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Morgan L. Vis - One of the best experts on this subject based on the ideXlab platform.
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paludicola gen nov and revision of the species formerly in Batrachospermum section turfosa batrachospermales rhodophyta
Journal of Phycology, 2020Co-Authors: Morgan L. Vis, Daryl W Lam, Janina Lee, Pertti Eloranta, Iara S Chapuis, Orlando NecchiAbstract:Since the first phylogenetic study of the order Batrachospermales, Batrachospermum was shown to be paraphyletic. Subsequently, sections of the genus have been methodically investigated using DNA sequences and morphology in order to propose new genera and delineate species. Batrachospermum section Turfosa is the last section with multiple species yet to be examined. New sequence data of specimens from Europe and the United States were combined with the sparse sequence data already available. Phylogenetic analyses using rbcL and COI-5P sequences showed this section to be a well-supported clade, distinct from Batrachospermum section Batrachospermum and its segregate genera. Section Turfosa is raised to the generic rank as Paludicola gen. nov. Substantial genetic variation within the genus was discovered and 12 species are recognized based on DNA sequence data as well as morphological characters and geographic distribution. The following morphological characters were applied to distinguish species: branching pattern (pseudodichotomous or irregular), whorl size (reduced or well developed), primary fascicles (curved or straight), spermatangia origin (primary or secondary fascicles), and carposporophyte arrangement (loose or dense). Previously published species were transferred to the new genus: P. turfosa, P. keratophyta, P. orthosticha, P. phangiae, and P. periploca. Seven new species are proposed as follows: P. groenbladii from Europe; P. communis, P. johnhallii, and P. leafensis from North America; and P. aquanigra, P. diamantinensis, and P. turfosiformis from Brazil. In addition, three unsequenced species in the section, P. bakarensis, P. gombakensis, and P. tapirensis, were transferred to the new genus.
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revision of Batrachospermum section macrospora batrachospermales rhodophyta with the establishment of the new genus montagnia
Phycologia, 2019Co-Authors: Orlando Necchi, Monica O Paiano, Morgan L. VisAbstract:To resolve the paraphyly of Batrachospermum, the sections of the genus have been methodically investigated using DNA sequence data and morphology; this has resulted in the raising of many sections ...
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revision of Batrachospermum section virescentia batrachospermales rhodophyta with the establishment of the new genus virescentia stat nov
Cryptogamie Algologie, 2018Co-Authors: Orlando Necchi, Douglas De Castro Agostinho, Morgan L. VisAbstract:In recent years, sections of the paraphyletic genus Batrachospermum have been investigated using DNA sequence data, as well as morphology and some have been raised to genera in order to resolve this paraphylly. The species of Batrachospermum section Virescentia form a well-supported clade and we propose the raising of this section to the genus Virescentia stat. nov. In addition, we re-evaluated the characters used to circumscribe species by reexamination of type specimens and new collections in historically important areas. Of the eleven previously accepted species, we recognize five species and a new species is proposed as follows: V. crispata, V. gulbenkiana (synomyms V. azeredoi and V. ferreri), V. helminthosa (type species), V. viride-americana sp. nov., V. viride-brasiliensis and V. vogesiaca. The species are circumscribed on the basis of morphological characteristics (shape of fascicles, occurrence of secondary fascicles, disposition of carpogonial branches and size of carpogonia), geographic distribution, and DNA sequence data (rbcL and COI-5P). Descriptions, identification key and photomicrographs are presented for each recognized species. Two potential species from Japan based on DNA sequence data remained undescribed due to lack of voucher specimens for morphological observation. Other species previously assigned to the section Virescentia are referred to other genera of Batrachospermales based on morphology (disposition of carpogonial branches, shape of trichogynes, types of gonimoblast filaments and arrangement of carposporophytes).
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a new genus volatus and four new species of Batrachospermum sensu stricto batrachospermales rhodophyta
Phycologia, 2017Co-Authors: Iara S Chapuis, Orlando Necchi, Shulian Xie, Marina Aboal, Giuseppe C Zuccarello, Pedro Miguel Sanchez Castillo, Morgan L. VisAbstract:Abstract: Collections of Batrachospermales from 13 stream sites in North America (Canada and United States), Europe (Spain) and Asia (China) were examined. Phylogenetic analyses of sequences data from the plastid-encoded ribulose 1,5-bisphosphate carboxylase/oxygenase large subunit gene (rbcL) and the mitochondrial-encoded cytochrome oxidase 1 gene barcode region (COI-5P), along with morphological studies, suggested that these collections represent new taxa. Three species in a proposed new genus Volatus are described: V. carrionii sp. nov., V. personatus sp. nov. and V. ulterior sp. nov. Four new species of Batrachospermum sensu stricto are also described: B. dapsile sp. nov., B. naiadis sp. nov., B. pozoazulense sp. nov. and B. shanxiense sp. nov. Taxa proposed based on the molecular analyses were in many cases difficult to distinguish with unique morphological characters. The new genus Volatus shares the distinctive characteristic of twisted or curled carpogonium-bearing branches with Kumanoa and Tuomey...
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nocturama gen nov nothocladus s lat and other taxonomic novelties resulting from the further resolution of paraphyly in australasian members of Batrachospermum batrachospermales rhodophyta
Journal of Phycology, 2016Co-Authors: Timothy J. Entwisle, Sarah Stewart, Emily T Johnston, Daryl W Lam, Morgan L. VisAbstract:The informal "Australasica Group" was established in 2009 to include several Australasian endemic Batrachospermum species, a few species of the cosmopolitan Batrachospermum section Setacea, and the South American endemic Petrohua bernabei. Although useful for communication purposes, no formal taxonomic designation was proposed due to weakly supported basal nodes. The present research took a two-pronged approach of adding more taxa (29 additional specimens) as well as more sequence data (LSU, cox1, psaA, and psbA markers added to rbcL data) to provide better resolution. The resulting tree showed improved statistical support values (Bayesian posterior probability and maximum likelihood bootstrap) for most nodes providing a framework for taxonomic revision. Based on our well-resolved phylogeny, a new genus, Nocturama, is proposed for a clade of Batrachospermum antipodites specimens. The circumscription of Nothocladus is expanded to include Batrachospermum section Setacea and four additional sections composed of at least 10 species, mostly from Australia and New Zealand. One new species added to the data set, N. diatyches, did not form a clade with the other species of section Setaceus, where it was classified previously, rendering that section paraphyletic. To resolve this, N. diatyches and the morphologically similar species N. latericius are included with N. theaquus, in the new section Theaquus within Nothocladus s. lat. A specimen from Australia unaligned to these clades was sister to the Australia-New Zealand genus Psilosiphon and the cosmopolitan B. cayennense, but lacked statistical support. This specimen has the gross morphology of Batrachospermum s. lat. and is here provisionally assigned to that genus, as B. serendipidum sp. nov.
Robert G Sheath - One of the best experts on this subject based on the ideXlab platform.
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phylogenetic relationship of Batrachospermum species batrachospermales rhodophyta from coastal streams in french guiana
Phycologia, 2005Co-Authors: Morgan L. Vis, Wayne B Chiasson, Robert G SheathAbstract:Abstract Eighteen samples of eight Batrachospermum species from collections in French Guiana, South America, were analysed utilizing RUBISCO large subunit (rbcL) gene sequence data in order to assess phylogenetic placement and evaluate intra-specific sequence variation among continents. Five species, B. ambiguum (two samples), B. gracillimum, B. guyanense, B. intortum and B. nodiflorum (two samples), belong to section Contorta. Section Aristata was represented by B. macrosporum (six samples) and B. cayennense (three samples) and Section Turfosa by B. turfosum (two samples). Maximum parsimony, distance, maximum likelihood and Bayesian analyses produced phylogenetic trees with similar topologies. The species from section Contorta were in a well-supported clade with previously sequenced taxa of that section. However, the subsectional classification sometimes applied to this section was not supported by the molecular data. Samples of B. macrosporum and B. cayennense were sister to each other, but they were on...
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phenology and phylogenetic positioning of the hawaiian endemic freshwater alga Batrachospermum spermatiophorum rhodophyta batrachospermales
Phycological Research, 2004Co-Authors: Alison R Sherwood, Morgan L. Vis, Robert G SheathAbstract:SUMMARY The only known population of Batrachospermum spermatiophorum Vis et Sheath, located in a small stream on east Maui, Hawaii, was sampled from November 2001 to October 2002 to investigate its phenology. Additionally, the taxonomic status of the alga was examined. Phylogenetic analyses of the large subunit of the ribulose-1,5-bisphosphate carboxylase/oxygenase (rbcL) gene for B. spermatiophorum confirm its placement within the Section Contorta of the genus Batrachospermum. Comparisons with rbcL gene sequences for all other available Batrachospermum species, including 10 other members of the Section Contorta, illustrate that B. spermatiophorum is distinct in its rbcL nucleotide sequence and should be maintained as a separate species. The phenology of B. spermatiophorum differed from most studies of Batrachospermum reproduction in that the gametophytes were present year round, and no macroscopic chantran-sia stages were identified at any point during the present study. Maximum plant length was highest in the late fall and early winter months, while gametangial production peaked in February and March. Carposporophyte abundance rose sharply in July and August, and the percentage of carposporophytes producing carpospores was highest in late summer and early fall months. Although significant correlations were determined among stream conditions and among phenological characteristics, only pH was associated with several of the reproductive characters, which is unusual for studies of Batrachospermum phenology. Timing of sexual reproduction for all macroalgal community members in the stream site was not coordinated, with some reproducing year round and others more sporadically. The year-round presence of Batrachospermum gametophytes may be a result of a combination of smaller seasonal changes in cues such as day length and water temperature in the tropical environment than occur in temperate locations, and lack of extreme conditions that might inhibit the persistence of the gametophyte.
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150 phylogenetic systematics and phenology of the hawaiian endemic freshwater red alga Batrachospermum spermatiophorum
Journal of Phycology, 2003Co-Authors: Alison R Sherwood, Morgan L. Vis, Robert G SheathAbstract:The only known population of Batrachospermum spermatiophorum Vis et Sheath, located in a small stream on east Maui, Hawaii, was sampled from November 2001 to October 2002 to investigate its phenology and taxonomy. Phylogenetic analyses of the rbcL gene for B. spermatiophorum confirm its placement within the Section Contorta. Comparison with rbcL gene sequences for all other available Batrachospermum species illustrates that B. spermatiophorum is distinct in its rbcL nucleotide sequence and should be maintained as a separate species. The phenology of B. spermatiophorum differed from similar studies on temperate Batrachospermum species in that gametophytes were present year round, and no “chantransia” stages were identified at any point during the study. Maximum plant length was highest in late fall and early winter months, while gametangial production peaked in February and March. Carposporophyte abundance rose sharply in July and August, and the percent of carposporophytes producing carpospores was highest in late summer and early fall months. The year-round presence of gametophytes may be a result of fewer seasonal cues in the tropical environment than occur in temperate locations.
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a molecular and morphological investigation of the relationship between Batrachospermum spermatoinvolucrum and b gelatinosum batrachospermales rhodophyta
European Journal of Phycology, 1998Co-Authors: Morgan L. Vis, Robert G SheathAbstract:Four populations of the newly described freshwater red algal species Batrachospermum spermatoinvolucrum were sampled from British Columbia on the west coast of North America and Labrador on the east. The rDNA internal transcribed spacer (ITS) 1 and 2 sequences, RUBISCO large subunit (rbcL) gene data for three of the populations and morphometric characteristics were compared with those of B. gelatinosum. In addition, the key feature distinguishing B. spermatoinvolucrum, spermatangia on the involucral filaments of the carpogonial branch, was investigated seasonally in one British Columbia population of this species. The ITS analysis suggested that the B. spermatoinvolucrum populations were more closely related to particular B. gelatinosum populations than to each other and did not form a monophyletic clade. Two populations of B. spermatoinvolucrum from Labrador and British Columbia had identical rbcL sequences that were distinct from that of B. gelatinosum. However, the rbcL sequence from the third populati...
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ultrastructure of carpogonia and carpogonial branches of Batrachospermum helminthosum and Batrachospermum involution batrachospermales rhodophyta
Phycological Research, 1997Co-Authors: Robert G Sheath, Kirsten M MullerAbstract:SUMMARY The carpogonial branches of Batrachospermum involutum of section Batrachospermum are similar in ultrastructure to nearby fascicles, having uninucleate cells with abundant starch granules and several peripheral, well-developed chloropiasts (up to 10 μm long). In contrast, the short carpogonial branch cells of Batrachospermum helminthosum (section Virescentia) have no visible starch and chloropiasts are reduced in size (up to 2 μm long) with few thylakoids. The breakdown of cross walls among cells of the carpogonial branch is 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 chloropiasts. Polylamellate structures also occur in the trichogyne in B. involution. The carpogonial base was fully observed only in B. involutum and it contains a prominent nucleus, ER, chloropiasts 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.
Orlando Necchi - One of the best experts on this subject based on the ideXlab platform.
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paludicola gen nov and revision of the species formerly in Batrachospermum section turfosa batrachospermales rhodophyta
Journal of Phycology, 2020Co-Authors: Morgan L. Vis, Daryl W Lam, Janina Lee, Pertti Eloranta, Iara S Chapuis, Orlando NecchiAbstract:Since the first phylogenetic study of the order Batrachospermales, Batrachospermum was shown to be paraphyletic. Subsequently, sections of the genus have been methodically investigated using DNA sequences and morphology in order to propose new genera and delineate species. Batrachospermum section Turfosa is the last section with multiple species yet to be examined. New sequence data of specimens from Europe and the United States were combined with the sparse sequence data already available. Phylogenetic analyses using rbcL and COI-5P sequences showed this section to be a well-supported clade, distinct from Batrachospermum section Batrachospermum and its segregate genera. Section Turfosa is raised to the generic rank as Paludicola gen. nov. Substantial genetic variation within the genus was discovered and 12 species are recognized based on DNA sequence data as well as morphological characters and geographic distribution. The following morphological characters were applied to distinguish species: branching pattern (pseudodichotomous or irregular), whorl size (reduced or well developed), primary fascicles (curved or straight), spermatangia origin (primary or secondary fascicles), and carposporophyte arrangement (loose or dense). Previously published species were transferred to the new genus: P. turfosa, P. keratophyta, P. orthosticha, P. phangiae, and P. periploca. Seven new species are proposed as follows: P. groenbladii from Europe; P. communis, P. johnhallii, and P. leafensis from North America; and P. aquanigra, P. diamantinensis, and P. turfosiformis from Brazil. In addition, three unsequenced species in the section, P. bakarensis, P. gombakensis, and P. tapirensis, were transferred to the new genus.
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revision of Batrachospermum section macrospora batrachospermales rhodophyta with the establishment of the new genus montagnia
Phycologia, 2019Co-Authors: Orlando Necchi, Monica O Paiano, Morgan L. VisAbstract:To resolve the paraphyly of Batrachospermum, the sections of the genus have been methodically investigated using DNA sequence data and morphology; this has resulted in the raising of many sections ...
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revision of Batrachospermum section virescentia batrachospermales rhodophyta with the establishment of the new genus virescentia stat nov
Cryptogamie Algologie, 2018Co-Authors: Orlando Necchi, Douglas De Castro Agostinho, Morgan L. VisAbstract:In recent years, sections of the paraphyletic genus Batrachospermum have been investigated using DNA sequence data, as well as morphology and some have been raised to genera in order to resolve this paraphylly. The species of Batrachospermum section Virescentia form a well-supported clade and we propose the raising of this section to the genus Virescentia stat. nov. In addition, we re-evaluated the characters used to circumscribe species by reexamination of type specimens and new collections in historically important areas. Of the eleven previously accepted species, we recognize five species and a new species is proposed as follows: V. crispata, V. gulbenkiana (synomyms V. azeredoi and V. ferreri), V. helminthosa (type species), V. viride-americana sp. nov., V. viride-brasiliensis and V. vogesiaca. The species are circumscribed on the basis of morphological characteristics (shape of fascicles, occurrence of secondary fascicles, disposition of carpogonial branches and size of carpogonia), geographic distribution, and DNA sequence data (rbcL and COI-5P). Descriptions, identification key and photomicrographs are presented for each recognized species. Two potential species from Japan based on DNA sequence data remained undescribed due to lack of voucher specimens for morphological observation. Other species previously assigned to the section Virescentia are referred to other genera of Batrachospermales based on morphology (disposition of carpogonial branches, shape of trichogynes, types of gonimoblast filaments and arrangement of carposporophytes).
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a new genus volatus and four new species of Batrachospermum sensu stricto batrachospermales rhodophyta
Phycologia, 2017Co-Authors: Iara S Chapuis, Orlando Necchi, Shulian Xie, Marina Aboal, Giuseppe C Zuccarello, Pedro Miguel Sanchez Castillo, Morgan L. VisAbstract:Abstract: Collections of Batrachospermales from 13 stream sites in North America (Canada and United States), Europe (Spain) and Asia (China) were examined. Phylogenetic analyses of sequences data from the plastid-encoded ribulose 1,5-bisphosphate carboxylase/oxygenase large subunit gene (rbcL) and the mitochondrial-encoded cytochrome oxidase 1 gene barcode region (COI-5P), along with morphological studies, suggested that these collections represent new taxa. Three species in a proposed new genus Volatus are described: V. carrionii sp. nov., V. personatus sp. nov. and V. ulterior sp. nov. Four new species of Batrachospermum sensu stricto are also described: B. dapsile sp. nov., B. naiadis sp. nov., B. pozoazulense sp. nov. and B. shanxiense sp. nov. Taxa proposed based on the molecular analyses were in many cases difficult to distinguish with unique morphological characters. The new genus Volatus shares the distinctive characteristic of twisted or curled carpogonium-bearing branches with Kumanoa and Tuomey...
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phylogeography of the freshwater red alga Batrachospermum viride brasiliense rhodophyta batrachospermales
Phycological Research, 2017Co-Authors: Monica O Paiano, Orlando NecchiAbstract:Phylogeography of B atrachospermum viride‐brasiliense was investigated using two mitochondrial regions: the cox2‐3 spacer and the barcode region of cox1 gene. Eighty‐seven individuals were analyzed from nine stream segments throughout its distribution in Brazil. Ten cox2‐3 spacer and nine cox1 haplotypes were observed among the individuals studied (87 vs. 43, respectively). Divergences among haplotypes were relatively low (≤2.4% for cox2‐3 and ≤1.8% for cox1). Most locations have a single haplotype, whereas only two locations had two haplotypes for both markers. The haplotype network for cox2‐3 showed a phylogeographic trend from the south towards the southeast with haplotypes from the southeast more closely related. For cox1 a trend from the southeast spreading towards the south and north was revealed, with the southern haplotypes more closely associated. Results clearly indicated that B . viride‐brasiliense represents a single species and the phylogeographic pattern consisted of a closely connected group of haplotypes from southern and southeastern Brazil. Levels of intra‐ and inter‐population variation were similar for the two markers with slightly higher values for cox2‐3. The trend observed in this study is similar to that in other members of Batrachospermales with little variation within a stream segment (one or two haplotypes) and more distant haplotypes showing higher divergences. This pattern could be attributed to the fact that colonization of a site might be rare by a single event with subsequent proliferation of the population. The geographic distribution of B . viride‐brasiliense was interpreted according to the biogeographic models proposed for South America being limited to three morpho‐climatic domains or biogeographic provinces: tropical Atlantic rainforest, sub‐tropical rainforest and cerrado (Brazilian savannah).
Kathleen M Cole - One of the best experts on this subject based on the ideXlab platform.
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distribution and systematics of Batrachospermum batrachospermales rhodophyta in north america 8b section Batrachospermum previously described species excluding Batrachospermum gelatinosum
European Journal of Phycology, 1996Co-Authors: Morgan L. Vis, Robert G Sheath, Kathleen M ColeAbstract:Sixty-two North American populations of seven previously described species belonging to Batrachospermum sect. Batrachospermum were examined and compared with appropriate type specimens using morphometrics and image analysis. All populations were similar to the respective type specimens in qualitative and quantitative characteristics, but the range of some morphological features has been extended. B. boryanum was the most abundant and widespread species, being collected in 34 stream sites from Newfoundland and British Columbia in the north to Georgia in the south. The other six species — B. anatinum, B. arcuatum, B. confusum, B. heterocorticum, B. pulchrum and B. skujae — were more localized and occurred in six or fewer streams. B. anatinum was restricted to Missouri, Arkansas and Virginia and B. arcuatum was collected in western North America from Alaska to Mexico. The distribution of B. confusum was disjunct, with populations occurring in Alberta, Quebec, Newfoundland, Maine and Missouri. B. heterocortic...
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distribution and systematics of Batrachospermum batrachospermales rhodophyta in north america 8a section Batrachospermum Batrachospermum gelatinosum
European Journal of Phycology, 1996Co-Authors: Morgan L. Vis, Robert G Sheath, Kathleen M ColeAbstract:Eighty-six populations of Batrachospermum gelatinosum were examined from throughout its known range in North America and were compared using multivariate morphometrics and image analysis. Morphological variability was as great in individual populations as that measured among locations. Populations pooled for each biome showed a north-south trend in whorl and carpogonium size. The mean measurements for the tundra were significantly smaller in whorl diameter and larger in carpogonium size than those for the coastal plain. B. gelatinosum is widely distributed in North America, having been collected from the north slope of Alaska and Baffin Island in the north to Texas and Louisiana in the south. In addition to the populations analysed, herbarium specimens from North America were examined and confirmed locations in 17 US states, four Canadian provinces and the Yukon territory were added. Three populations, two from the boreal forest (Newfoundland) and one from the deciduous forest (Rhode Island), were examine...
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distribution and systematics of Batrachospermum batrachospermales rhodophyta in north america 4 section virescentia
Journal of Phycology, 1994Co-Authors: Robert G Sheath, Morgan L. Vis, Kathleen M ColeAbstract:Thirty-nine populations of Batrachospermum section Virescentia from North America were compared to eight type specimens and two historically important specimens using multivariate morphometrics and image analysis. From this analysis, two species are recognized: B. helminthosum Bory de Saint-Vincent (syn. B. bruziense Sirodot, B. graibussoniense Sirodot, B. sirodotii Skuja ex Flint, B. testale Sirodot, B. virgatum Sirodot nom. illeg., and B. viride Sirodot) and B. elegans Sirodot (syn. B. coerulescens Sirodot nom. illeg.). In B. helminthosum trichogynes are cylindrical to slightly club-shaped with few to no protuberances, whereas in B. elegans half to all of the trichogynes have one to three basal knobs or branches. None of the qualitative features previously used to separate species in this section were found to be of taxonomic value due to their universal presence; quantitative characteristics were highly variable and overlapped among specimens examined. Emended descriptions of both species are provided. Batrachospermum elegans was collected in northeastern U.S.A. and central Costa Rica, whereas B. helminthosum ranged from Nova Scotia to Louisiana and was collected in central Mexico, Costa Rica, and northwestern U.S.A. Batrachospermum julianum Arcangeli and B. transtaganum Reis, previously classified in section Virescentia, were observed to have twisted carpogonial branches and, therefore, should be placed in section Contorta. Sections Setacea and Virescentia of Batrachospermum differ in whorl size, ratio of carposporophyte height to whorl diameter, and trichogyne stalking; hence, we continue to recognize them as being distinct taxonomic entities as originally described.
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distribution and systematics of Batrachospermum batrachospermales rhodophyta in north america 1 section contorta1
Journal of Phycology, 1992Co-Authors: Robert G Sheath, Morgan L. Vis, Kathleen M ColeAbstract:Multivariate morphometrics and image analysis were used to determine the number of well-distinguished infra-generic 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 Flint 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−1), whereas B. intortum and B. globosporum are found in high ion waters (260–1760 μS·cm−1). Detailed descriptions and a key to the five taxa are given.
Emily J Keil - One of the best experts on this subject based on the ideXlab platform.
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distribution morphology and ecological niche of Batrachospermum and sheathia species batrachospermales rhodophyta in the fontanili of the po plain northern italy
European Journal of Phycology, 2015Co-Authors: Nadia Abdelahad, Morgan L. Vis, Giovanna Jona Lasinio, Rossano Bolpagni, Carolina Amadio, Alex Laini, Emily J KeilAbstract:AbstractTwenty-three freshwater springs of the Po plain (northern Italy) were surveyed and visited multiple times during 2011–2013 to assess water quality and algal taxa present. Despite poor water conditions of this human-altered floodplain, a relatively high number of taxa referable to the freshwater red algae, Batrachospermum and Sheathia, were observed. The identity of specimens collected was based on morphology and confirmed with sequence data. The specimens belonged to Sheathia arcuata, S. boryana, Batrachospermum atrum, B. gelatinosum and B. gelatinosum f. spermatoinvolucrum. This is the first report of B. gelatinosum f. spermatoinvolucrum outside North America. Niche analysis revealed a marked difference in the physical and chemical preferences of the freshwater red algae recorded. The occurrence of S. boryana was limited to relatively low nitrate and higher oxygen concentrations. Conversely, the spatial distribution of the other four taxa indicated that they were able to tolerate high concentrati...
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phylogeography of Batrachospermum gelatinosum batrachospermales rhodophyta shows postglacial expansion in europe
Phycologia, 2015Co-Authors: Emily J Keil, Pertti Eloranta, Janina Kwandrans, Taylor R Macy, Pedro Tomas, Marina Aboal, Morgan L. VisAbstract:The freshwater red alga Batrachospermum gelatinosum inhabits streams of Europe and North America and has been collected frequently on both continents. A study of this species in North America showed evidence of a glacial refugium in the southeastern United States with little genetic variation throughout its more northern range in eastern North America. The present study was initiated to investigate its phylogeography throughout Europe and to compare these results with those obtained for North America. Specimens were collected from Belgium, Estonia, Finland, France, Great Britain, Italy, Latvia, Lithuania, Poland and Spain. Both the mitochondrial cytochrome c oxidase subunit I (COI) barcode region and the nuclear rDNA internal transcribed spacer (ITS 1 and 2) regions were analysed. Of the 70 individuals analysed, 12 COI haplotypes were uncovered. In addition, ITS variation of 67 individuals was surveyed and showed 21 haplotypes. The haplotype network of COI data showed a large number of the individuals distributed among three common haplotypes. The other nine haplotypes differed from the common ones by only one to two base pairs and were represented by only one to six individuals. The ITS network had a star appearance with a common haplotype (17 individuals) and many closely related haplotypes with few individuals per haplotype. Compared to North America, there were more COI haplotypes present in Europe (12 vs 5), and the relationship among haplotypes was more complex. The geographic distribution of haplotypes did not appear to follow a glaciation pattern; rather, the common haplotypes were widespread, suggesting a recent expansion.
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Distribution, morphology and ecological niche of Batrachospermum and Sheathia species (Batrachospermales, Rhodophyta) in the fontanili of the Po plain (northern Italy)
2015Co-Authors: Nadia Abdelahad, Morgan L. Vis, Giovanna Jona Lasinio, Rossano Bolpagni, Carolina Amadio, Alex Laini, Emily J KeilAbstract:Twenty-three freshwater springs of the Po plain (northern Italy) were surveyed and visited multiple times during 2011–2013 to assess water quality and algal taxa present. Despite poor water conditions of this human-altered floodplain, a relatively high number of taxa referable to the freshwater red algae, Batrachospermum and Sheathia, were observed. The identity of specimens collected was based on morphology and confirmed with sequence data. The specimens belonged to Sheathia arcuata, S. boryana, Batrachospermum atrum, B. gelatinosum and B. gelatinosum f. spermatoinvolucrum. This is the first report of B. gelatinosum f. spermatoinvolucrum outside North America. Niche analysis revealed a marked difference in the physical and chemical preferences of the freshwater red algae recorded. The occurrence of S. boryana was limited to relatively low nitrate and higher oxygen concentrations. Conversely, the spatial distribution of the other four taxa indicated that they were able to tolerate high concentrations of nitrate (up to 53.6 mg l–1) and low rates of dissolved oxygen saturation (as low as 3%). All the specimens of B. gelatinosum collected had few to many trichogynes deformed by a basal protuberance or knob, a structure previously unobserved in this species. No other taxa showed any deformities. The ecological analyses confirmed the existence of a relationship between the environmental conditions of the springs and the occurrence of knobs.
