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The red alga Bangia maxima, in addition to its large size (up to 35 cm long 3 6 mm in diameter), was found in this study to be distinguishable from other species of Bangia by the character of mature filament apices containing elongate, separated vegetative cells. The phylogenetic position of B. maxima was resolved using both the rbcL and nuclear small subunit rRNA (nSSU rRNA) gene sequences and the genetic variation within a population was studied using an intersimple sequence repeat (ISSR) polymerase chain reaction (PCR)-based DNA fingerprint analysis. In phylogenetic analyses of the plastid rbcL gene region and nSSU rRNA, B. maxima grouped with local populations of concurrently collected B. vermicularis and B. fuscopurpurea as well as other collections of B. fuscopurpurea from California in a clade of predominantly eastern Pacific isolates. Banding patterns from 13 male filaments from seven littoral boulders for five ISSR primers were used to develop both band presence or absence and distance matrices (using the Dice coefficient). Banding patterns of B. maxima isolates were highly polymorphic among different boulders but consistent among individuals from the same boulder, as demonstrated by multivariate analyses (UPGMA, principal coordinates analysis). UPGMA analysis also indicated a limited genetic transfer among boulders. These results help in clarifying the population genetics of B. maxima and further understanding of genetic diversity within the Bangiales. [ABSTRACT FROM AUTHOR]

Previous phylogenetic studies of the Rhodophyta have provided a framework for understanding red algal phylogeny, but there still exists the need for a comprehensive analysis using a broad sampling of taxa and sufficient phylogenetic information to clearly define the major lineages. In this study, we determined 48 sequences of the PSI P700 chl a apoprotein A1 ( psaA) and rbcL coding regions and established a robust red algal phylogeny to identify the major clades. The tree included most of the lineages of the Bangiophyceae (25 genera, 48 taxa). Seven well-supported lineages were identified with this analysis with the Cyanidiales having the earliest divergence and being distinct from the remaining taxa; i.e. the Porphyridiales 1–3, Bangiales, Florideophyceae, and Compsopogonales. We also analyzed data sets with fewer taxa but using seven proteins or the DNA sequence from nine genes to resolve inter-clade relationships. Based on all of these analyses, we propose that the Rhodophyta contains two new subphyla, the Cyanidiophytina with a single class, the Cyanidiophyceae, and the Rhodophytina with six classes, the Bangiophyceae, Compsopogonophyceae, Florideophyceae, Porphyridiophyceae classis nov. (which contains Porphyridium, Flintiella, and Erythrolobus), Rhodellophyceae, and Stylonematophyceae classis nov. (which contains Stylonema, Bangiopsis, Chroodactylon, Chroothece, Purpureofilum, Rhodosorus, Rhodospora, and Rufusia). We also describe a new order, Rhodellales, and a new family, Rhodellaceae (with Rhodella, Dixoniella, and Glaucosphaera). [ABSTRACT FROM AUTHOR]

Representatives of the freshwater red algal family Thoreaceae were studied to resolve their taxonomic and phylogenetic status. Three specimens of Nemalionopsis and five collections of Thorea were examined for pit plug ultrastructure and analyzed for the sequences of the genes coding for the large subunit of RUBISCO (rbc L) and the small subunit of rRNA (18S rRNA). The phylogenetic trees generated from the two genes, and a combined tree all showed the Thoreaceae to be contained in a well-supported monophyletic clade that is separate from the other two families currently classified in the Batrachospermales, the Batrachospermaceae and the Lemaneaceae. In addition, secondary structure elements of the 18S rRNA gene were observed at positions 650 and 1145 (Escherichia coli numbering system) that are not present in other members of the Rhodophyta. The pit plugs of the gametophytic and chantransia stages of the Thoreaceae contain two cap layers, the outer one of which is typically plate-like, though occasionally inflated ones have been seen. No pit plug cap membrane has been observed. These findings indicate the Thoreaceae has been misclassified in the Batrachospermales and should be placed in its own order, the Thoreales. This order is characterized by having freshwater representatives with multiaxial gametophytes, a uniaxial chantransia stage, and pit plugs with two cap layers, the outer one of which is usually plate-like. [ABSTRACT FROM AUTHOR]

SUMMARYThe development and release of the unique vegetative propagules of the freshwater encrusting alga Hildenbrandia angolensis Welwitsch ex West et West, gemmae, were studied using several different microscopic and histochemical techniques. In addition, the seasonality of gemma production was monitored bimonthly over a 12-month period in two spring-fed streams in Texas, USA. Gemmae differentiate within the thallus and are subsequently released from the surface of the crust. Release of the gemmae most likely occurs by digestion of surrounding cells, as suggested by the presence of starch granules and lipid globules in the region between the released gemma and the thallus. The initial separation of the gemmae from the thallus occurs from the sides of the gemma or the bottom, or possibly simultaneously. Contrary to previous studies, we have observed that gemma production occurs endogenously within the thallus of freshwater Hildenbrandia, rather than on the surface of the crust in raised structures. Histochemical tests and electron microscopic examination indicate that the cells of the gemmae contain a large amount of floridean starch. The starch granules frequently form rings surrounding the nuclei of both gemma and thallus cells; a feature infrequently reported for florideophyte red algae. Our seasonality investigations indicate that large fluctuations in gemma production occur over 1 year, but at least some gemma production continues year-round in the streams examined. [ABSTRACT FROM AUTHOR]

Analyzes unialgal cultures and field collections of the rhodophyte Balbiana investiens Sirodot in terms of their morphology, ultrastructure and the DNA sequences of the genes coding for the large subunit of ribulose-1,5-biphosphate carboxylase/oxygenase and 18S ribosomal RNA. Distinguishing features of the species; Identical sequences for all regions of DNA analyzed by the two specimens of Balbiana from England and Germany.

Fifteen populations of the widespread freshwater red alga Batrachospermum gelatinosum (L.) De Candole were sampled throughout the geographic range in North America from central Alabama, U.S.A. (33°N) to Ellesmere Island, Nrothwest Terriotories (NWT), Canada (80°N). Analysis of ribosomal DNA internal transcribed spacer (TTS) 1 and 2 sequences yielded a parsimony tree with a large polytomy consisting of most populatins plus a branch with one Nava Scotia and two NWT populations. The nucleotide vatioation, both within the polytomy and within the branch, was small (<1%). The sequence divergence between the branch and polytomy was 3%. The lengths of the ITS 1 and 2 sequences of B. gelatinosum, 216-229 and 448-458 base pairs, respectively, fall within the very broad ranges reported for other red algae. The cluster analysis of 11 morphometric characteristics revealed three groupings of populations, partly based on geographic distribution. All tundra, eastern boreal forest, and Midwestern hemlock-hardwood populations were in one grouping, whereas the deciduous forestm coastal plain, and eastern hemlock-hardwood populations were in a second. However, one deciduous forest population from Rhode Island, U.S.A. was unassociated. There was considerable overlap in morphometric characteristics among the three groupings. Based on this fact and the relatively small nucleotide variation in ITS sequences, we conclude that B. gelatinosum is a morphologically variable and geographically wide-spread species that is a valid taxonomic entity. [ABSTRACT FROM AUTHOR]

Twenty-one populations of Batrachospermum section Turfosa from North America were compared to nine type and two historically important specimens using multivariate morphometrics and image analysis. The protologues of six other infrageneric taxa were also compared. From this analysis, six species are recognized worldwide: B. desikacharyi Sankaran, B. gombakense Kumano et Ratnasabapathy, B. keratophytum Bory de Saint-Vincent [syn. B. vagum var. keratophytum (Bory de Saint-Vincent) Sirodot, B. gulbenkianum Reis, and B. suevorum Kützing nom. illeg.], B. sinense Jao, B. turfosum Bory de Saint-Vincent [syn. B. vagum (Roth) C. Agardh and B. vagum var. undulato-pedicellatum Kumano et Watanabe], and B. vogesiacum F. G. Schultz ex Skuja [syn. B. vagum var. flagelliforme Sirodot, B. flagelliforme (Sirodot) Necchi]. These species are distinguished on the basis of carposporophyte-bearing branch cortication, secondary fascicle development, monoecy or dioecy, presence of spermatangia on involucral filaments and monosporangia, and dimensions of trichogynes and carposporangia. Peripheral cortication has been previously used to separate species in this section, but we observed that this feature is quite widespread in the section. Presence of indeterminate gonimoblast filaments has been reported for some taxa in section Turfosa, but not such structures were seen in any of the specimen examined. Only B. keratophytum has been collected in North America, ranging from southwestern Greenland (64° N) to Louisiana (30° N). [ABSTRACT FROM AUTHOR]

Six populations of Batrachospermum section Setacea from North America were compared to eight type specimens using multivariate morphometrics and image analysis. From this analysis, four species in this section were distinguished worldwide: B. attrum (Hudson) Harvey [syn.B. gallaei Sirodol, B. orthostichum Skuja, B. sertularina (Bory) Bory]; B. diatyches Entwisle; B. androinvolucrum sp. nov.; and B. puiggarianum Grunow in Wittrock et Nordstedt (syn. B. angolense Welwitsch ex West et West, B. nigrescenes Welwitsch ex West et West). Two of these species were found in North America: B. attrum in California and Texas and B. androinvolucrum in British Columbia, Washington State, and Alabama. The new species, B. androinvolucrum, is distinguished by having spermatangia restricted to one-celled involucral bracts of the corpogonial branch [ABSTRACT FROM AUTHOR]

Multivariate morphometrics and image analysis were used to determine the number of well-delineated infrageneric taxa 0fSirodotia in North America. Three groupings were distinguished from 25 populations examined from Newfoundland and Quebec in the north to central Mexico in the south. These groupings were statistically related to 10 type specimens, and the following species were recognized: Sirodotia huillensis (Welwitsch ex W. et G. 3. West) Skuja (syn. S. ateleia Skuja), S. suecica Kylin (syn. S. acuminata Skuja ex Flint and S. fennica Skuja), and S. tenuilssima (Collins) Skuja ex Flint. These speies are differentiated on the basis of whorl shape and appressed; S. huillensis and S. tenuissima, truncated apex and separated), the density of spermatangia (S. huillensis, dense clusters; S. suecica and S. tenuissima, sparsely aggregated), and the mode of germination of the gonimoblast initial (S. suecica and S. tenuissima, from the nonprotuberant side of the fertilized carpogonium; S. huillensis from the protuberant side). Sirodotia huillensis was found only in the desert-chaparral, whereas S. succica and S. tenuissima occurred from southtemperate to boreal regions in cool (temperature 8-18°C), low ion (specific conductance 10-99 μ°cm[SUP-1], and mildly acidic to neutral (pH 5.7-7.3) waters. [ABSTRACT FROM AUTHOR]

Twenty-five freshwater populations of Ceramiales were collected in North America, 24 of which were from the tropical rainforest region of Central America and the Caribbean. The streams tended to be moderate in mean current velocity (&Xbar; = 23.3 cm·s[sup-1]) and maximum width (X = 6.3 m) but high in temperature (&Xbar;= 23.1°C), pH (&Xbar; 7.9), and specific conductance (&Xbar; = 320 μS·cm[sup-1] Three Bostrychia species were restricted to the Caribbean islands: B. moritziana (Sonder ex Kütz) J. Ag. (syn. B. cornigera Mont. and B. radicans f. moniliforme Post). with ecorticate indeterminate axes. monosiphonous ultimate branches, and cladohaptera; B. radicans (Mont.) Mont. (syn. B. leprieurii Mont. and B. rivularis Harv.), with ecorticate and polysiphonous axes throughout and cladohaptera; and B. tenella (Lamour.) J. Ag. with core, cate indeterminate axes, monosiphonous ultimate branches, and peripherohaptera. Ballia prieurii Kütz. was found in Belize and Costa Rica and u, as characterized by rebranched determinate laterals, opposite branching, and long apical cells (&Xbar; = 61 μm) and axial cells (X 43 μm) Caloglossa leprieurri (Mont.) J. Ag. was localiud in Puerto Rico while, C. ogasawaerensis Okam. Was collected only in Costa Rica. The two species were separated by site of branching (midrib vs. margin) and blade width 384 us 861 μm) Polysiphonia subtilissima Mont from Florida and Jamaica had four pericentral cells, no cortication, rhizoids arising from pericentral cells, and branches initiated at trichoblast scars. [ABSTRACT FROM AUTHOR]

Multivariate morphometrics and image analysis were used to determient he number of well-distinguished infrageneric taxa in the section Contorta of the freshwater red algal genus Batrachospermum in North America. Five groupings were distinguished from 29 populations examined from New Mexico to costa Rica. These entities were statistically related to 12 type specimens reported from or similar to North American populations. The following taxa were recognized: B. ambiguum Montagne (syn. B. bicudoi Necchi and B. basilare Fling et Skuja) B. globosporum Israelson (syn. B. cipoense Kumano et Necchi and B. Jolyi Necchi), B. intortum Jao, B. louisianae Skuja and B. Procarpum Skuja var. americanum var. nov. The new variety differs from the nominate variety in having significantly larger whorls and smaller carpogonia. Batrachospermum ambiguum, B. louisianae, and B. procarpum var. americanum occur in low ion waters (10-187 μS·cm[SUP-1]), whereas B. intortum and B. globosporum are found in h igh ion waters (260-1760 μS·cm[SUP-1]). Detailed descriptions and a key to the five taxa are given. [ABSTRACT FROM AUTHOR]

Polysiphonia subtilissima Mont. is reported for the first time from a freshwater environment. The presence of four pericentral cells, subdichotomous branching, apical trichoblasts and rhizoids arising from pericentral cells combined with a lack of cortication and reproductive cells is consistent with marine populations of this species. The range of filament length is 1.4-4.7 cm. Branch diameters are 38-76 μm and pericentral cell lengths are 58-125 μm. Batrachospermum heterocorticum sp. Nov. is distinguished primarily by a developmental change in cortical filaments from typical cylindrical cells (5.0-7.9 μm diam) in initial stages to enlarged, elliptical cells (12.9-24.1 μm diam) in mature axes. Another unique feature of this species is carpogonia with cylindrical, pedicellate trichogynes on straight carpogonial branches in mid to outer portions of lateral whorls. Other characteristics of B. heterocorticum include the following: olive-green color, 2-6 cm length, dichotomous to trichotomous fascicles in 4-7 tiers, 385-647 μm whorl diameters, 109-198 μm carpospore diameters and relatively small "chantransia" filaments. [ABSTRACT FROM AUTHOR]

The carpogonial branches of Batrachospermum involutum to section Batrachospermum, are similar in ultrastructure to nearby fascicles, having uninucleate cells with abundant starch granules and several peripheral, well-developed chloroplasts (up to 10 μlong). In contrast, the short carpogonial branch cells of Batrachospermum helminthosum (section Vires- cent/a) have no visible starch and chloroplasts are reduced in size (up to 2 p.m long) with few thylakoids. The breakdown of cross walls among cells of the carpogonial branch's also common in B. helminthosum but does not occur in B. involutum. As a result of cross wall breakdown in the former species, 2-7 nuclei can occur in a continuous cytoplasm. Trichogynes in both species contain scattered mitochondria. vesicles/small vacuoles, osmiophilic globules, endoplasmic reticulum (ER) and small chloroplasts. a structures also occur in the trichogyne in B. invofutum. The carpogonial base was fully observed only in B. involutum and it contains a prominent nucleus, ER, chloroplasts and a pit plug connecting it to the subtending carpogonial branch cell. Partial observations of carpogonial branches and carpogonia were made on four other members of the family Batrachospermaceae. [ABSTRACT FROM AUTHOR]

Vegetative and reproductive morphology and ultra-structure were examined for the three genera of the freshwater red algal family Lemaneaceae: Lemanea (two species, seven populations), Paralemanea (two species, three populations) and Psilosiphon (one species, one population). Psilosiphon is readily distinguished from the other two genera in having an outer cortex composed of well-defined filaments interconnected with a dense medulla (both cell types being little vacuolated), spores cleaving off obliquely, putative spermatangia scattered on the thallus sur- face and reproduction by adventitious filaments. Based on the distinctness of this genus (and corroborated by molecular phylogenies in preparation), a new family is described, the Psilosiphonaceae. Lemanea and Paralemanea appear to be closely related, with an outer cortex that has cells of increasing size and vacuolation from the periphery to the interior and not in obvious rows, a central lumen that contains few ray cells but no medullary filaments, sexual reproduction with spermatangia in distinct clusters, and carpospores in chains, some of which can germinate in the thallus lumen. Lernanea and Paralemanea have distinguishing characteristics that the other genus does not: for Lemanea, hair cells, ray cells abutting the outer cortex and spermatangia in patches; for Paralemanea, no hair cells or ray cells oppressed to the outer cortex, inner cortical filaments surrounding the central axis and spermatangia in rings. [ABSTRACT FROM AUTHOR]

Freshwater red algae can be categorized into several morphological groups that contend with flow in different ways. Crust and tufts occur within the boundary layer and thereby may avoid mechanical stress caused by flow. The more tolerant semi-erect forms can be divided into mucilaginous and non-mucilaginous filaments as well as tissue-like thalli. Twelve taxa from these groups occur at a wide range of current velocities (&Xsline; = 24-58 cm · s[SUP-1]). There is a significant increase in strength of these forms in a gradient from tufts (&Xsline; = 12 ± 7 kN · m[SUP-2]) to mucilaginous filaments (&Xsline; = 530 ± 160 kN · m[SUP-2]) to nonmucilaginous filaments and tissues (&Xsline; = 1400 ± 400 kN · m[SUP-2]). In terms of breaking extension, no consitent trend is observed among the different morphologies; the range is 11.3-29.2% beyond the original length. Sirodotia suecica Kylin produces the least increase in dragforce with increasing flow and thus the lowest E value (-1.27) whereas the large mucilaginous species Batrachopermum boryanum Sirod. And B. virgatum (Kütz.) Sirod. Show the highest drag forces and E values (-0.45 to -0.33). Almost a ten-fold range in estimated current velocities is required to break apart the freshwater red algae tested. Predicted velocities at which the morphological groups break are as follows: tufts 80 ± 30 cm · s[SUP-1]; mucilaginous filaments, 160 ± 90 cm· s[SUP-1] and tissue, 580 ± 150 cm · s[SUP-1]. Implications regarding evolution of freshwater Rhodophyla are discussed. [ABSTRACT FROM AUTHOR]

Studies the morphometry of freshwater red algae Batrachospermum (B) populations in New England. Size ranges of the algae; Morphological variability of the species; Distinction of the population from B. boryanum and B. ectocarpum.

In a survey of the distribution of Bangia atropurpurea (Roth) Ag. Along the north and east shorelines of the Laurentian Great Lakes, it was observed that this species was concentrated in the lower lakes. Asexual reproduction by monospore formation was the only form of reproduction in these populations. First generation germlings derived from these spores grew in a wide range of salinities from 1 to 26%, but the rate was inversely proportional to salinity. In addition, acclimation of parent plants to fresh-water or marine media prior to sporulation affected growth rates of first generation germlings placed into a series of salinities. By the second and third generation, germlings with a lineage of seawater showed a preference for the higher salinities, 19 and 26%. Plants collected in Lake Ontario exhibited no decline in photosynthetic rate as salinity was raised by 13% for 15 min. At 26% the rate was reduced by half and thylakoids were disrupted in the region of the pyreniod. On the other hand, third generation plants with a history of seawater attained maximum photosynthetic rates at 26% and contained a normal thylakoid organization. Three chromosomes were observed in these plants, which agrees with some of the previous findings for marine Bangia. Origins and taxonomic status of Bangia growing in the Great Lakes are discussed in light of these findings. [ABSTRACT FROM AUTHOR]

Reports on the use of the sequence data from the large subunit of ribulose-1,5-biphosphate carboxylase/oxygenase gene and 18S ribosomal DNA of taxa in the freshwater order Batrachospermales to construct phylogenetic hypotheses. Generation of trees from each gene as well as a combined data set which were largely congruent; Consistent occurrence of Rhododraparnaldia on an early branch within the Acrochaetiales-Palmariales.

Presents comparative studies on the cell walls of sexual and asexual Bangia atropurpurea. Histochemical study of the nature and distribution of acidic and neutral cell wall polysaccharides; Detection of neutral polysaccharides in the outer coating; Presence of acidic polysaccharides in the outer wall material; Change in the nature of the acidic component during sexual reproduction.

Chromosome number and morphology as well as reproductive seasonality were examined in Bangia populations collected from 88 sites along the British Columbia coasts. Sexual filaments were recorded at 35 sites and asexual filaments at 58. Four different types of Bangia were determined. These were characterized by reproductive state and chromosome number, as well as by their seasonality and range of distribution. A summer-fall three-chromosome sexual type occurred from approximately 50° N northward and a winter-spring four-chromosome sexual type had a northerly limit of approximately 54°N. extending to the southernmost areas of British Columbia. Two asexual types occurred, exhibiting little seasonality, six-chromosome populations at three southerly sites only. Karyograms were prepared for the four chromosomal types, assigning tentative centromere locations. Somatic chromosome pairing was reported for the first time in the Rhodophyta. [ABSTRACT FROM AUTHOR]

Representatives of the freshwater red algal family Thoreaceae were studied to resolve their taxonomic and phylogenetic status. Three specimens of Nemalionopsis and five collections of Thorea were examined for pit plug ultrastructure and analyzed for the sequences of the genes coding for the large subunit of RUBISCO (rbc L) and the small subunit of rRNA (18S rRNA). The phylogenetic trees generated from the two genes, and a combined tree all showed the Thoreaceae to be contained in a well-supported monophyletic clade that is separate from the other two families currently classified in the Batrachospermales, the Batrachospermaceae and the Lemaneaceae. In addition, secondary structure elements of the 18S rRNA gene were observed at positions 650 and 1145 (Escherichia coli numbering system) that are not present in other members of the Rhodophyta. The pit plugs of the gametophytic and chantransia stages of the Thoreaceae contain two cap layers, the outer one of which is typically plate-like, though occasionally inflated ones have been seen. No pit plug cap membrane has been observed. These findings indicate the Thoreaceae has been misclassified in the Batrachospermales and should be placed in its own order, the Thoreales. This order is characterized by having freshwater representatives with multiaxial gametophytes, a uniaxial chantransia stage, and pit plugs with two cap layers, the outer one of which is usually plate-like. [ABSTRACT FROM AUTHOR]