Scinax tropicalia Novaes-E-Fagundes & Araujo-Vieira & Entiauspe-Neto & Roberto & Orrico & Solé & Haddad & Loebmann 2021, sp. nov

Scinax tropicalia sp. nov. Scinax x-signatus — Dias et al. (2014a: Table 1), Mira-Mendes et al. (2018: Table 1, Fig. 4). Scinax cf. x-signatus — Dias et al. (2014b: Table 2), Rojas-Padilla et al. (in press: Table 1, Fig. 4G, Appendix 1). Scinax sp. aff. hayii — Roberto & Loebmann (2016: 136, 146, Tables 1 and 3, Supplementary Table 1 and Fig. 11), Araujo-Vieira et al. (2020: 18). Generic and phylogenetic placements. The new species is assigned to Scinax based on the three synapomorphies of the genus: webbing between toes I and II not extending beyond the subarticular tubercle of Toe I; origin of the m. pectoralis abdominalis through well-defined tendons; and m. pectoralis abdominalis overlapping the m. obliquus externus (da Silva 1998; Faivovich 2002; Faivovich et al. 2005). The new species is a member of the S. ruber clade (Faivovich 2002; Faivovich et al. 2005) by having a combination of pectoral fold present, external vocal sac, and medial slip of the m. extensor digitorum comunis longus of the hand with a single insertion on the dorsum of metacarpal IV, which differentiate adults of species of the S. ruber clade from all those of the S. catharinae clade. Holotype. MZUESC 20440, adult male, campus of the Universidade Estadual de Santa Cruz (UESC), municipality of Ilhéus, state of Bahia, Brazil [datum WGS84; -14.795694°, -39.172645°, about 30 m above sea level (a.s.l.)], collected 18 July 2018 by G. Novaes-e-Fagundes. Paratypes. A total of 65 adults (47 males and 18 females). Nineteen specimens from the type locality. MZU- ESC 20420, 20436, 20438 (females), 20324, 20413–20419, 20421–20425, 20437, 20439, CFBH 44691 (males), collected on different dates between 25 March and 17 July 2018 by G. Novaes-e-Fagundes. Two specimens from the state of Ceará, Brazil. CFBH 25423, 25425 (males) from Parque das Trilhas (-4.265833°, -38.935278°), Serra de Baturité, municipality of Guaramiranga, collected 23 January 2009 by D. Loebmann. Forty-four specimens from other localities in the state of Bahia, Brazil. MHNJCH 1258, 1260, 1373, 1522 (females), 1257, 1418 (males), Morro do Mara (-13.899639°, -39.952515°), between municipalities of Jequié and Jitaúna, collected on different dates in August, October, and December 2018 and April 2019 by Deivson F. O. Bastos. MZUESC 9176 (male), RPPN Fazenda Capit„o (-14.323356°, -39.076132°), municipality of Itacaré, collected 29 November 2010 by Tadeu Medeiros. MZUESC 10214 (male), Fazenda Santo Antônio, municipality of Ibicaraí (-14.857932°, -39.59182°), collected 4 February 2012, unknown collector. MZUESC 10330 (male), Reserva Serra Bonita (-15.383°, -39.550°), municipality of Camacan, collected 1 December 2010 by Iuri R. Dias. MZUESC 17933 (male), Parque Estadual Serra do Conduru (-14.493444°, -39.135833°), municipality of Uruçuca, collected 16 November 2016 by Débora Cruz. MZUESC 20449, 20453 (females), 20450 (male), Fazenda Bonfim (-14.610685°, -39.356982°), municipality of Uruçuca, collected 29 October 2018 by V. G. D. Orrico, Omar Rojas-Padilla, and Vinícius Q. Menezes. MZUESC 20193–20195, 20197–20201, (males), 20427 (female), Ilha Pequena (-13.939611°, -39.015778°), MZUESC 20208, 20209, 20228 (males), 20243 (female), CFBH 44689, 44690 (males), Ilha Grande (-13.912077°, -39.002759°), municipality of Camamu, collected on different dates in November 2016, 2017, March and May 2017, and July 2018 by G. Novaes-e-Fagundes, Leildo Carilo-Filho, and César Alexandre. MZUESC 20311 (male), Piracanga (-14.215941°, -38.99201°), municipality of Maraú, collected 20 April 2018 by G. Novaese-Fagundes. MZUESC 20408, 20409 (females), 20410 (male), CFBH 44693 (male), Parque Nacional Serra das Lontras (-15.17961°, -39.34554°), municipality of Arataca, collected 19 and 21 February 2018 and 11 and 12 April 2018 by Omar Rojas-Padilla. MZUESC 20411 (female), 20412 (male), CFBH 44692 (female), Estaç„o Ecológica Wenceslau Guimar„es (-13.595717°, -39.719767°), municipality of Wenceslau Guimar„es, collected 29 and 30 April 2018 by Marcos Vila-Nova. MZUESC 20433, 20435 (males), Fazenda Bom Pastor (-14.683556°, -39.1714°), municipality of Ilhéus, collected 8 July 2018 by Renan N. Costa. MZUESC 16647, 20443, 20444 (females), 20445, 20446 (males), Fazenda Provis„o (-14.650479°, -39.21483°), municipality of Ilhéus, collected 7 August 2016 by un-known collector or 18 July 2018 by Iuri R. Dias and Caio V. Mira-Mendes, MZUESC 21756 (male), Serra da Jibóia (-12.871967°, -39.48164°), municipality of Elísio Medrado, collected between 23 February and 3 March 2015 by Iuri R. Dias. Referred specimens. Three adult specimens. CFBH 27973, route to Piraí do Norte, municipality of Gandu, state of Bahia, Brazil, collected 25 January 2011 by Tuliana Brunes, Michele Gonçalves, and Nelson Rodrigues. CFBH 25880, Parque das Trilhas, Serra de Baturité, municipality of Guaramiranga, state of Ceará, Brazil, collected 21 March 2010 by I. J. Roberto and Paulo T. Brito. MNRJ 55443, Sítio Horizonte Belo, Serra de Baturité, municipality of Pacoti, state of Ceará collected 31 January 2007 by I. J. Roberto. Description of the holotype. Adult male (SVL = 34.8 mm) in a good state of preservation, with a muscle sample tissue (TUESC 1411) removed from the right shank and preserved in 96% ethanol and frozen prior to fixing the voucher specimen in formalin (Fig. 1). Head as wide as long, HL 32.8%, and HW 33.1% of SVL. Snout slightly protruding in profile (Fig. 2A), nearly rounded in dorsal view (Fig. 2B). Nostrils dorsolateral, elliptical, protruded; IND 22.9% of HW. Canthus rostralis marked and convex. Loreal region concave. Eyes large and protuberant, ED 36.3% of HW, and 12.0% of SVL. Pupil horizontal and subelliptical. Palpebral membrane translucent, not reticulat-ed, its margin with a thin dark rim. Tympanum distinct, round, small, TD 40.4% of ED. Tympanic annulus rounded, with upper portion hidden by the supratympanic fold. Supratympanic fold barely evident, from the upper portion of the tympanum to the insertion of the arm. Tongue ovoid, free laterally and posteriorly, shallowly notched posteriorly. Vomerine teeth in two barely separated transverse series, each bearing five (right) and six (left) teeth, between choanae. Choanae oval. Vocal slits present, nearly parallel to mandible. Vocal sac subgular, median, ventrally not reaching pectoral region and not occupying space between head and body, with a slight medial constriction in the posterior portion, which gives it a bilobate shape when inflated and deflated (Figs. 1B and 2C). Pectoral fold present, with pre- and postaxillar elements. Axillary membrane absent. Forelimbs not hypertrophied, upper arm thinner than forearm, hands proportionally large, HAL 30.8% of SVL. Small, round, ulnar tubercles on ventrolateral margin of forearms. Fingers not swelled (Fig. 3A, B). Relative finger length II Cloacal opening directed posteriorly at upper level of thighs. Skin texture areolate on abdomen, flanks, and posterior and ventral surface of thighs; granular to tubercular on region between tympanum and arm insertion, lateral margin of forearms and tarsi, subcloacal region, and heels; shagreened to granular on dorsum of head, trunk, and limbs; smooth on throat, groin, and hidden parts of limbs. There is no evidence of any thickened or glandular area in pectoral region and forelimbs. Measurements (mm). SVL 34.8; HL 11.4; HW 11.5; SL 6.1; IND 2.6; IOD 7.6; ED 4.2; EN 4.0; TD 1.7; HAL 10.7; FL 15.5; TL 18.3; 3FD 1.9; 4TD 1.7. Coloration in life. Dorsal color pattern brown with small, irregular, dark brown blotches and two larger longitudinal ones, extending from the posterior corner of the eyes to the sacral region (Fig. 5). Several scattered light brown or yellow small spots present on dorsum. On dorsum of head, at the level of eyes, a dark brown fragmented marking resembling the outline of a duck´s foot (Fig. 5A, B). Dorsolateral, longitudinal, dark brown blotches from the posterior corner of the eyes, through upper margin of tympanum, to the anterior portion of the flanks, near the axillae. Dark brown blotches on upper lip, near the infra-orbital margin of the eye, and on snout covering the nostrils. Canthus rostralis covered by dark brown irregular blotches. Iris bronze with black thin reticulations, golden thin halo bordering the pupil, short vertical black marking below the posterior fold of the pupil, and horizontal black band in its central portion. Dark brown transverse bars on dorsal surfaces of fingers, toes, forelimbs, and thighs, and large blotches on shanks and tarsus. Nuptial pads light-colored. Discs brown dorsally and translucent bluish gray ventrally. Toe webbing covered by brown melanophores. Ulnar and tarsal tubercles light brown or gray. White bones. When calling at night, the holotype presented a general brighter and yellow coloration than that on the inactivity call period described above (compare Fig. 5A, B). The following description is based on the freshly euthanized individual (Fig. 5 C–E). Chest and belly yellow with scattered small brown spots. Throat orange yellow, also finely pigmented with brown spots on anterior portion. Thighs light brown pigmented with darker brown spots. Axillae, inguinal region, and hidden surfaces of thighs, shanks, and tarsi light yellowish green, with medium to large size, rounded and irregular, black blotches. Flanks light yellow. Palms and soles brown. Coloration in preservative. Coloration pattern is similar but paler than that of the living specimen. Light yellow or green coloration on flanks, throat, chest, belly, axillae, inguinal region, and hidden surfaces of thighs, shanks, and tarsi faded and became light beige or cream white after two years in ethanol 70%. Iris coloration became pale blue. Variation. Morphometric variation of specimens of the type series is in Table 1. In dorsal view (Fig. 6A), snout rounded, nearly rounded, or semi-circular; some of the rounded or nearly rounded snouts are also slightly mucronate or slightly truncate. In lateral view, snout rounded or slightly protruding. Vomerine teeth in two fairly separated, barely separated or juxtaposed transverse or oblique series. Number of vomerine teeth ranges between 3–9 on right and 4–8 on left processes. Tongue shape ovoid, lanceolate (MZUESC 20410), or cordiform (MZUESC 20422). Tongue texture granular or smooth. The degree of the medial constriction in males’ vocal sacs varies from slight to conspicuously evident among specimens (Fig. 6B). Overall skin texture similar to holotype, with some variation concerning the development and density of dorsal granules and tubercles, which are more (e.g., MZUESC 10214) or less (e.g., MZUESC 20417) protuberant in some specimens. Ulnar and tarsal tubercles protuberant (e.g., MHNJCH 1257, MZUESC 17933, 20412, 20450) or inconspicuous (e.g., MZUESC 20194, 20417, 20421). In preservative, dorsal color pattern varies from a gray to brown background, with small, irregular, dark blotches and a pair of continuous or discontinuous longitudinal ones (Fig. 6A). In most specimens, both or, at least, one of the longitudinal blotches extending continuously from the post-orbital to sacral regions; both blotches are discontinu-ous in some specimens; when discontinuous, the anterior portion is longer than the posterior one. Male specimens from Bahia usually have longer, continuous, or discontinuous dorsal blotches, whereas specimens from Ceará have shorter and discontinuous dorsal blotches. Dorsal longitudinal blotches also can vary in width and outline, being straight or sinuous, with lateral projections (e.g., MHNJCH 1257) and coalescing with the interocular mark in some specimens. When present, small light spots on dorsum vary in number and size and are usually coincident with the skin granules and tubercles. Other dark brown smaller blotches on dorsum are present in some specimens (e.g., MZUESC 20437, 20450). Interocular marking can be inverted triangle, trapezium, pentagon (MZUESC 20438), T-shaped (MHNJCH 1257, MZUESC 20409), V-shaped (MZUESC 20439), W-shaped (MZUESC 10214), or irregular (MZUESC 20193). Most of inverted triangle and trapezium markings are anteriorly mucronate, resembling the outline of a duck’s foot; the mucronate projection’s length varies from short (not surpassing the anterior edge of the eyes) to long (almost reaching the nostrils). Posterior projection of the triangle, T-, and V-shaped markings varies in length, reaching the level of tympanum, arms insertion, or posterior edge of eyes. Interocular markings sometimes coalesce with one or both dorsal longitudinal blotches. Canthal dark stripe is present in almost all specimens but can be inconspicuous (MZUESC 10214, 20450) in some individuals. Dorsolateral and post-orbital longitudinal blotches are poorly defined in one specimen (MZUESC 20450). Infra-orbital blotch is inconspicuous or diffuse in three specimens (MZUESC 10214, 20419, 20450). Dark brown oblique bars on dorsal surface of shanks (e.g., MZUESC 20234, 20408, 20433) and transversal bars on tarsi (e.g., MZUESC 20410, 20414, 20435) are present in some specimens. In some individuals, dark coloration predominates on posterior portion of thighs, with small light blotches generally present (e.g., MZUESC 20414, 20433, 20436, 20443). Palms, soles, gular region, chest, and belly cream white to light beige, immaculate, or finely or conspicuously covered with brown pigmented spots (Fig. 6B). Mental region finely pigmented. Gular region (vocal sac) lacks pigmentation in some individuals. Chest and belly conspicuously pigmented in most specimens (e.g., MZUESC 20412, 20435), finely pigmented (MZUESC 20421), or immaculate in some specimens (CFBH 25423, 25425, MZUESC 20437). Webbing formulae in males varies as follows: I (21/2 –2 -)–(21/2 –2 -) II (11/2 –1)–(2 + –2 -) III (11/2 –1)–(21/2 –2) IV (21/2 –2 -)–(11/2 –1) V. Females are larger than males (Fig. 6; Table 1) and lack vocal slits, vocal sacs, and nuptial pads. Dorsal color pattern varies from gray to brown, being usually grayish than males—that is specially noticed when they are in amplexus. Gular region, chest, and belly are white or light gray, conspicuously covered with brown spots. Axillae, inguinal region, and hidden surfaces of thighs and shanks have light blue or purple background. Webbing is slightly more developed in females than males (with exception of webbing between toes II and III) and varies as follows: I (2 + –2 -)–(2 + –2) II (2–1)–(2–2 -) III (1 + –1)–(2 + –2) IV (2 + –2)–(1 + –1) V. In life, paratypes’ dorsal color pattern is generally similar to that of holotype but varies from gray to brown, with light to dark blotches (Fig. 7). Throat region and abdomen of males vary from light yellow to beige (Fig. 7 A–C), while in females they are whitish (Fig. 7D). Axillae, inguinal region, and hidden surfaces of hindlimbs are colored with light tones of blue, green, yellowish-green, and dark brown to black blotches; flanks are light yellow (Fig. 7 A–C). Females are usually more grayish than males (Fig. 7D), and background coloration of axillae, inguinal region, and hidden surfaces of hindlimbs are white, light blue, or light purple. There are no photos of living paratype specimens (CFBH 25423, 25425) from municipality of Guaramiranga, state of Ceará. We included some photos of unvouchered specimens from Pacoti and Guaramiranga in Fig. 8. In general, the pattern of coloration of these specimens agrees with that of paratypes, as described above. Bioacoustic repertoire. The vocal repertoire of Scinax tropicalia is composed of at least three types of calls. The advertisement call (sensu Wells 2007) is the most commonly emitted by males (Fig. 9, Table 3). It consists of a single stereotyped pulsed short note (i.e., amplitude-modulated; 0.114 –0.310 s) emitted repeatedly at irregular intervals (0.291 –1.336 s), not forming a coherent series (Fig. 9, Table 3). Notes begin with one or two initial pulses with lower amplitude frequency and duration than the following pulses; from the second or third pulse, the maximum amplitude is similar (Figs. 9, 10). The number of pulses per note ranges from 8–20, which are emitted at a rate of 56–71 pulses/s with a pulse period of 0.014 –0.016 s (Table 3). The pulse with maximum amplitude frequency is at the middle or at the ending of the note (see “Note shape” column in Table 3), and in the second pulse in one single call. Pulses are amplitude-modulated with five pulse sub-units of discrete amplitude, except for the first pulse with fewer, inconspicuous sub-units (Figs. 9, 10). Pulses increase in amplitude from beginning to the end, with the pulse sub-unit of maximum amplitude at the end of the pulse (Figs. 9B, 10). Note energy is distributed through a broad spectrum of frequencies, from 1.51–1.77 kHz at the bottom (frequency 5%) up to 3.06–5.12 kHz at the top (frequency 95%), comprising a mean bandwidth of 2.44 kHz (Table 3). The frequency 75% is the most variable spectral parameter ranging from 1.76–4.56 kHz. The dominant frequency varies between 1.59–1.85 kHz (Figs. 9, 10, Table 3), near or equal to the frequency 25% (1.59–1.89 kHz). A second energy peak around 3.0–4.0 kHz that corresponds to the frequency 75%