lobe; pereopod 5 smaller than 6 and 7; pereopods 6 and 7 similar in size; base with anterior margin ovoid, posterior margin with cuspidate setae; merus with cuspidate setae on the anterior and posterior margins; carpus and propodus with pairs of cuspidate setae on the posterior margin; dactyl not reaching half the length of the propodus, with simple seta subapical. Pleopods (Fig. 12A) similar, peduncle longer than wide, approximately 1/2 the length of the ramus; ramus with plumose setae distributed densely over the entire length. Uropod 1 (Fig. 12B) peduncle larger than the ramus and longer than wide, with seven cuspidate setae with accessory setae; ramus similar in length and width; outer ramus with six cuspidate setae with accessory setae, apex with two cuspidate setae; inner ramus with four cuspidate setae with accessory setae on the outer side of the ramus, curved setae on the inner side of the ramus reaching the apex, followed by three cuspidate setae arranged in a row, with decreasing size, apex with two robust cuspidate setae. Uropod 2 (Fig. 12C) larger than the peduncle of uropod 1; peduncle slightly smaller than the ramus, longer than wide, with five cuspidate setae with accessory seta; ramus similar in length and width; outer ramus with six cuspidate setae with accessory seta, apex with two cuspidate setae; inner ramus with seven cuspidate setae with accessory seta, apex with two robust cuspidate setae. Uropod 3 (Fig. 12D) smaller than the peduncle of uropod 1; peduncle with five cuspidate setae with accessory seta and a simple seta; peduncle slightly longer than the ramus, with six long and slender simple setae and small robust cuspidate seta. Telson (Fig. 12E) as longer than wide, apex rounded, with six cuspidate setae with accessory seta and two simple setae at the apex. Coxal gills sac-like present on pereonites 2 to 6. Sternal gills tubular present on pereonites 2 to 7. Description of the female. CCUFLA 441, body length: 6.0 mm, head length 0.8 mm. Antenna 1 (Fig. 13A): 2.0 mm, smaller than antenna 2; peduncle formed by three articles; first article longer than wide with three long and robust simple setae on the margin, distal border with cuspidate seta; first at the second article wider than the third, and similar in length; third article smaller than the two others, in wide and length; flagellum with 9 articles, all with a group of simple setae. Antenna 2 (Fig. 13B): 2.7 mm; peduncle formed by three articles and longer than the length of the head; first article wider than the others, with half the length of the other two articles; second article wider than the third, with similar length; flagellum with 12 articles, all with a group of simple setae. Gnathopod 1 (Figs 13C, D) subchelate; base with long and slender simple setae on the disto-posterior margin; ischium slightly longer than wide, with a group of long and slender simple setae on the disto-posterior margin; merus similar in length and width, disto-posterior margin rounded, with long simple setae; carpus longer than wide, posterior margin smooth, disto-anterior border with a group of long and slender simple setae, posterior margin convex, forming a shell-like structure and covered by serrate setae, inner margin with five simple setae arranged in a row; propodus longer than wide, length about 1.4 times of maximum width, hammer-shaped; anterior margin with two simple setae; disto-anterior and disto-posterior border covered by comb-scales, inner margin with six serrate setae arranged in one row; outer face of propodus not observed; palm slightly convex, length about 1/3 smaller than posterior margin length of propodus, covered by simple setae of intermediary-size and small cuspidate setae, the disto-posterior border with a one small and robust cuspidate seta with accessory seta; dactyl claw-like, not exceeding the length of the palm, covered by comb-scales and with four setules distributed along the inner margin, outer margin with a one simple seta. Gnathopod 2 (Fig. 13E, F) subchelate; long base with a long central simple seta in the posterior margin and a group of simple setae on the disto-posterior margin; ischium slightly longer than wide with comb-scales and long simple setae on the disto-posterior margin; merus longer than wide, the disto-posterior margin rounded with combscales and a group of long simple setae; carpus longer than wide, less than 2 times the length of width, anterior margin smooth, the distal border with a group of simple setae, posterior margin convex, forming a shell-like structure covered by serrate setae, inner margin with two long simple setae; propodus rectangular shape, longer than wide, length about 1.8 times of maximum width, anterior margin with a simple seta and comb-scales, posterior margin with four simple setae and comb-scales from the central region to the distal border, inner surface with three serrate setae arranged in one row; palm slightly convex, length about 2.3 times smaller than maximum posterior margin length of propodus, covered by simple setae, the central region with two long and slender simple setae, the distoposterior border with two small and robust cuspidate setae with accessory seta; dactyl not exceeding the length of the palm, claw-like, covered by comb-scales and with four setules distributed along the inner margin, outer margin with a simple setae. Presence of foliaceous oostegites on pereonite, with curl-tipped setae on the margin. Intraspecific variation. There was variation in some individuals in the number of bristles in the peduncle and branches of the uropod 3. The peduncle showed three instead of five cuspidate setae with accessory seta, the ramus showed the number of similar subapical setae, however, the number of distal setae differed in both rami, showing only two setae in both (Fig. 14A). The telson differed in some individuals that presented a different apex shape, with the rounder and less wide margins, in addition to having some tiny and robust cuspidate setae and the absence of simple setae (Fig 14B). Measurements. For males, the mean body length was of 6.15 �� 0.9 mm, while the mean head length was of 0.71 �� 0.13 mm (n=43). The smallest male specimen had 3.1 mm of body length, and 0.5 mm of head length, while the largest male reached 90 mm of body length, with head length reaching 0.9 mm. For females, the mean body length was of 5.1 �� 1.0 mm, and the mean head length was of 0.63 �� 0.14 mm (n=85). The body size of the smallest female reached 3.1 mm and the head length, 0.4 mm, while the body size of the largest female measured 8.2 mm and its head length, 1.0 mm. Etymology. The specific name, lagoana, refers to large numbers of ponds found in Os��rio municipality (23 ponds to all), also known as ���Cidade das lagoas���, type locality of species. Habitat. Freshwater, epigean. Hyalella lagoana n. sp. was found in intermittent ponds, the hydrological connection with other water bodies is present in a single pond, in both ponds, the size-area is smaller than the one-hectare, and feature emergent and floating vegetation. Distribution. Hyalella lagoana n. sp. were registered in two sampling sites. Site P3 is an intermittent pond located in the Rio Grande do Sul (Fig. 1), showing a total size-area of 1,387 m ��, depth uniform, and inferior to 50 cm. This site is isolated from other water bodies and shows no arboreous vegetation near their banks. Sampling site P8 is located in Santa Catarina (Fig. 1), shows a total area of ca. 3,500 m ��, and is environmentally similar to site 3. However, its depth is not uniform along its area varying more than 20 cm, but not surpassing 50 cm. Its hydroperiod is permanent, and it is connected to other water bodies. Both, sites P3 and P8 contain emergent and floating vegetation in the margins. Taxonomic remarks. Hyalella lagoana n. sp. shares important characteristics with other species, such as presence of curved seta on the inner ramus of uropod 1, that also occurs in H. georginae, H. gauchensis, H. montenegrinae Bond-Buckup & Araujo, 1998, H. curvispina, H. castroi, H. kaingang, H. pleoacuta, H. carstica Bastos-Pereira & Bueno, 2012, H. xakriaba Bueno & Araujo, 2013, H. palmeirensis and H. bonariensis. However, Hyalella lagoana n. sp. differs from H. kaingang, H. pleoacuta and H. pseudoazteca, due to the absence of flanges in pereon and in pleonites. Hyalella lagoana n. sp. is similar to H. montenegrinae and H. pampeana due to the number of setae on the peduncle of uropod 3 and to the presence of two papposerrate setae in the inner margin of the inner plate of the maxilla 2. Hyalella lagoana n. sp. differs from H. montenegrinae and H. pampeana in characteristics related to the number of flagellum on the antennae 1 and 2, number of serrate on the inner surface of gnathopod 1 and in the form and number of setae on telson. Hyalella lagoana n. sp. also differs from H. georginae, H. gauchensis, H. curvispina, H. castroi, H. carstica, H. xakriaba, H. palmeirensis and H. bonariensis by the number of flagellum on the antennae 1 and 2, of serrate setae on the inner surface of the propodus of gnathopod 1, as well as by the number and disposition of setae on uropods, form of telson, and by the type and disposition of setae on the apex of the telson. Hyalella lagoana n. sp. also shares similarities with two species recently described for the Santa Catarina state (Reis et al. 2020). However, it differs from H. catarinensis by the number of papposerrate setae on the inner plate of the maxilla 2 (H. catarinensis with one papposerrate seta on inner plate), and by the form and number of setae cuspidate on the telson (H. catarinensis with telson longer than wide, and with three cuspidate setae apical). Hyalella rioantensis differs from Hyalella lagoana n. sp. for presenting four cuspidate setae on the apex of telson, four to six cuspidate setae on the peduncle of uropod 1, and three or four cuspidate setae on the peduncle of uropod 2. In addition, Hyalella lagoana n. sp. differs from Hyalella minuana n. sp. in number of the teeth on lacinia mobilis of the left mandible (Hyalella lagoana n. sp. with four teeth, Hyalella minuana n. sp. with five teeth); the number of pappose setae on the inner plate of the maxilliped (Hyalella lagoana n. sp. with six pappose setae; Hyalella minuana n. sp. with seven pappose setae); and the number of serrate setae on the inner surface of gnathopod 1 (Hyalella lagoana n. sp. with four serrate setae; Hyalella minuana n. sp. with nine serrate setae)., Published as part of Talhaferro, Jordan Tuparai, Bueno, Alessandra Ang��lica De P��dua, Pires, Mateus Marques, Stenert, Cristina, Maltchik, Leonardo & Kotzian, Carla Bender, 2021, Three new species of Hyalella (Crustacea: Amphipoda: Hyalellidae) from the Southern Brazilian Coastal Plain, pp. 257-292 in Zootaxa 4970 (2) on pages 270-279, DOI: 10.11646/zootaxa.4970.2.2, http://zenodo.org/record/4761718, {"references":["Watling, L. (1993) Functional morphology of the amphipod mandible. Journal of Natural History, 27 (4), 837 - 849. https: // doi. org / 10.1080 / 00222939300770511","Bastos-Pereira, R. & Bueno, A. A. P. (2012) New species and new report of Hyalella S. I. Smith, 1874 (Crustacea: Amphipoda: Dogielinotidae) from Minas Gerais state, Southeastern Brazil. Zootaxa, 3350, 58 - 68. https: // doi. org / 10.11646 / zootaxa. 3350.1.4","Reis, G. O., Penoni, L. R. & Bueno, A. A. P. (2020) First record of the genus Hyalella (Amphipoda: Hyalellidae) from Santa Catarina State, Brazil, with description of two new species. Biota Neotropica, 20 (2), e 20190879. https: // doi. org / 10.1590 / 1676 - 0611 - bn- 2019 - 0879"]}

Hyalella sambaqui Talhaferro & Bueno, n. sp. (Figs 15–20) Type locality. Passo de Torres municipality, Santa Catarina state, Brazil, sampling site P4 (29º 32’ 08” S, 49º 72’ 39” W). Type specimens. Holotype: male, body length = 8.1 mm, head length = 0.9 mm (MZUSP 41792), Passo de Torres municipality (29º 26’ 75.29” S, 49º 74’ 23.31” W), October 2015; Pires, M. M & cols. Allotype: female, body length = 5.0 mm, head length = 0.6 mm (MZUSP 41793), same locality as holotype. Paratypes: MZUSP 41794, 10 whole specimens (5 males and 5 females); CCUFLA 442, 10 whole specimens (5 male and 5 female) and 4 males and 1 female on slides; CRU0016, 514 whole specimens (131 males, 205 females and 178 juveniles) and 2 males on slides (same collection data of the holotype). Additional specimens. CRU0017, 34 whole specimens (6 males and 28 females), and 5 males on slides; Balneário da Gaivota municipality, Santa Catarina state, Brazil, sampling site P5 (29º 13’ 02.58” S, 49º 62’ 02.09” W), October 2015; Pires, M. M & cols. CRU0018, 429 whole specimens (64 males, 95 females and 270 juveniles), and 5 males on slides; Balneário Arroio do Silva municipality, Santa Catarina state, Brazil, sampling site P6 (28º 98’ 22.17” S, 49º 42’ 57.15” W), October 2015; Pires, M. M. & cols. CRU0019, 7 whole specimens (6 females and 1 juvenile), and 1 male on slide; Jaguaruna municipality, Santa Catarina state, Brazil, sampling site P7 (28º 62’ 78.68” S, 48º 90’ 82.36” W), October 2015; Pires, M. M. & cols. Diagnosis. Body surface smooth. Eyes ovoid and pigmented. Antenna 1 shorter than antenna 2. Inner plate of maxilla 1 slender with 1/3 the width of the outer plate, with two unequal papposerrate apical setae. The inner plate of maxilla 2 with one long and one shorter papposerrate setae of inner margin. Propodus of gnathopod 1 hammershaped, inner face with six serrate setae. Uropod 1 with curved setae on inner side of inner ramus. Sternal gills on pereonites 2 to 7. Description of male: Mean of body length: 5.31 ± 0.61 mm (n=6), mean of head length: 0.68 ± 0.06 mm (n=6). Body surface smooth. Eyes ovoid and pigmented. Epimeral plate slightly acuminate (Fig 15A). Antenna 1 (Fig. 15B) shorter than antenna 2 (1/4 times); shorter than half body length; peduncle slightly longer than head length, all segments of peduncle with group of simple and cuspidate setae; first article longer than second; third article slightly shorter than second; flagellum with 9 articles, longer than peduncle, with group of simple setae occurring on all articles. Aesthetascs were not observed. Antenna 2 (Fig. 15C) reaching half the length of the body; peduncle slightly longer than head length; flagellum with 13 articles, longer than peduncle, with a group of simple setae occurring on all articles. Basic amphipodan mandible type (in sensu of Watling 1993), with palp absent. Right mandible (Fig. 15D) incisor process with four denticles, and two pappose setae. Left mandible (Fig. 15E) incisor process with six denticles; lacinia mobilis with seven denticles (four long, three short), and three pappose setae under lacinia mobilis. In both mandibles, the molar process is large, cylindrical and triturative, with one long pappose seta on inner margin. Upper lip (Fig. 15F) margins rounded, distal borders covered by setules, and few smaller simple setae. Lower lip (Fig. 15G) outer lobes rounded, with many setules on ventral face and inner borders. Maxilla 1 (Fig. 15H) palp uniarticulate, not reaching half of the distance between the base of palp and base of setae on outer plate; inner plate slender, 1/3 shorter than the outer plate, with two apical pappose setae, with many setules along on the margins; outer plate with nine distal serrate setae. Maxilla 2 (Fig. 15I) inner plate subequal in length to outer plate; inner plate with one robust and one shorter papposerrate setae proximally on inner margin, apex with many serrate and simple setae; outer plate with many serrate and simple setae on the apex. Maxilliped (Fig. 15J) inner plate longer than wide, slightly shorter than outer plate, apically rounded with three cuspidate setae in cone-shaped, inner borders with five long pappose setae and apex of inner plate with many small pappose setae, surface dorsal with several setules; outer plate longer than wide, apically rounded, apex and inner border with several simple setae; palp with four articles, article 1 with 1 or 2 simple setae, inner margin with 1 to 3 simple setae; outer margin of article 2 with two simple setae and inner borders with a several long and slender simple setae; inner margin of article 3 with several long simple setae and apex with some papposerrate setae; dactyl smooth, apex with one long simple setae, and another three short simple setae subapical. Gnathopod 1 (Figs 16A, B) subchelate; basis longer than wide, with two small setae on dorsal margin and a group of simple setae on disto-posterior border; ischium longer than wider with a group of simple setae on distoposterior border; merus with disto-posterior border rounded with simple setae; carpus longer than wide, posterior lobe convex, forming a shell-shaped structure with many serrate setae distributed along the margin, inner surface with three simple setae, border disto-anterior with four long serrate setae; propodus longer than wide, length about 1.2 times of maximum width, hammer-shaped, inner face with five serrate setae arranged in one row, anterior and posterior margin with one simple setae, comb-scales on disto-anterior and disto-posterior border, disto-anterior border with a group of long simple setae; outer face of propodus not observed; palm flat with length shorter than posterior margin of propodus (1.9 times) and several simple setae (some long, some short), distal margin with one cuspidate seta with accessory seta; dactyl claw-like, reaching palm angle, covered by comb-scales and with one simple setae in the outer margin. Gnathopod 2 (Figs 16C, D) subchelate; basis long with three simple setae on dorsal margin, distal margin of basis and ischium with a group of simple setae; merus slightly longer than wider, posterior border rounded, with simple setae; carpus with posterior lobe elongated, forming a shell-shaped structure with many serrate setae distributed along the margin, disto-anterior margin with two simple setae; propodus ovate, length about 1.3 times of maximum width, with comb-scales on disto-posterior margin, margin disto-anterior with a cluster of short simple setae, anterior margin with one simple seta, and posterior margin with two or three simple setae; palm transverse, longer than posterior margin of propodus (1.2 times), slightly convex with several strong cuspidate medium-length and short setae, and some simple setae, distal margin of the palm with one cuspidate setae with accessory seta; dactyl claw-like and smooth, outer margin with one short simple seta and inner surface with six tiny setae, length congruent with palm. Pereopods 3 and 4 (Figs 17A, B) similar in size and shape; posterior margin of carpus and propodus with cuspidate setae with accessory seta and simple seta; posterior margin of merus and basis with simple setae; dactyl less than half the length of propodus, surface smooth with simple seta. Coxal plates longer than wide, pereopod 4 excavated posteriorly; both coxal plates with small simple setae on margin, outer surface covered with microtrichs. Pereopods 5 to 7 (Figs 17C–E): coxal plate of pereopod 5 wider than long with two lobes, anterior lobe slightly shorter than posterior; coxal plate of pereopod 6 wider than long with anterior lobe 1/3 of posterior lobe length; coxal plate of pereopod 7 wider than long with lobe unique; all coxal plates with small simple setae on margins and outer surface with covered by microtrichs. Pereopod 5 visibly shorter than pereopods 6 and 7, the latter two similar in length, posterior margin of basis of peraeopods 5 to 7 oval, less expanded in 6, borders finely serrate with simple setae; anterior margins of merus, carpus and propodus with groups of 2-5 cuspidate setae with one accessory seta on anterior margins; dactylus less than half the length of propodus, with simple seta. Pleopods (Fig. 18A) all pleopods similar, peduncle shorter than ramus, biramous, ramus multi-annulated and both ramus with many long plumose setae. Uropod 1 (Fig. 18B) peduncle slightly longer than ramus, peduncle with six cuspidate setae on dorsal surface with accessory setae; ramus subequal in length; inner ramus with two dorsal cuspidate setae with accessory seta, one long curved setae on inner side, four distal cuspidate setae with accessory setae (one long), and two cuspidate setae o the apex; outer ramus with three dorsal cuspidate setae with accessory setae, two subapical cuspidate setae with accessory seta, and two robust cuspidate setae on the apex. Uropod 2 (Fig. 18C) shorter than uropod 1, peduncle slightly longer than wide with four cuspidate setae on dorsal with accessory setae; inner ramus with two dorsal cuspidate setae with accessory seta, three subapical cuspidate setae with accessory seta and two cuspidate setae o the apex; outer ramus with two dorsal cuspidate setae with accessory seta, two subapical cuspidate setae with accessory seta and two cuspidate setae on the apex. Uropod 3 (Fig. 18D) shorter than peduncle of uropod 1, subequal in length in relation to peduncle of uropod 2; peduncle longer than wide and wider than ramus, with three simple setae on basis and three cuspidate setae with accessory seta on the apex; outer ramus inarticulate, slightly longer than peduncle, with three simple setae and one strong and smaller cuspidate setae apically. Telson (Fig. 18E) wider than long, apically rounded, bearing three cuspidate setae with accessory setae unsymmetrically distributed on the distal margin and two small plumose setae on both margin sides. Coxal gills sac-like, present on pereonites 2 to 6. Sternal gills tubular, present on pereonites 2 to 7. Description of the female. CCUFLA 442, body length: 4.30 mm; head length: 4.3 mm. Antenna 1 (Fig. 19A) shorter than antenna 2 (1/4 times), flagellum with eight articles. Antenna 2 (Fig. 19B) reaching half the length of the body, flagellum with nine articles. Gnathopod 1 (Figs 19C, D) subchelate; basis longer than wider; ischium and merus with comb-scales in posterior margin; posterior lobe of carpus convex, forming a shell-shaped structure with many serrate setae distributed along the margin, inner face with three long simple setae, disto-anterior margin with a group of simple setae; propodus slightly longer than wide, length about 1.2 times of maximum width hammer-shaped, comb-scales in distoposterior and disto-anterior margin, inner face with five serrate setae arranged in one row; outer face of propodus not observed palm margin slightly shorter than posterior margin length of propodus (1.3 times) with two long and slender simple setae with several simple and cuspidate setae smaller, distal margin with one robust cuspidate setae with accessory setae; dactyl claw-like with comb-scales, one plumose seta on dorsal margin, length reaching distal border of palm of propodus. Gnathopod 2 (Figs 19E, F) subchelate; basis, ischium, merus and carpus similar to gnathopod 1; propodus longer than wider, rectangular shape, length about 1.7 times of maximum width, differing from male gnathopod 2 in shape and size, inner face with four serrate setae arranged in one row, disto-anterior and disto-posterior border with several comb-scales, disto-posterior border with two simple setae; palm slightly flat, smaller than 1/2 the maximum posterior margin length of propodus with two long and slender simple setae and some smaller cuspidate setae with accessory seta, distal margin with only one small and robust cuspidate seta with accessory setae; dactyl claw-like, reaching the length of palm with comb-scales and one plumose seta on dorsal margin. Intraspecific variation. There was variation in the number of setae in the uropod 3, with a difference even between individuals. In some individuals, the peduncle presents six cuspidate setae, and a long simple seta on the inner margin of the peduncle. However, in the other peduncle the simple seta on the inner margin was absent, and the ramus shows a robust cuspidate seta, but the number of cuspidate setae is upper of three (Fig. 20A). The telson presented a different shape for some individuals, with a rectangular shape and the presence of four cuspidate setae on the apex and three small plumose setae on both margin sides (Fig. 20B). Measurements. For males, the mean body length was 5.57 ± 0.91 mm, while the mean head length was 0.62 ± 0.14 mm (n=229). The smallest male specimen had 3.2 mm of body length, and 0.3 mm of head length, while the largest male reached 8.3 mm of body length, with head length reaching 1.0 mm. For females, the mean body length was 4.7 ± 0.9 mm, and the mean head length was 0.56 ± 0.13 mm (n=346). The body size of the smallest female reached 2.4 mm and the head length, 0.3 mm, while the body size of the largest female measured 8.0 mm and its head length, 0.9 mm. Etymology. The specific name, sambaqui, is a word of Tupi etymology (tamba = shellfish, and ki = pilling-up). The term describes the main characteristics of the coastal region of Santa Catarina during the first arrivals from Europe, regions with enormous amounts of shellmounds. The term also is attributed to the first inhabitants of the region of the municipality of Passo de Torres, called “men of sambaqui”. Habitat. Freshwater, epigean. Hyalella sambaqui n. sp. was found in intermittent and temporary ponds, with a size-area smaller than one-hectare, depth with 50 cm (± 20 cm), and feature emergent and floating vegetation in the margins of the ponds. Distribution. Hyalella sambaqui n. sp. was recorded in four wetlands across the extension of the Coastal Plain of Santa Catarina (Fig. 1). The sites P4 and P5 feature permanent hydroperiod, while sites P6 and P7 has a temporary hydroperiod. Of the four collection sites, only site P5 is isolate, without hydrological connection with any other water bodies. In all sampling sites, there is the presence of herbaceous vegetation in margin of the ponds, with total size-area ranging from 2,306 m ² to 5,340 m ² and depth not exceeding 50 cm, ranging around 20 cm in the sites P4 and P6. Taxonomic remarks. In general, the new species shares some morphological characteristics of taxonomic importance with most epigean species of Hyalella from Southern of the Brazil. As well as most species Hyalella sambaqui n. sp. shows one long curved seta on the inner ramus of uropod 1 (except in H. pseudoazteca González & Watling, 2003, in which the curved seta is absent). Hyalella sambaqui n. sp. also shares with most other species of the genus the body surface smooth (except with H. kaingang, that has flanges on pleonites 1 and 2; H. pleoacuta, with flanges on pereion 7 and pleonites 1, 2 and 3; and H. pseudoazteca, with flanges on pereion 7 and pleonites 1 and 2). Hyalella sambaqui n. sp. shares some similarities with Hyalella palmeirensis, such as the number of serrate setae on the inner face of the propodus of gnathopod 1, the number of cuspidate setae on the inner side of the inner ramus of uropod 1, and the number of cuspidate setae on the peduncle of the inner and outer rami of uropod 2. However, both species differ in the number of setae in the peduncle of uropod 1 (H. palmeirensis shows four setae), number of apical and plumose setae on telson (H. palmeirensis has two long simple and three plumose setae), papposerrate setae in the inner plate of the maxilla 2 (H. palmeirensis shows one robust papposerrate setae), ornament on the distal inner margin of gnathopod 2 (absent in H. palmeirensis), setae on telson (H. palmeirensis with two long simple and three plumose accessory setae), and sternal gills in the pereonites (H. palmeirensis has gills in pereonites 3 to 7). Regarding the number of the articles of the flagellum in antennae 1 and 2, H. bonariensis present between 9–12 and 12–15 articles, respectively, being similar to Hyalella sambaqui n. sp., besides that share the presence of sternal gills in the pereonites from 2 to 7; the number of papposerrate setae on the inner plate of the maxilla 1; the number of serrate setae ventrally of the propodus of gnathopod 1. They differ in the setae of the inner plate of the maxilla 2 (H. bonariensis with two rows of simple setae; Hyalella sambaqui n. sp. with several serrulate and simple setae); peduncle of uropod 3 (H. bonariensis with six cuspidate and one simple setae; Hyalella sambaqui n. sp. with three cuspidate setae). As in H. sambaqui n. sp., H. gauchensis and H. georginae present plumose setae on the apex of the telson, however, differs in number of cuspidate setae on the inner and outer rami of uropod 1; the number of serrate setae on the inner face of the propodus of gnathopod 1 (H. sambaqui n. sp. with five serrate setae; H. gauchensis and H. georginae with 9 or 10 and 9 serrate setae, respectively), and in the outer plate of the maxilla 2 (H. gauchensis and H. georginae with several simple setae apically; and H. sambaqui n. sp. with many serrate and simple setae). Hyalella sambaqui n. sp. differs from H. castroi in the number and type of setae on the inner face of the propodus of gnathopod 1 (H. castroi with more than ten papposerrate setae), and the number and type of setae on the inner plate of the maxilla 2 (H. castroi with one strong pappose seta, and H. sambaqui n. sp. with two papposerrate setae on inner margin). Hyalella sambaqui n. sp. differs from H. curvispina in the number of setae on the inner face of the propodus of gnathopod 1 (H. curvispina with five to seven setae arranged to 3 rows), just like in the number of setae on the peduncle of uropod 1 (H. curvispina with seven setae), and the number of setae on the inner and outer rami of uropod 2 (H. curvispina with two or three distal setae and eight setae apically on the inner ramus, and the outer ramus with three distal setae and four setae apically). However, H. curvispina is similar to H. sambaqui n. sp. in the number of setae on the apex of the peduncle of uropod 3 (with three setae), but differs on the number of setae on the apex of the both rami of uropod 3 (H. curvispina with eight slender and one robust setae). Hyalella sambaqui n. sp. also resembles H. brasiliensis Bousfield, 1996 described from Rio dos Patos, Paraná state. The description of H. brasiliensis is old and shows few morphological information. However, it is possible to observe that both species show some similarities, such as the presence of sternal gills in the

We present an Odonata (Insecta) check list of species occurring in a fragment of the Seasonal Deciduous Forest (Atlantic Forest biome) from the central region of the state of Rio Grande do Sul (RS), southern Brazil, along with a list of the odonate species recorded in this phytoecological region for the state. In addition, we provide comments on the seasonal distribution of the species occurring in the study area. Two streams and seven farm ponds located in the middle course of the Jacuí River basin were surveyed between December 2007 and February 2009. Overall, we recorded 49 species from 21 genera and six families. Argia serva Hagen in Selys, 1865 (Coenagrionidade) had its first occurrence record mentioned for the state, elevating to 183 the total number of Odonata species occurring in Rio Grande do Sul. The number of species recorded in the study area corresponds to ~26% of the known Odonata diversity in RS. Libellulidae was the most species-rich family (22 species, ~45% of the total), followed by Coenagrionidae (18 species, 37% of the total). The checklist for the Seasonal Deciduous Forest in RS indicated the occurrence of 83 species of Odonata in this phytoecological region (~45% of the known odonate species in the state). This elevated diversity could be related to the density of the vegetation structure. In the study area, 20 species were found in streams, and 45 in farm ponds. Species occurrence showed marked seasonal patterns in the study area, with 88% of the species recorded from summer to autumn, and no species detected in streams in the winter. Moreover, 70% of the species were recorded in either one or two seasons in farm ponds, while 65% occurred solely in one season in streams. This result indicates that the life cycle of Odonata in southern Brazil is strongly influenced by seasonal patterns in temperature. Resumo: Uma checklist das espécies de Odonata (Insecta) de um fragmento de Floresta Estacional Decidual (Bioma Mata Atlântica) localizado na região central do estado do Rio Grande do Sul (RS) é apresentada neste estudo, bem como uma checklist das espécies para esta região fitoecológica para o estado. Além disso, também é discutida a distribuição temporal da ocorrência das espécies na área de estudo. Dois riachos e sete reservatórios localizados no trecho médio da bacia do rio Jacuí foram estudados entre dezembro de 2007 e fevereiro de 2009. Ao todo, 49 espécies de 21 gêneros e seis famílias foram registradas. Argia serva Hagen in Selys, 1865 (Coenagrionidade) teve seu primeiro registro mencionado para o estado, elevando para 183 o número total de espécies de Odonata ocorrentes no Rio Grande do Sul. O número de espécies registrado na área de estudo corresponde a cerca de 26% da diversidade de Odonata conhecida no RS. Libellulidae foi a família mais rica (22 espécies, ~45% do total), seguida por Coenagrionidae (18 espécies, 37% do total). A lista compilada de espécies para a Floresta Estacional Decidual no RS indicou a ocorrência de 83 espécies de Odonata nesta região fitoecológica (~45% da diversidade de Odonata conhecida do estado). Essa alta diversidade pode estar relacionada à densidade da estrutura da vegetação. Na área de estudo, 20 espécies foram encontradas em riachos e 45 em reservatórios. A distribuição temporal das espécies foi marcadamente sazonal na área de estudo, com 88% das espécies registradas do verão ao outono, e nenhuma espécie detectada em riachos no inverno. Além disso, 70% das espécies ocorreram em uma ou duas estações em reservatórios, enquanto 65% das espécies registradas em riachos foram detectadas somente em uma estação. Este resultado indica que o ciclo de vida das espécies de Odonata no extremo sul do Brasil é fortemente influenciado pelos padrões sazonais de temperatura.

AIMS: In this study, the diversity of Ephemeroptera, Plecoptera, Trichoptera and Coleoptera communities was surveyed in the Toropi River basin, a watershed localized in a slope region, in southernmost Brazil. The influence of some local abiotic factors on the most common genera was also analyzed. METHODS: Samplings were conducted at 40 sites in 1st-4th order streams, along a short elevation gradient (70-500 m), with a Surber sampler. Water physico-chemical factors, as well as substrate type, were obtained at each site. RESULTS: At all, 5,320 specimens were collected, belonging to 18 families and 52 genera. The caddisflies Austrotinodes and Celaenotrichia, and an undescribed Elmidae, Genus M, are new records for the region. The caddisfly Smicridea was the most frequent genus in the study area. The mayflies Camelobaetidius, Paracloeodes and Americabaetis were influenced by stream order. Smicridea was related to air temperature, while the mayfly Thraulodes was influenced by high levels of electrical conductivity. CONCLUSIONS: The high diversity found in the study area, compared to other Brazilian regions, reflects the environmental heterogeneity in the region. These data show that hydrographic basins in slope areas from extreme Southern Brazil sustain high levels of diversity of aquatic insect communities. OBJETIVOS: Neste estudo a diversidade de comunidades de Ephemeroptera, Plecoptera, Trichoptera e Coleoptera foi analisada em riachos da Bacia do Rio Toropi, localizada em uma região de encosta, no extremo sul do Brasil. A influência de alguns fatores abióticos sobre os gêneros mais frequentes também foi analisada. MÉTODOS: As coletas foram realizadas em 40 locais, em riachos de 1ª a 4ª ordem, ao longo de um gradiente altitudinal curto (70-500 m), com amostrador Surber. Fatores físico-químicos da água, bem como o tipo de substrato, foram medidos em cada local. RESULTADOS: Ao todo, 5320 exemplares foram coletados, atribuídos a 18 famílias e 52 gêneros. Os tricópteros Austrotinodes, Celaenotrichia e um elmídeo não descrito, Gênero M, são ocorrências novas no estado. O tricóptero Smicridea foi o gênero mais freqüente na área de estudo como um todo. Os efemerópteros Camelobaetidius, Paracloeodes e Americabaetis foram influenciados pela ordem dos rios. Smicridea foi relacionado com a alta temperatura do ar, enquanto o efemeróptero Thraulodes foi influenciado pelo aumento da condutividade elétrica. CONCLUSÕES: A alta diversidade encontrada na região estudada, comparada a de outras regiões brasileiras, é resultado da heterogeneidade ambiental da região de amostragem. Estes dados mostram que rios da encosta do Planalto Meridional são áreas que devem ser preservadas, pois possuem uma rica comunidade de insetos aquáticos.

An inventory of macroinvertebrates conducted in the Contas River basin in Northeastern Brazil found 13 species of freshwater mollusks. Most of the community was represented by pulmonate gastropods, including Physa acuta, Drepanotrema anatinum, D. cimex, D. lucidum, Biomphalaria straminea?, Gundlachia radiata?, G. ticaga and Hebetancylus moricandi; the prosobranchs Pomacea archimedis?, Melanoides tuberculata and Littoridina sp. were also found. Bivalves were less diversified, represented only by Pisidium pulchellum? and Eupera simoni?. The taxonomic composition and the small size of many species reflect the intermittent condition of the basin. Additionally, the occurrence of shells of five terrestrial species (Helicina angulata, Gastrocopta pellucida hordeacella?, Beckianum beckianum, Succinea sp. and Systrophiidae gen. et sp. indet.) in the rivers reflects the occasional heavy rainfalls and floods in the region. The invasive gastropod M. tuberculata was the most abundant and widely distributed species. All 13 species were found in the lower course, in the Atlantic Forest region, and most, but not all, were recorded in the upper course, in the Caatinga region. The distribution and the occurrence of the bivalve species exclusively in the Atlantic Forest region indicate that the locally higher annual precipitation provides favorable conditions for the survival of these mollusks, such as a more stable hydroperiod. Treze espécies de moluscos de água doce foram encontradas em um inventário de macroinvertebrados realizado ao longo da bacia do Rio de Contas, no Nordeste do Brasil. A maioria da comunidade foi representada por gastrópodes pulmonados, como Physa acuta, Drepanotrema anatinum, D. cimex, D. lucidum, Biomphalaria straminea?, Gundlachia radiata?, G. ticaga e Hebetancylus moricandi, embora prosobrânquios, como Pomacea archimedis?, Melanoides tuberculata e Littoridina sp. também tenham sido encontrados. Bivalves foram menos diversificados, e foram representados por Pisidium pulchellum? e Eupera simoni?. A composição taxonômica e o pequeno tamanho alcançado por muitas espécies refletem a condição intermitente da bacia. Além disso, a ocorrência de conchas de cinco espécies terrestres (Helicina angulata, Gastrocopta pellucida hordeacella?, Beckianum beckianum, Succinea sp. e Systrophiidae gen. et sp. indet.) dentro dos rios reflete as fortes chuvas e inundações que ocorrem ocasionalmente na região. O gastrópode invasor M. tuberculata foi a espécie mais abundante e bem distribuída. Todas as espécies foram encontradas no curso inferior, na região da Mata Atlântica, e a maioria, mas não todas, foram registradas no curso superior, na região da Caatinga. Esta distribuição e a ocorrência das espécies de bivalves exclusivamente na região da Mata Atlântica indicam que a maior precipitação anual desta região fornece condições favoráveis para a sobrevivência destes moluscos, como um hidroperíodo mais estável.

This study presents an inventory of the genera of Odonata found in streams and artificial farm ponds in a montane region, with temperate climate, in southern Brazil. Differences in richness of lotic and lentic environments were also investigated. The diversity of odonate families and genera in southernmost Brazil is lower than in warmer, either tropical or subtropical, regions of the country. Nine genera are new records for the region and six genera had their geographical ranges extended to regions with temperate climate of the Neotropics. The overall richness and especially the overall abundance recorded in the studied area are possibly determined by the occurrence of numerous farm ponds because natural standing waters are scarce in the region. The presence of macrophytes in these artificial ponds allowed the establishment of a diversified odonatofauna, typical of lentic environments. Este estudo apresenta um inventário de gêneros de Odonata de riachos e reservatórios artificiais de uma região montanhosa de clima temperado no extremo sul do Brasil. Diferenças na riqueza de ambientes lóticos e lênticos também foram investigadas. A diversidade de famílias e gêneros de Odonata no extremo sul do Brasil é menor que em regiões mais quentes, tanto tropicais quanto subtropicais, do país. Nove gêneros são novos registros para a região e seis gêneros tiveram suas distribuições geográficas de ocorrência estendidas para áreas temperadas da região Neotropical. A riqueza e a abundância verificadas na área de estudo possivelmente foram determinadas pela ocorrência de numerosos reservatórios artificiais, pois áreas lênticas naturais são raras na região. A presença de macrófitas nestes reservatórios permitiu o estabelecimento de uma fauna de Odonata diversificada e típica de ambientes lênticos.

The study of the feeding ecology of Rhinodoras dorbignyi was conducted in three sites of the Ibicuí river, Rio Grande do Sul, Brazil, from December 1999 to January, 2003. The specimens were sampled bimonthly. The feeding spectrum was determined combining the frequency of the occurrence with the volume of each alimentary item, in order to obtain the feeding index (IAi). The spatial analysis was based on the diet and distribution of R. dorbignyi in the three sampling points, and also in their different biotopes. Temporal changes on diet and capture of the specimens were evaluated considering the seasons and the daily feeding rhythm. The intensity of spatial-temporal feeding intake was analyzed using the average stomach fullness. Significance level of 0.05 was used in the analyses. Ephemeroptera nymphs belonging to the family Polymitarcyidae represented the main feeding item (62.48%). The feeding spectrum of R. dorbignyi showed significant differences regarding sampling points, seasons, and biotopes. The species showed highest abundance in lotic environments, during the spring and summer and after sunset. No statistically significant results were observed with regard to spatial and temporal differences in feeding intake. Para a análise da ecologia alimentar de Rhinodoras dorbignyi, foram realizadas coletas bimestrais, durante o período de dezembro de 1999 a janeiro de 2002, em três pontos do rio Ibicuí, Rio Grande do Sul, Brasil. O espectro alimentar da espécie foi analisado por meio do índice de importância alimentar (IAi), avaliado pela combinação da freqüência de ocorrência e do volume de cada item alimentar. A análise espacial baseou-se na dieta e na distribuição da espécie nos três pontos de coleta e nos biótopos de cada um desses locais. Mudanças temporais na alimentação e na captura de exemplares foram verificadas sazonalmente e quanto ao ritmo circadiano. A intensidade espaço-temporal da tomada de alimento foi verificada por meio do grau de repleção médio; utilizou-se nível de significância de 0,05. Ninfas de efeméridas da família Polymitarcyidae constituíram o principal item alimentar de R. dorbignyi (62,48%). A espécie apresentou diferenças significantes no espectro alimentar em relação aos pontos de coleta, estações e ambientes. R. dorbignyi exibiu maior abundância em ambientes lóticos, na primavera e no verão e no período vespertino-noturno. Não foi observada significância para diferenças espaciais e temporais na captura de alimento.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES The aquatic ecosystems exhibit a diversity of biotic and abiotic characteristics, which together determine their functioning. In these environments, the macroinvertebrates community depend on the conditions found in the streams for their survival. Understanding these relationships is important to advance on knowledge of limnology. Thus, the goal of this thesis is to investigate aspects of the feeding and development of limnic macroinvertebrates relation to variation in resource quality and environment temperature. In chapter 1, we analyzed the food preference of the crustacean Aegla longirostri through standardized experiments with different plant and animal items. For aeglids, the microbial conditioning overlaps the initial leaf chemical quality. The animals prefer to consume the animal tissue, followed by conditioned leaves and lastly feed on unconditioned leaves, demonstrating preference for higher nutritional quality item. In chapter 2, we verified, under laboratory conditions, if temperature increase modifies leaf consumption, metabolites composition of the hepatopancreas and A. longirostri activity. Leaf consumption did not differ between studied temperatures (21 and 24º C). The amount of protein was higher at 21° C, and the amino acid and glycogen levels were higher at 24º C. At high temperatures the aeglids use, in hepatopancreas, energy from protein breakdown. Animals kept at 24º C showed a lower activity level, possibly a strategy to save energy. This study indicates that a future temperature increase of water streams, due to global warming, will impact the aeglids populations by changing their metabolism and behavior. In chapter 3, we investigated the relationship between temperature, adult size and growth rate of caddisflies. We conducted a field study to verify the emergent adult size at different temperatures using the altitudinal gradient as a predictor of temperature. Additionally, we measure under laboratory conditions the temperature dependence growth rates under three temperature regimes with Schizopelex festiva. We observed that the animals studied follow the temperature-size-rule, at higher temperatures the animals have a smaller body size (field experiment) and a higher growth rate (laboratory experiment). With the results of this thesis, we verified that the food resource and the temperature are factors that directly interfere in macroinvertebrates life of low orders streams. Thus, future warming of the streams freshwater due to global warming will modify their communities, and imbalances may occur in these ecosystems. Os ecossistemas aquáticos apresentam uma diversidade de características bióticas e abióticas, que juntas determinam o seu funcionamento. Nestes ambientes, a comunidade de macroinvertebrados é abundante e depende das condições encontradas nos riachos para sua sobrevivência. Entender estas relações é importante para avançarmos no conhecimento da limnologia. Assim, o objetivo desta tese é investigar aspectos da alimentação e desenvolvimento de macroinvertebrados límnicos frente à variação na qualidade do recurso e temperatura do ambiente. No capítulo 1 analisamos a preferência alimentar do crustáceo Aegla longirostri através de experimentos padronizados com diferentes itens de origem vegetal e animal. Para os eglídeos, o condicionamento microbiano sobrepõe-se à qualidade química inicial da folha. Os eglídeos escolheram consumir o tecido animal, seguido de folhas condicionadas e como última opção alimentam-se de folhas não condicionadas, demonstrando preferência pelo item de maior qualidade nutricional. No capítulo 2 verificamos, em condições laboratoriais, se o aumento da temperatura da água modifica o consumo de folhas, a composição de metabólitos no hepatopâncreas e a atividade de A. longirostri. O consumo de folhas não diferiu entre as temperaturas estudadas (21 e 24º C). A quantidade de proteína foi maior em 21° C e os níveis de aminoácidos e glicogênio foram maiores em 24º C. Em temperaturas elevadas os eglídeos utilizam, no hepatopâncreas, energia proveniente da quebra de proteínas. Os animais mantidos a 24º C apresentaram menor nível de atividade, possivelmente uma estratégia para economizar energia. Estes resultados indicam que um futuro aumento da temperatura dos riachos, efeito do aquecimento global, afetará as populações de eglídeos alterando seu metabolismo e comportamento. No capítulo 3 investigamos a relação entre temperatura, crescimento e tamanho de adultos tricópteros. Realizamos um estudo em campo para verificar o tamanho dos adultos emergentes em diferentes temperaturas, utilizando o gradiente altitudinal como preditor da temperatura. Para verificar o crescimento em diferentes temperaturas fizemos um estudo experimental em laboratório com o tricóptero Schizopelex festiva. Constatamos que os tricópteros estudados seguem a “temperature-size rule - TSR”, pois em temperaturas mais elevadas os animais apresentam um tamanho do corpo menor (experimento em campo) e uma taxa de crescimento maior (experimento em laboratório). Com os resultados desta tese verificamos que o recurso alimentar e a temperatura são fatores que interferem diretamente na vida dos macroinvertebrados nos riachos de pequena ordem. Assim, um futuro aquecimento das massas de águas doce, devido ao aquecimento global, irá modificar suas comunidades, podendo ocorrer desequilíbrios nestes ecossistemas.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES The objective of this study was to i) Analyze how the assemblages of larvae and adults of Elmidae respond to forest conversion in a subtropical area preserved in semideciduous Atlantic Forest; ii) Evaluate the influence of different buffers of riparian vegetation (more than 40 m wide to less than 5 m) and substrate types (sedimentary and organic), as well as their interaction in the community structure of Elmidae; iii) Model the potential distribution of Elmidae taxa in the extreme south of Brazil, in relation to climatic and landscape environmental predictors (topography, hydrology and land cover) using species distribution models (SDM). In addition, we estimated the similarity in the predicted distribution of the modeled taxa in order to investigate the niche similarity between the genera Elmidae and Macrelmis. Forest integrity was an important factor for the structuring of Elmidae communities, where in the converted areas the lowest abundances of elmidae individuals were found. The larvae and adult stages were affected by deforestation, just as the structure of the communities was distinct between deforested and forested areas. Width of riparian vegetation and type of substrate were also factors that influenced the structuring of communities. The results showed that the communities were influenced by marked differences in widths of riparian vegetation. Only the relative abundance of the genera of Elmidae and their stages of life were different between the wide widths of vegetation. On the other hand, the strong influence of the substrate type (organic and inorganic) on the structure of the neotropical macroinvertebrate community was corroborated. The potential distribution of species showed a relation of landscape and environmental factors of large scale with structures of genera and species of Macrelmis. Factors such as declivity, precipitation, and ecoregions were important for structuring the communities of genera and species, but we verified that there may be an interaction between the predictors on a regional and local scale. It is critical to understand the complex relationships between large-scale diversity patterns and the local ecological characteristics of species. The modeling techniques are an effective tool to indicate areas for future sampling efforts and thus to know the diversity of the Elmidae family in southern Brazil. Este estudo teve como objetivos, i) Analisar como as assembleias de larvas e adultos de Elmidae respondem a conversão florestal em uma área subtropical preservada de Floresta Atlântica semi-decídua; ii) Avaliar a influência de diferentes buffers de vegetação ripária (mais de 40 m de largura para menos de 5 m) e tipos de substrato (sedimentar e orgânico), bem como sua interação, na estrutura da comunidade de Elmidae; iii) Modelar a distribuição potencial de táxons de Elmidae no extremo sul do Brasil, em relação a preditores ambientais climáticos e paisagísticos (topografia, hidrologia e cobertura terrestre) usando modelos de distribuição de espécies (SDM). Além disso, estimamos a semelhança na distribuição prevista dos táxons modelados, a fim de investigar a semelhança de nicho entre os gêneros Elmidae e Macrelmis. A integridade florestal foi um importante fator para a estruturação das comunidades de Elmidae, onde em áreas convertidas foram encontradas as menores abundâncias de indivíduos de elmídeos. Os estágios larvais e adultos foram afetados pelo desmatamento, assim como a estrutura das comunidades foi distinta entre as áreas desmatadas e florestadas. Largura da vegetação ripária e tipo de substrato também foram fatores que influenciaram a estruturação das comunidades. Os resultados mostraram que as comunidades foram influenciadas por diferenças marcantes nas larguras de vegetação ripária. Somente a abundância relativa dos gêneros de Elmidae e seus estágios da vida foram diferentes entre os extremos de largura de vegetação. Por outro lado, a forte influência do tipo de substrato (orgânico e inorgânico) na estrutura da comunidade de macroinvertebrados neotropicais foi corroborada. A potencial distribuição de espécies mostrou relação de fatores paisagísticos e ambientais de larga escala com a estruturas de gêneros e espécies de Macrelmis. Fatores como declividade, precipitação, ecorregiões foram importantes para a estruturação das comunidades de gêneros e espécies, mas verificamos que pode haver uma interação entre os preditores em escala regional e local. É fundamental entender as relações complexas entre padrões de diversidade em larga escala e as características locais ecológicas das espécies. As técnicas de modelagem são uma ferramenta eficaz para indicar áreas para futuros esforços de amostragem e assim conhecer a diversidade da família Elmidae no sul do Brasil.

O enfoque deste trabalho se refere ao estudo de biogênicos fósseis calcários e silicosos, obtidos de três testemunhos de sondagem localizados no interior da Lagoa dos Patos. Os testemunhos estão inseridos ao longo de perfis sísmicos de alta resolução e são identificados como: Bojuru (Bo), Mostardas (Mo) e Palmares do Sul (Pa). A escolha desses locais amostrados foi feita com base em estudos de sísmica de alta resolução que identificou um sistema de vales incisos. No testemunho Mo, é apresentado um zoneamento qualitativo a partir dos biogênicos (moluscos, foraminíferos, ostracodes e diatomáceas) onde foram identificadas três zonas biogênicas. A zona I resultou no reconhecimento de um ambiente marinho a marinho mixohalino com influência marinha através da presença de diatomáceas. A zona II identificou um ambiente marinho associado a espécies marinhas a marinhas mixohalinas com a presença de todos os biogênicos inventariados somados a diatomáceas dulciaquícolas. E a zona III um ambiente marinho associado a espécies marinhas a marinhas mixohalinas onde ocorre uma redução dos biogênicos. No testemunho Pa, é feito um zoneamento quantitativo onde são identificados cinco grupos distintos de biogênicos constituídos por moluscos (G1), foraminíferos (G2), ostracodes (G3), equinodermas, cirrípedes e poríferos (G4) e diatomáceas (G5) Os táxons foram analisados e classificados de acordo com a abundância relativa, onde quatro zonas biogênicas (Zonas I, II, III e IV) são reconhecidas. Os biogênicos ocorrem de forma diferenciada ao longo de todo o testemunho, sendo a presença de diatomáceas observada em todos os intervalos amostrados enquanto os demais se concentram na porção basal. A Zona I (base do testemunho) apresenta os cinco grupos de biogênicos e é indicativa de ambiente marinho raso. A Zona II é caracterizada pela dominância de diatomáceas marinhas, indicando ambiente marinho. As diatomáceas de água doce são exclusivas da Zona III e indicam um ambiente fluvial com alguma influência marinha. E na Zona IV são observadas somente diatomáceas marinhas, marinhas a marinhas mixohalinas e mixohalinas, caracterizando um ambiente marinho. O conteúdo malacológico, identificado nos três testemunhos, englobam 19 táxons que foram examinados de forma detalhada sobre a ecologia e alguns aspectos tafonômicos. Os moluscos também são analisados quanto a sua identidade, diversidade e utilização para interpretações paleoambientais que identificaram duas assembleias distintas sendo uma mixohalina e outra mixohalina a marinha que preencheram os paleovales apontados pela sísmica. Este trabalho se insere no projeto sobre a Evolução Paleogeográfica da Planície Costeira do Rio Grande do Sul e o estudo dos biogênicos representa mais um dado no entendimento do quadro evolutivo da planície costeira gaúcha. The focus of this work is on the study of calcareous and siliceous biogenic fossils recovered from three stratigraphic cores obtained in the Patos Lagoon interior. The cores were named as Bojuru (Bo), Mostardas (Mo), and Palmares do Sul (Pa) according to the local drilling site, and the localization of three incised valley systems, which were previously collected and addressed in high-resolution seismic studies performed in the lagoon. A biostratigraphic zonation based on biogenic assemblage (mollusks, foraminifera, ostracoda, and diatoms) was presented in the qualitative analysis of core Mo. Three biogenic zones were recognized. Zone I is characterized by the exclusive presence of diatoms, which are indicative of a marine to marine-estuarine environment. Zone II is related to an estuarine environment associated with marine to marine-estuarine species of all biogenic groups, including freshwater diatoms. Zone III is characterized by the reduction of the biogenic taxa, and the presence of marine and marine-estuarine species, which are indicative of a marine environment. In core Pa, a quantitative analysis of biogenic assemblages reveled the presence of five distinct groups of mollusks (G1), foraminifera (G2), ostracoda (G3), echinoderms, cirripeds and poriferous (G4), and diatoms (G5) The biogenic taxa were analyzed and classified according to the percentage of individual species, and the interpretations were based on the relative abundances (%) of the most representative groups. Four biogenic zones (Zones I-IV) were recognized. The spatial distribution of the most representative taxa was variable through core. Diatom species occurred in all sampled intervals, while those other groups are concentrated in the basal part of the core. All biogenic groups occurring in the basal part of the core Pa are indicative of a shallow marine environment. Zone II is marked by the dominance of marine diatoms, which are indicative of a marine environment. Freshwater diatoms are exclusive of Zone III, and are indicative of a fluvial environment with some marine influence. In the upper part of the core, a marine environment is recognized and only marine to marine-estuarine diatoms were identified. The malacological content obtained from these three stratigraphic cores encompassed 19 mollusk taxa, which were analyzed in detail according to the ecological and taphonomic aspects. Their taxonomic identity and diversity, and the application of them in paleoenvironmental studies are also addressed. The results show that two incised valleys were infilled by estuarine and marine to estuarine assemblages. This work is inserted in a project about the Paleogeographic Evolution of the Rio Grande do Sul coastal plain, and the study of biogenic assemblages are used to expand the knowledge about the evolution of the present coastal plain.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES Mollusks can be a very frequent feeding item in the diet of many species of fishes inhabiting the Neotropical region. However, the possibility of malacofagous fishes act as important passive dispersors for native and exotic mollusks in rivers of this region is poorly documented. In this study, mollusks ability to survive of passing through the digestive system of Pimelodus pintado, Iheringichthys labrosus, Leporinus obtusidens and Rhinodoras dorbignyi, four species common in Southern Brazilian rivers, was evaluated. Three study methods, namely, intestinal content analysis, faecal content analysis and a laboratorial experiment, in which different mollusk taxa/morphotypes were offered to fishes, were used. Results obtained showed that the studied fish species apparently predate especially thinshelled morphotypes, although generally feeding on a variety of mollusk taxa/morphotypes. However, only thick-shelled morphotypes (Heleobia spp., Potamolithus spp., and Corbicula fluminea) were found alive in the fish rectum or feces. Individuals found alive not always survived more than 12 hours after having been placed on recipients containing water and oxygen. This result suggests that other factors should be involved in mollusks ability to survive. The absence of strong incisiform oral teeth in fish digestive tract is important for the survival of many mollusks, because their presence, such as in L. obtusidens, determinate the fragmentation of many shells. Thus, only P. pintado, I. labrosus and R. dorbignyi, which do not show this tooth type, could be considered as passive dispersers of some mollusk taxa, and of some Hidropsyche larvae and leeches in rivers of the Neotropical region. Possibly, these fish species were also involved in the invasion of many non-navigable streams in southern Brazil, by the Asiatic bivalve C. fluminea. Na região Neotropical, moluscos podem ser um item alimentar frequente na dieta de muitos peixes. Contudo, a possibilidade de peixes malacófagos atuarem como importantes dispersores passivos de moluscos nos rios da região não está bem documentada. Neste estudo, a capacidade de moluscos sobreviverem à passagem pelo trato digestório de Pimelodus pintado, Iheringichthys labrosus, Leporinus obtusidens e Rhinodoras dorbignyi, quatro espécies comuns nos rios da região sul do Brasil, foi avaliada. Três métodos de estudo foram utilizados: análise de conteúdo intestinal, análise de conteúdo fecal e experimento de oferta de diferentes táxons/morfotipos de moluscos em laboratório. Os resultados obtidos mostraram que, apesar de as espécies estudadas se alimentarem de grande variedade de moluscos, aparentemente, preferem predar moluscos com conchas finas. Contudo, apenas moluscos com concha espessa (Heleobia spp, Potamolithus spp e Corbicula fluminea) foram encontrados vivos no reto ou nas fezes. Destes, nem todos foram capazes de sobreviver por mais de 12 horas, após serem removidos do reto ou das fezes, e condicionados em recipientes contendo água e oxigênio. Isto sugere que outros fatores devem estar envolvidos na capacidade de sobrevivência dos moluscos. Adicionalmente, observou-se que a presença de fortes dentes orais incisivos em peixes como L. obtusidens, determinou a fragmentação de muitas conchas. Dessa forma, a ausência desse tipo de dente no trato digestório dos peixes é um fator importante para a sobrevivência de muitos moluscos. Na região Neotropical, apenas peixes sem dentes orais incisivos, como P. pintado, I. labrosus e R. dorbignyi podem ser considerados dispersores passivos de alguns táxons de moluscos e, ainda, de larvas de Hidropsyche e de sanguessugas. Possivelmente, estas três espécies também estão envolvidas na disseminação do bivalve asiático invasor, C. fluminea, em diversos riachos não navegáveis do sul do Brasil.

The additive partition diversity has been a promising method to analyze patterns of diversity in hierarchical studies. Streams are recognized for having a spatial structure hierarchically organized in increasing scales, ranging from places such as habitat, stretch, streams and the entire drainage system. The diversity and spatial distribution of mayfly nymphs communities were studied over four hierarchical spatial scales in Planalto Sul-rio-grandense (sampling units, substrates, streams and basin). Additionally, the influence of local environmental descriptors on the structure of the nymphs communities was tested. Samples were collected in 13 streams of two independent parts of the Planalto Sul-rio-grandense, in each stream were obtained 10 samples in falls five in stone substrate and five in leaves. The spatial distribution of mayfly nymphs showed structuring according to types of substrates sampled. The partitioning of diversity among the analyzed scales revealed that the major portion of beta diversity occurred between the sampling units and between the streams of the same dimension and a very small amount in the range of substrate. Thus, we assume that the fauna of aggregation in the smaller spatial scale was not due to substrate differences associated with rapid but the variation between rapids, reflecting the predominance of specific processes related to the availability of resources. We assume also that the nymphs of ephemeral not have barriers to the use at these substrate, which could actively move between the rapids of streams. In addition, the diversity that occurs between streams of the same part, can be attributed to local characteristics of each stream, such as slope, conductivity and current velocity. Finally, three environmental descriptors (altitude, slope, and dissolved oxygen) were important to structure the mayfly community at the streams of Planalto Sulriograndense. We conclude that the scales from rapids (sampling units) and between streams are scales that have the largest portion of the variability of the taxonomic composition showing to be more effective in assessing the spatial variation of mayfly nymphs communities. A partição aditiva da diversidade vem sendo um método promissor para analisar padrões de diversidade em estudos hierárquicos. Riachos são reconhecidos por apresentarem uma estrutura espacial organizada hierarquicamente, em escalas crescentes, variando desde locais, como habitat, trecho, riachos e toda a rede de drenagem. A diversidade e distribuição espacial das comunidades de ninfas de Ephemeroptera foram estudadas ao longo de quatro escalas espaciais hierárquicas no Planalto Sul-rio-grandense (unidades amostrais, substratos, riachos e bacias). Adicionalmente, a influência de descritores ambientais locais sobre a estrutura das comunidades das ninfas foi testada. As coletas foram realizadas em 13 riachos de duas bacias independentes do Planalto Sul-rio-grandense, em cada riacho foram obtidas 10 amostras em corredeiras, cinco em substrato de pedras e cinco em folhas. A distribuição espacial das ninfas de Ephemeroptera não mostrou estruturação segundo os tipos de substratos amostrados em corredeiras de riachos. A partição da diversidade entre as escalas analisadas revelou que a maior porção da diversidade beta ocorreu entre as unidades amostrais e entre os riachos da mesma bacia e uma porção muito pequena na escala de substrato e de bacia. Dessa forma, supomos que a agregação da fauna na menor escala espacial não foi devido à diferença de substrato, mas a variação entre corredeiras, refletindo a predominância de processos pontuais relacionados à disponibilidade de recursos. Supomos ainda, que as ninfas de efêmeros não encontram barreiras para a utilização desses substratos, as quais poderiam se deslocar ativamente entre as corredeiras de riachos. Adicionalmente, a diversidade que ocorre entre os riachos de uma mesma vertente, pode ser atribuída as características locais de cada riacho, tais como declividade, condutividade e velocidade da correnteza. Por fim, três descritores ambientais (altitude, declividade e oxigênio dissolvido) foram importantes para estrutura da comunidade de Ephemeroptera em riachos do Planalto Sul-riograndense. Concluímos que as escalas entre corredeiras (unidades amostrais) e entre riachos são escalas que detêm a maior porção da variabilidade da composição taxonômica evidenciando-se mais efetivas na avaliação da variação espacial das comunidades de ninfas de Ephemeroptera.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Wide spatial scales of analysis in studies conducted in natural wetlands tend to present the greatest contributions to the total diversity of aquatic macroinvertebrates, because they include macrovariables such as hydrographic basins and different types of aquatic systems. However, for agroecosystems such as rice fields (usually converted wetlands), the knowledge on the variation of these communities diversity along wide spatial scales is still scarce, therefore hindering conservationist actions. In this study, aquatic macroinvertebrate communities were sampled in January 2012 in irrigated rice fields from two geomorphological regions (Planície Costeira and Depressão Central), in southernmost Brazil (Rio Grande do Sul state). Four hierarchical spatial scales of analysis sample, rice field, rice area and geomorphological region were analyzed through the additive partitioning of diversity method. Estimated richness was similar between the studied geomorphological regions and rice areas. However, composition and, specially, dominant and indicator taxa varied between regions, mainly in the wider scales of analysis (regions and rice areas). Mean values of variables such as pH, dissolved oxygen, electrical conductivity and water temperature had greater variation between rice areas, influencing differences between communities in this scale. Differences in accumulated precipitation and mean air temperature between geomorphological regions had strong influence on communities variation. The additive partitioning method showed that the diversity variation was significantly higher than the expected by chance in among rice areas (β3) and among geomorphological regions (β4) scales. However, the percentual contribution of these scales for total diversity (γ) was lower than that of among rice fields scale (β2), due to the influence of differences in management practices and growth stages of the rice plant on macroinvertebrate communties. Although climatic differences strongly affected macroinvertebrate community structure from different geomorphological regions, the enviromental homogeneization and simplification promoted by this agroecosystem interfered in community diversity variation at regional scale. In general, differentiated management practices for each rice field were the most determinant factors for the diversity and special distribution of the aquatic macroinvertebrates communities. Em áreas úmidas naturais, escalas espaciais mais amplas de análise, que abarcam macrovariáveis como bacia hidrográfica e tipo de sistema aquático, tendem a apresentar as maiores contribuições para a diversidade total das comunidades aquáticas. Contudo, em agroecossistemas como arrozais (usualmente áreas úmidas convertidas), o conhecimento sobre a variação da diversidade destas comunidades ao longo de amplas escalas espaciais ainda é escasso e pouco compreendido, prejudicando ações conservacionistas. No presente estudo, comunidades de macroinvertebrados aquáticos foram amostrados, em janeiro de 2012, em arrozais irrigados de duas regiões geomorfológicas (Planície Costeira e Depressão Central), no extremo sul do Brasil (estado do Rio Grande do Sul). Quatro escalas espaciais hierarquizadas - em ordem crescente: amostra, arrozal, área e região geomorfológica - foram utilizadas para análise. A riqueza estimada foi similar entre regiões geomorfológicas e áreas estudadas, contudo a composição e, especialmente, os táxons dominantes e indicadores variaram entre as regiões, principalmente na maior escala. Valores médios de variáveis como pH, oxigênio dissolvido, condutividade elétrica e temperatura da água variaram mais entre as áreas de estudo, influenciando diferenças entre as comunidades nesta escala. Diferenças nos valores de precipitação acumulada e temperatura média do ar nas duas regiões tiveram forte influência nas variações das comunidades. O método da partição aditiva mostrou que a variação da diversidade foi significativamente maior do que o esperado ao acaso nas escalas entre áreas de arrozais (β3) e entre regiões geomorfológicas (β4). Contudo, a contribuição percentual de ambas para a diversidade total observada (γ) foi menor do o que a de escala entre arrozais (β2), devido à influência de diferenças de técnicas de manejo e estágios de crescimento dos arrozais sobre as comunidades de macroinvertebrados. Embora as diferenças climáticas das regiões afetem intensamente a estrutura das comunidades de macroinvetebrados em arrozais de diferentes regiões geomorfológicas, a homogeneização e simplificação ambiental desse agroecossistema interferiu na variação da diversidade das comunidades em escala regional. De forma geral, as práticas de manejo diferenciadas de cada arrozal foram os fatores mais determinantes para a diversidade e distribuição espacial das comunidades de macroinvertebrados aquáticos.