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D. Wilson Freshwater - One of the best experts on this subject based on the ideXlab platform.
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Polysiphonia sensu lato (Ceramiales, Florideophyceae) species of Caribbean Panama including Polysiphonia lobophoralis sp. nov. and Polysiphonia nuda sp. nov .
Botanica Marina, 2012Co-Authors: Nadya R. Mamoozadeh, D. Wilson FreshwaterAbstract:Only two species of Polysiphonia sensu lato (predominately species of Polysiphonia and Neosiphonia ) have been reported from Caribbean Panama. In contrast, 16 species are documented from the neighboring countries of Costa Rica and Colombia. Molecular-assisted identifi cation using plastidencoded ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit gene ( rbc L) and mitochondria-encoded cytochrome c oxidase subunit I gene (COI) loci identifi ed 14 species from 38 samples collected along the Caribbean coast of Panama. Morphological character states were examined and used to identify each sample, and phylogenetic relationships among these species were estimated through maximum likelihood analyses of rbc L and nuclear-encoded SSU sequence data. Neosiphonia ferulaceae , N. tongatensis , Polysiphonia binneyi , P. havanensis , P. macrocarpa , P. pseudovillum , P. schneideri , P. subtilissima , and two species that could only be identifi ed as P. cf. sertularioides are reported for the fi rst time from Panama. Polysiphonia pentamera , a species only known from the eastern Pacifi c is reported for the fi rst time in the Caribbean, and two new species, P. lobophoralis and P. nuda are described. A key to Caribbean Panama species, descriptions of species morphology and remarks on taxonomy and relationships are provided. These fi ndings demonstrate that previous limited reports of Polysiphonia sensu lato species from Panama resulted from a lack of study, rather than a lack of diversity, within the region.
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Taxonomic notes on Caribbean Neosiphonia and Polysiphonia (Ceramiales, Florideophyceae): five species from Florida, USA and Mexico
Botanica Marina, 2011Co-Authors: Nadya R. Mamoozadeh, D. Wilson FreshwaterAbstract:Molecular-assisted identification using plastid-encoded rbcL and mitochondrion-encoded COI loci identified five species of Polysiphonia sensu lato from 16 Florida and Caribbean Mexico samples. Morphological character states were examined and used to identify these species as Neosiphonia bajacali comb. nov., N. echinata comb. nov., N. sphaerocarpa, N. tepida, and Polysiphonia anomala. Descriptions are provided and the phylogenetic relationships of the five species were determined through maximum likelihood analyses of rbcL and nuclear-encoded SSU sequence data. Neosiphonia bajacali and N. echinata had a combination of character states described for Neosiphonia: rhizoids cut-off from pericentral cells, lateral branch or trichoblast initials on every segment in a spiral pattern, tetrasporangia in spiral series, and spermatangial stichidia developing as bifurcations of trichoblasts, and these new combinations are proposed. Examination of N. echinata, P. fracta and North Carolina specimens identified as P. breviarticulata revealed no significant morphological differences. Polysiphonia fracta is proposed as a synonym of N. echinata and the presence of P. breviarticulata within the western Atlantic is questioned. This is the first report of N. bajacali from the Caribbean and the first report of N. echinata from Caribbean Mexico.
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Consistency of Morphological Characters Used to Delimit Polysiphonia Sensu Lato Species (Ceramiales, Florideophyceae): Analyses of North Carolina, USA Specimens
Phycologia, 2008Co-Authors: Brooke Stuercke, D. Wilson FreshwaterAbstract:B. Stuercke & D.W. Freshwater. 2008. Consistency of morphological characters used to delimit Polysiphonia sensu lato species (Ceramiales, Florideophyceae): analyses of North Carolina, USA specimens...
Myung-sook Kim - One of the best experts on this subject based on the ideXlab platform.
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The phylogenetic position of Polysiphonia scopulorum (Rhodomelaceae, Rhodophyta) based on molecular analyses and morphological observations of specimens from the type locality in Western Australia
Phytotaxa, 2017Co-Authors: John M. Huisman, Byeongseok Kim, Myung-sook KimAbstract:Considerable uncertainty surrounds the phylogenetic position of Polysiphonia scopulorum , a species with an apparently cosmopolitan distribution. Here we report, for the first time, molecular phylogenetic analyses using plastid rbc L gene sequences and morphological observations of P. scopulorum collected from the type locality, Rottnest Island in Western Australia. Morphological characteristics of the Rottnest Island specimens allowed unequivocal identification, however, the sequence analyses uncovered discrepancies in previous molecular studies that included specimens identified as P. scopulorum from other locations. The phylogenetic evidence clearly revealed that P. scopulorum from Rottnest Island formed a sister clade with P. caespitosa from Spain (JX828149 as P. scopulorum ) with moderate support, but that it differed from specimens identified as P. scopulorum from the U.S.A. (AY396039, EU492915). In light of this, we suggest that P. scopulorum be considered an endemic species with a distribution restricted to Australia. Our results showed the existence of several distinct clades among the species of Polysiphonia sensu lato , including the clade containing P. scopulorum which did not join with the generitype Polysiphonia stricta (i.e., Polysiphonia sensu stricto ). This suggests that the P. scopulorum clade might represent a separate genus, however, further studies including multi-gene analyses are recommended before recognizing any segregate taxa.
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on the morphology and molecular evidence
2016Co-Authors: Byeongseok Kim, Myung-sook KimAbstract:There are recognized three new species of Polysiphonia sensu lato at a 10-20 m water depth from Jeju Island, Korea. We described the morphology of three new species and analyzed rbcL sequences to infer phylogenetic relationships among Polysiphonia sensu lato. Polysiphonia amplacapilli sp. nov. is characterized by an epiphytic, discoid holdfast, 5-7 pericentral cells, large trichoblasts, lateral branches connecting with trichoblasts, only slightly corticated in the basal parts, cut-off rhizoids and a spiral arrangement of tetrasporangia. Polysiphonia morroides sp. nov. is characterized by saxicolous, cut-off rhizoids, four pericentral cells, ecorticate, spiral arrangement of tetrasporangia, and it was collected at the fast-flowing water habitat in 20-25 m depth. Polysiphonia sabulosia sp. nov. is characterized by ecorticate, 5-6 pericentral cells, a single filamentous trichoblast, lateral branches connecting with the trichoblasts, cut-off rhizoids, and spiral arrangement of tetrasporangia, and is growing in the sandy locations. The phylogenetic analysis of rbcL sequences demonstrated that three new species are clearly distinguished from other species of Polysiphonia sensu lato. Key Words: molecular phylogeny; morphology; new species; Polysiphonia sensu lato; rbcL; taxonom
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Taxonomic reassessment of Polysiphonia foetidissima (Rhodomelaceae, Rhodophyta) and similar species, including P. schneideri, a newly introduced species in Europe
European Journal of Phycology, 2013Co-Authors: Pilar Díaz-tapia, Myung-sook Kim, Antonio Secilla, Ignacio Bárbara, Javier CremadesAbstract:Morphological and molecular studies were carried out on two Polysiphonia with 6–9 pericentral cells from the Atlantic Iberian Peninsula. A detailed description is provided for P. foetidissima, a poorly known species originally described from the UK that is widespread and abundant in the Iberian Peninsula. Polysiphonia schneideri, originally described from Atlantic U.S.A. and Bermuda, is reported for the first time in Europe (Southern Spain). It was collected attached to man-made structures such as floating docks and artificial substrata for aquaculture and is believed to be a newly introduced species in Europe. In addition, the taxonomy of seven morphologically similar Polysiphonia was reassessed. A comparative study of type materials showed that the Mediterranean P. stuposa is morphologically different from its alleged synonym P. foetidissima. Instead, molecular and morphological evidence showed that P. foetidissima is a synonym of the widely reported (Atlantic and Pacific) P. tepida. Polysiphonia foetid...
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Taxonomic Note of Polysiphonia pacifica (Ceramiales, Rhodophyta) Complex with Focus on Pacific Isolates
ALGAE, 2005Co-Authors: Myung-sook Kim, Eun Chan YangAbstract:Polysiphonia pacifica is rhodomelaceous red algal species that includes five varieties in Pacific Ocean: P. pacifica var. delicatula, P. pacifica var. distans, P. pacifica var. determinata, P. pacifica var. disticha, and P. pacifica var. gracilis. We here report morphology and phylogeny of P. pacifica to confirm the relationships among previously described varieties as a loan of type specimens from US and to assess phylogenetic relationships of closely related species using plastid protein-coding rbcL gene. Polysiphonia pacifica is distinguished by having creeping filaments attached by unicellular rhizoids not cut off by cross walls, four pericentral cells, ecorticate, trichoblasts rare, ultimate branchlets attenuate at the tip but not pungent, and tetrasporangia in long straight series in the ultimate branchlets. The protein-coding plastid rbcL gene sequence data show that P. pacifica is distinctly different from the superficially similar species, P. morrowii and P. stricta. However, the rbcL sequences of P. pacifica var. pacifica and var. disticha are identical though they have morphological variation.
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Phylogenetic relationships of Polysiphonia (Rhodomelaceae, Rhodophyta) and its relatives based on anatomical and nuclear small-subunit rDNA sequence data
Canadian Journal of Botany, 2001Co-Authors: Han-gu Choi, Myung-sook Kim, Michael D. Guiry, Gary W. SaundersAbstract:The aim of this study was to reassess monophyly of the genus Polysiphonia and determine the phylogenetic affinities of its component lineages among related red algae belonging to the Rhodomelaceae. Our "total evidence" approach, combining 28 anatomical characters and small-subunit ribosomal DNA sequence data for 25 ceramialean algae including 14 species of Polysiphonia sensu lato (including two species of the recently described genus Neosiphonia) and nine related Rhodomelaceae, indicates that Polysiphonia sensu lato consists of three strongly supported clades, Polysiphonia group, Neosiphonia group, and a "multipericentral" group, and a single taxon lineage consisting of Womersleyella setacea. The type species of the genus, Polysiphonia urceolata (= Polysiphonia stricta) from the north Atlantic, formed a distinct clade with Polysiphonia morrowii and Polysiphonia pacifica from the northwest and northeast Pacific, respectively. The Neosiphonia group included Neosiphonia japonica and Neosiphonia savatieri fro...
Brooke Stuercke - One of the best experts on this subject based on the ideXlab platform.
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Consistency of morphological characters used to delimit Polysiphonia sensu lato species (Ceramiales, Florideophyceae): analyses of North Carolina, USA specimens
2014Co-Authors: Brooke Stuercke, Wilson D. FreshwaterAbstract:Polysiphonia sensu lato (including Neosiphonia) is a genus within the red algal order Ceramiales that includes over 200 current species and is distributed throughout the world. The consistency of morphological characters commonly used to distinguish species was tested by analyses of these characters within eight North Carolina, USA, species of P. sensu lato objectively defined by rbcL sequence analysis. Examination of 22 characters found five to be consistent and useful for identifying species: number of pericentral cells, rhizoid–pericentral cell connection, relationship of lateral branches to trichoblasts, spermatangial axes development, and arrangement of tetrasporangia. Character states for the pattern and occurrence of trichoblasts and scar cells, the type of the holdfast, and formation of cicatrigenous branches may also help to strengthen the distinctions among species; although, some of these characters were not uniformly consistent. These morphological findings may be applicable to the study of P. sensu lato from other regions as well. The eight North Carolina species were resolved in a variety of positions within the Polysiphonia sensu lato rbcL tree, and integrated molecular and morphological analyses indicated that two, Polysiphonia denudata and Polysiphonia urceolata, have been historically misidentified
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An integrated taxonomic assessment of North Carolina Polysiphonia (Ceramiales, Rhodophyta) species
2009Co-Authors: Brooke StuerckeAbstract:The rhodomelacean genus Polysiphonia Greville (Ceramiales, Rhodophyta) contains approximately 200 species that are distributed throughout the world’s oceans. Polysiphonia species have been defined by the number of pericentral cells, presence or absence of cortication, nature and arrangement of trichoblasts, origin of branches in relation to trichoblasts, origin of attachment rhizoids, nature of spermatangial branches, number of carpogonial branch cells and arrangement of tetrasporangia. Most systematic studies of Polysiphonia have had a physiological, karyological, morphological, or reproductive basis, but very few have explored molecular characters. In this study, relationships among North Carolina Polysiphonia species were investigated using an integrated taxonomic approach. Thirty-one Polysiphonia samples were collected from various coastal and offshore environments. Analyses of rbcL were used to objectively delimit species collected in North Carolina and the consistency of 22 morphological characters used to identify Polysiphonia species was examined within eight molecularly defined species clades. Phylogenetically informative morphological characters for North Carolina Polysiphonia species included the number of pericentral cells, rhizoid-pericentral cell connection, relationship of lateral branches to trichoblasts, spermatangial axes development, and arrangement of tetrasporangia. The molecular and morphological analyses were used to identify eight North Carolina species, which were found to represent Neosiphonia harveyi, Polysiphonia atlantica, P. breviarticulata, P. denudata sensu Kapraun, P. fucoides, P. scopulorum var. villum, P. subtilissima, and P. urceolata sensu Kapraun. Both rbcL and SSU analyses were used to determine the relationship of North Carolina Polysiphonia species to those collected elsewhere, and these analyses resolved four major clades within Polysiphonia sensu lato. The character states of characters found to be consistent within species were mapped on the rbcL and SSU trees to determine if there were phylogenetically informative morphological characters for the different molecularly defined clades. The clade containing the generitype, P. stricta, was supported by seven morphological characters considered to be taxonomically significant. Two of the resolved major clades had little morphological support, but these clades are probably comprised of heterogeneous mixtures of distinct species whose relationships could not be confidently resolved based upon the limited number of taxa investigated.
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Consistency of Morphological Characters Used to Delimit Polysiphonia Sensu Lato Species (Ceramiales, Florideophyceae): Analyses of North Carolina, USA Specimens
Phycologia, 2008Co-Authors: Brooke Stuercke, D. Wilson FreshwaterAbstract:B. Stuercke & D.W. Freshwater. 2008. Consistency of morphological characters used to delimit Polysiphonia sensu lato species (Ceramiales, Florideophyceae): analyses of North Carolina, USA specimens...
Christine A. Maggs - One of the best experts on this subject based on the ideXlab platform.
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The genera Melanothamnus Bornet & Falkenberg and Vertebrata S.F. Gray constitute well-defined clades of the red algal tribe Polysiphonieae (Rhodomelaceae, Ceramiales)
2017Co-Authors: Pilar Díaz-tapia, Michael J. Wynne, Wilson D. Freshwater, Lynne Mcivor, Heroen Verbruggen, Christine A. MaggsAbstract:Polysiphonia is the largest genus of red algae, and several schemes subdividing it into smaller taxa have been proposed since its original description. Most of these proposals were not generally accepted, and currently the tribe Polysiphonieae consists of the large genus Polysiphonia (190 species), the segregate genus Neosiphonia (43 species) and 13 smaller genera (< 10 species each). In this paper, phylogenetic relationships of the tribe Polysiphonieae are analysed, with particular emphasis on the genera Carradoriella, Fernandosiphonia, Melanothamnus, Neosiphonia, Polysiphonia sensu stricto, Streblocladia and Vertebrata. We evaluated the consistency of 14 selected morphological characters in the identified clades. Based on molecular phylogenetic (rbcL and 18S genes) and morphological evidence, two speciose genera are recognized: Vertebrata (including the type species of the genera Ctenosiphonia, Enelittosiphonia, Boergeseniella and Brongniartella) and Melanothamnus (including the type species of the genera Fernandosiphonia and Neosiphonia). Both genera are distinguished from other members of the Polysiphonieae by synapomorphic characters, the emergence of which could have provided evolutionarily selective advantages for these two lineages. In Vertebrata trichoblast cells are multinucleate, possibly associated with the development of extraordinarily long photoprotective trichoblasts. Melanothamnus has 3-celled carpogonial branches and plastids lying exclusively on radial walls of the pericentral cells, which similarly may improve resistance to damage caused by excessive light. Other relevant characters that are constant in each genus are also shared with other clades. The evolutionary origin of the genera Melanothamnus and Vertebrata is estimated as 75.7–95.78 and 90.7–138.66 Ma, respectively. Despite arising in the Cretaceous, before the closure of the Tethys Seaway, Melanothamnus is a predominantly Indo-Pacific genus and its near-absence from the north-eastern Atlantic is enigmatic. The nomenclatural implications of this work are that 46 species are here transferred to Melanothamnus, six species are transferred to Vertebrata, and 13 names are resurrected for Vertebrata.
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Reappraisal of the type species of Polysiphonia (Rhodomelaceae, Rhodophyta)
European Journal of Phycology, 2000Co-Authors: Myung-sook Kim, Christine A. Maggs, Lynne Mcivor, Michael D. GuiryAbstract:The genus Polysiphonia Greville, nom. cons., has had a long and confused nomenclatural history. At present, Polysiphonia has a wide circumscription, including at least 200 species, but it is heterogeneous in many vegetative and reproductive developmental features. Central to any re-evaluation of the genus is a detailed examination of the type species of Polysiphonia, P. urceolata (Lightfoot ex Dillwyn) Greville, which is conspecific with P. stricta (Dillwyn) Greville. We here report on the vegetative and reproductive morphology of P. stricta, including P. urceolata, based on type and other material from the British Isles. Thalli consist of prostrate and erect ecorticate axes with four pericentral cells, attached by unicellular rhizoids remaining in open connection with pericentral cells. Prostrate axes lack vegetative trichoblasts ; trichoblasts occur seasonally on erect axes. Branch initials are cut off from the subapical cell at intervals of four or five segments in dichotomous and alternating pairs rat...
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SYSTEMATICS AND PHYLOGEOGRAPHY OF THE INVASIVE RED ALGA, Polysiphonia HARVEYI
Journal of Phycology, 2000Co-Authors: Lynne Mcivor, Christine A. Maggs, Michael J. StanhopeAbstract:Polysiphonia harveyi Bailey was first described from Connecticut in 1848 and morphologically similar species, such as P. japonica and P. strictissima, have subsequently been described many times from different localities such as Japan and New Zealand, placing the taxonomy and nomenclature of this morphologically variable species in confusion. Polysiphonia harveyi is regarded as an alien in the British Isles and the north-eastern North Atlantic and is reported to be spreading rapidly. The first confirmed collection of P. harveyi from the British Isles was in 1908; the source of the British introduction remains unknown. In conjunction with breeding data, rbcL sequences for samples of P. harveyi, P. strictissima, P. japonica and P. akkeshiensis collected from New Zealand, Atlantic and Pacific North America, Japan and Europe, reveal that P. harveyi, P. japonica and P. akkeshiensis constitute a single biological species. The correct name for this is P. harveyi, whilst P. strictissima from New Zealand is a sibling species, distinct from P. harveyi. The center of genetic diversity of P. harveyi is in Japan. The original source of the introduced P. harveyi in the British Isles, Europe and Nova Scotia appears to be Hokkaido, Japan. Separate introductions from a single source population into New Zealand and Pacific and Atlantic North America from Honshu, Japan, apparently have occurred.
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Records of adventive marine algae in New Zealand: Antithamnionella ternifolia, Polysiphonia senticulosa (Ceramiales, Rhodophyta), and Striaria attenuata (Dictyosiphonales, Phaeophyta)
New Zealand Journal of Marine and Freshwater Research, 1996Co-Authors: Wendy A. Nelson, Christine A. MaggsAbstract:Abstract Three species of introduced marine macroalgae are reported for Wellington Harbour (North Island, New Zealand). One of these, Polysiphonia senticulosa (Ceramiales, Rhodophyta) is illustrated from New Zealand for the first time, and the known distributional ranges of two species, Striaria attenuata (Dictyosiphonales, Phaeophyta) and Antithamnionella ternifolia (Ceramiales, Rhodophyta), are extended to the North Island.
Tae Oh Cho - One of the best experts on this subject based on the ideXlab platform.
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Discovery of Wilsonosiphonia fujiae (Rhodomelaceae, Rhodophyta) from the Maldives Islands and transfer of Polysiphonia rhizoidea from Hawaiʻi to Wilsonosiphonia
Phytotaxa, 2020Co-Authors: Ga Hun Boo, Tae Oh Cho, Alison R. Sherwood, Sung Min Boo, Mutue Toyota FujiiAbstract:Wilsonosiphonia is a newly described marine algal genus with three species. The genus was previously confused with the widely distributed taxon Polysiphonia, and because of this, the taxonomy and distribution of Wilsonosiphonia is likely underestimated. We report the discovery of a minute filamentous red alga, Wilsonosiphonia fujiae (Rhodophyta) in the Maldives Islands, a taxon which was considered endemic to Brazil. Specimens were collected at Fulhadoo, Goidhoo Atoll and Dhidhdhoo Islands, South Ari Atoll, which are ca. 160 km apart, during January and July, 2019, respectively. Thalli formed dense patches on the upper intertidal in regions of shaded rock. Both mitochondrial cox1 and plastid rbcL sequencing confirmed the occurrence of W. fujiae in the Maldives, which is also in agreement with morphological observations. Based on the low pairwise divergences of COI-5P and rbcL sequences between the Maldives and Brazil specimens, we suggest that W. fujiae is a recently introduced yet cryptogenic species in the Maldives. Additionally, as a result of our phylogenetic analyses, it became evident that sequences from the Hawaiian Islands, which were listed as members of the genus Polysiphonia, represent species-level diversity within the genus Wilsonosiphonia. Based on both morphological characteristics and the COI-5P phylogeny, we here reinstate Polysiphonia rhizoidea from Hawaiʻi and transfer it to Wilsonosiphonia, as W. rhizoidea comb. nov.
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Polysiphonia freshwateri sp. nov. and Polysiphonia koreana sp. nov.: two new species of Polysiphonia (Rhodomelaceae, Rhodophyta) from Korea
European Journal of Phycology, 2015Co-Authors: Danilo E. Bustamante, Boo Yeon Won, Tae Oh ChoAbstract:Polysiphonia sensu lato comprises approximately 200 species, which are currently assigned to several different genera. To date, one of these genera, namely, Polysiphonia, has been reported to have 17 species. Here, we describe for the first time P. freshwateri sp. nov. and P. koreana sp. nov. from Uljin and Ulleung Island, Korea, based on morphological and molecular evidence. Polysiphonia freshwateri sp. nov. and P. koreana sp. nov. are characterized by having the typical Polysiphonia features. Polysiphonia freshwateri sp. nov. is further characterized by having abundant trichoblasts, conspicuous scar cells, and tetrasporangia arranged in spiral series. Polysiphonia koreana sp. nov. is further characterized by having very scarce scar cells placed between two pericentral cells, from which cicatrigenous branches arise. The results of our rbcL sequence analyses support the taxonomic placement of P. freshwateri sp. nov. and P. koreana sp. nov. within Polysiphonia.