Language：English   Publishing type：Research paper (scientific journal)  

DOI： doi.org/10.1007/s10811-021-02661-3

Language：English   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.3391/bir.2022.11.2.14

Language：English   Publishing type：Research paper (scientific journal)  

Among the distinctive members of the brown algal family Scytosiphonaceae is the genus Hydroclathrus, which is primarily distinguished by its clathrate (net-like) appearance. Hydroclathrus, despite being seasonal and species poor, is a conspicuous floristic component in many tropical to warm temperate coasts. However, compared with other closely related genera, such as Colpomenia and Rosenvingea, Hydroclathrus remains poorly known; its taxonomy remains problematic, as information on the molecular phylogenetic relationships of the species is still scarce. We attempted to bridge these gaps by describing the diversity and molecular phylogeny of Hydroclathrus based on morphological and genetic (mitochondrial cox1 and cox3 and plastidial psaA and rbcL genes) data. We recognised four Hydroclathrus species: H. clathratus, H. stephanosorus, H. tenuis and H. minutus sp. nov., which is morphologically cryptic to H. tenuis. A new clathrate genus, Tronoella ryukyuana gen. & sp. nov., is also erected based on specimens from southern Japan. Tronoella is primarily distinguished from Hydroclathrus in possessing (1) highly convoluted thalli with branches that are sometimes slightly twisted and/or interadhesive; (2) siphonous protrusions that grow randomly and in various directions, later on becoming perforated branches with revolute margins; and (3) plurangia that are firmly coherent and massive. Our results highlight the need to re-evaluate the identity of the species reported as H. clathratus and H. tenuis and underscore the need to re-examine the taxonomy and systematics of the family Scytosiphonaceae.

DOI： 10.2216/17-68.1

Language：English   Publishing type：Research paper (scientific journal)  

The systematics of the Laurencia complex was investigated using a taxon-rich data set including the chloroplast ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit (rbcL) gene only and a character-rich data set combining mitochondrial cytochrome oxidase 1 (COI-5P), the rbcL marker, and the nuclear large subunit of the ribosomal operon (LSU). Bayesian and ML analyses of these data sets showed that three species hitherto placed in the genus Laurencia J.V.Lamour. were not closely related to Laurencia s. str. Laurencia caspica Zinova & Zaberzhinskaya was the sister group of the remaining Osmundea Stackh. species, L. crustiformans McDermid joined Palisada and L. flexilis Setch. consisted of an independent lineage. In light of these results a new genus, Ohelopapa F.Rousseau, Martin-Lescanne, Payri & L.Le Gall gen. nov., is proposed to accommodate L. flexilis. This new genus is morphologically characterized by four pericentral cells in each vegetative axial segment; however, it lacks ‘corps en cerise’ in cortical cells and secondary pit connections between cortical cells, which are characteristic of Laurencia. Three novel combinations are proposed to render the classification closer to a natural system: Ohelopapa flexilis (Setch.) F.Rousseau, Martin-Lescanne, Payri & L.Le Gall comb. nov., Osmundea caspica (Zinova & Zaberzhinskaya) Maggs & L.M.McIvor comb. nov. and Palisada crustiformans (McDermid) A.R.Sherwood, A.Kurihara & K.W.Nam comb. nov.

DOI： 10.5852/ejt.2017.269

Language：English   Publishing type：Research paper (scientific journal)  

Liagora japonica is a red algal species distributed in temperate regions of Japan. This species has not been collected from its type locality on the Pacific coast of Japan since 1927 and seems to have become extinct in this area. For molecular characterization of L. japonica, we extracted DNA from the topotype material of L. japonica collected in 1927, analyzed seven genes using Illumina next-generation sequencing, and compared these data with sequences from modern samples of similar red algae collected from the Japan Sea coast of Japan. Both morphological and molecular data from modern samples and historical specimens (including the lectotype and topotype) suggest that the specimens from the Pacific and Japan Sea coasts of Japan should be treated as a single species, and that L. japonica is phylogenetically separated from the genus Liagora. Based on the phylogenetic results and examination of reproductive structures, we propose Otohimella japonica gen. et comb. nov., characterized morphologically by diffuse carposporophytes, undivided carposporangia, and involucral filaments initiated only from the cortical cell on the supporting cell.

DOI： 10.1371/journal.pone.0158944

Language：English   Publishing type：Research paper (scientific journal)  

Six intraspecific lineages (Lineages 1-6) of Asparagopsis taxiformis have been previously established based on mitochondrial cox2-cox3 intergenic spacer and a partial cox1 sequences. 'Lineage 2' (L2) was suggested to be a recent introduction to the Mediterranean Sea, but its source population has not yet been identified. In order to clarify the nature of northwestern Pacific populations, we performed extensive sampling in Japan (60 individuals from 16 locations) and molecular phylogenetic analyses based on mitochondrial sequences. Sixteen additional individuals, collected from eight locations in the Indo-Pacific, Caribbean, and Mediterranean regions, were also analyzed. Combined sequence analyses revealed that the Japanese populations only consisted of L2. Out of 19 combined haplotypes identified within L2, two are shared between Japan and the Mediterranean Sea and the Hawaiian Islands, and 12 were identified as endemic to Japan. Genetic analyses of population differentiation suggested that Japanese populations are genetically isolated from the Mediterranean and the Hawaiian populations. A genetic disjunction appears to separate two subpopulations within Japan: one between Toi and Kagoshima and the other between Ojikajima Island and Kagoshima in the Kyushu area.

DOI： 10.1111/pre.12126

Language：English   Publishing type：Research paper (scientific journal)  

The green microalga, Pyramimonas parkeae (Prasinophyceae) has an ejective organelle containing a coiled ribbon structure resembling the ejectisome in Cryptophyta. This structure is discharged from the cell by a stimulus and extends to form a tube-like structure, but the molecular components of the structure have not been identified. Tricine-SDS-PAGE analysis indicated that the ribbon-like structure of P. parkeae contains some proteins and low molecular acidic polymers. Edman degradation, LC/MS/MS analyses and immunological studies demonstrated that their proteins are core histones (H3, H2A, H2B and H4). In addition, monosaccharide composition analysis of the ribbon-like structures and degradation by lysozyme strongly indicated that the ribbon-like structure consist of β (1-4) linked polymers containing N-acetyl-glucosamine. Purified polymers and recombinant histones formed glob-like or filamentous structures. Therefore we conclude that the ribbon-like structure of P. parkeae mainly consists of a complex of core histones (H3, H2A, H2B and H4) and polymers containing N-acetyl-glucosamine, and suggest to name the ejective organelle in P. parkeae the "histrosome" to distinguish it from the ejectisome in Cryptophyta.

DOI： 10.1016/j.protis.2015.08.003

Language：English   Publishing type：Research paper (scientific journal)  

Scytosiphon lomentaria (Scytosiphonaceae, Ectocarpales) is believed to include some cryptic species, particularly in the Pacific. We attempted to delimit these species in Japan using mitochondrial cox1 and cox3 and nuclear ITS2 and the second intron of the centrin gene (cetn-int2). Fifty-three cox1+cox3 mitotypes, 26 ITS2 ribotypes and 45 cetn-int2 haplotypes were found in 107 samples collected from 33 localities in Japan. Based on phylogenetic analyses, similar sequence types were grouped into ten mitogroups, eight ribogroups and six cetn-int2 haplogroups (sequence-type groups). From the molecular trees and combinations of the mito-, ribo- and haplogroups, three cryptic species were apparent (Groups I-III). Group I, widely distributed on Pacific coasts, was highly supported by all molecular trees, whereas Groups II (North Pacific) and III (Northwestern Pacific and Australasia) were more closely related to each other. However, sequence-type-group combinations that would be characteristic of hybrids between Groups II and III were not detected, suggesting no gene flow between the two Groups. Further investigations of an additional 127 sympatrically growing plants supported the absence of gene flow between Groups II and III. Four samples did not belong to any of the Groups I-III and possibly represent additional species.

DOI： 10.1111/pre.12091

Language：English   Publishing type：Research paper (scientific journal)  

Molecular phylogenetic analyses based on plastid-encoded rbcL and mitochondrial cox3 gene sequences, in combination with morphological observations, revealed the existence of the following four bistratose Padina species previously unreported from Australian coasts: Padina calcarea Ni-Ni-Win, S.G.A.Draisma, W.F.Prud'homme van Reine & H.Kawai, characterised by its bright yellow-orange inferior thallus surface and chalky white, heavily calcified superior surface, and the presence of hairlines only on the inferior surface; P. macrophylla Ni-Ni-Win, M.Uchimura & H.Kawai, characterised by a moderately calcified thallus with broad, depressed hairlines on the inferior surface and narrow, not depressed hairlines on the superior surface, those hairlines that are largely spaced on each surface; P. moffittiana I.A.Abbott & Huisman, characterised by lightly calcified thalli with narrow, slightly depressed hairlines that are distributed in alternate sequence between the two surfaces at unequal distances, and broad reproductive sori in one or two rows in the fertile zone; and P. okinawaensis Ni-Ni-Win, S.Arai, M.Uchimura & H.Kawai, characterised by heavily calcified thalli, except at the hairlines, which form an alternation of uncalcified furrows and calcified glabrous zones on the inferior surface. With the addition of these four species, 13 Padina species are known from Australia.

DOI： 10.1071/SB13025

Language：English   Publishing type：Research paper (scientific journal)  

Rhodachlya hawaiiana Kurihara, J. A. West, Conklin et A.R. Sherwood sp. nov. is described based on cultured material from the island of Hawaii as the second member of the genus Rhodachlya. The pit plug ultrastructure of this alga is characterized by the presence of inner and outer cap layers but lacking a cap membrane between the layers, which is a diagnostic feature of the order Rhodachlyales and the genus Rhodachlya. Morphologically, R. hawaiiana is distinctive from R. madagascarensis in vegetative cell dimensions, frequency of colorless hair cell formation, and spore germination pattern. Rhodachlya hawaiiana and R. madagascarensis are also distinguishable by their nuclear SSU rRNA gene sequence divergence (p-distance = 0.0064), which is comparable to other species-level divergences among members of the Nemaliophycidae.

DOI： 10.7872/crya.v33.iss1.2011.021

Language：English   Publishing type：Research paper (scientific journal)  

A new brown alga Petalonia tatewakii sp. nov. (Scytosiphonaceae) is described from the Hawaiian Islands based on morphological observations and phylogenetic analyses of DNA sequences of the chloroplast-encoded rbcL gene and the ITS1-5.8S-ITS2 region of the nuclear ribosomal cistron. The thalli are linear and complanate, up to 15 cm in length and 0.8 cm in width with rhizoidal filaments in the medulla. This species is morphologically distinguishable from other Petalonia species by having ascocysts among plurilocular zoidangia. Molecular phylogenetic analyses revealed that samples of P. tatewakii form a distinct clade that is sister to the clade of P. binghamiae (J. Agardh) Vinogradova. All our collections of Hawaiian Petalonia from the main Hawaiian Islands were assigned to P. tatewakii.

DOI： 10.2216/10-75.1

Language：English   Publishing type：Research paper (scientific journal)  

Sixty-one Hawaiian algal specimens corresponding to members of the tribe Amansieae (Amansia and Osmundaria) were compared through DNA sequence analysis. Short DNA barcode-like sequences of mitochondrial cytochrome c oxidase subunit I (COI) and universal plastid amplicon (UPA) markers were obtained for as many of the specimens as possible, and a subset of specimens was also used for amplification and sequencing of the nuclear small-subunit rRNA (SSU) gene for phylogenetic inference in a broader taxonomic context. Statistical parsimony analysis of the COI and UPA markers for A. glomerata produced relationships among the samples that were largely congruent with each other, although the UPA marker was more conserved. The COI marker yielded three lineages, and nucleotide divergences for these three lineages were intermediate to those typically reported for intraspecific and interspecific comparisons, suggesting that they represent either incipient species or a complex of closely related species. The COI and UPA sequences demonstrated little to no divergence for Osmundaria obtusiloba and the taxon referred to as Amansia fimbrifolia. In contrast, specimens identified as A. daemelii were identical in sequence to lineage 3 sequences of A. glomerata, and it is recommended that this taxon no longer be included in species lists for the Hawaiian flora. Phylogenetic reconstruction based on the SSU gene was largely unresolved, indicating that this marker may be of limited utility for this purpose in this group of algae, but a small amount of nucleotide variation was found for samples of A. glomerata.

DOI： 10.1111/j.1440-1835.2010.00591.x

Language：English   Publishing type：Research paper (scientific journal)  

A total of 290 florideophyte samples from the Hawaiian Rhodophyta Biodiversity Survey, spanning 17 orders of red algae, were sequenced for the mitochondrial COI DNA barcode, partial nuclear LSU rRNA gene, and plastid UPA rRNA marker. COI was A-T rich (> 60% overall) in comparison to the two rRNA markers, and was also the least conserved, with the third codon position showing the most substitution. Saturation was reached at F84 distances of approximately 0.11 for COI and 0.30 for LSU, but not at all for UPA, and some differences were found when orders or groups of families were individually examined. Rates of sequencing success for the three markers ranged from 46.8% for COI to 64.7% for UPA and 79.6% for LSU, indicating substantial differences in ease of data acquisition. Concatenation of marker sequences starting with the least saturated marker (UPA), and adding in order of degree of saturation (UPA+LSU, followed by UPA+LSU+COI) resulted in a strong increase in bootstrap support with neighbor-joining analysis, indicating that some phylogenetic utility can be gained from barcode-like sequences that are obtained for biodiversity surveys.

Language：English   Publishing type：Research paper (scientific journal)  

Sequences of the nuclear internal transcribed spacer 1 (ITS1) region and the chloroplast rbcL gene were obtained from 86 specimens of Ulva (including "Enteromorpha" ) from five of the main Hawaiian Islands. These 86 specimens were divided into 11 operational taxonomic units (OTUs) based on analyses of primary sequence data and comparisons of ITS1 secondary structure. Of the 11 OTUs, six have not previously been reported from anywhere in the world. Only three represented exact sequence matches to named species (Ulva lactuca L., syn. U. fasciata Delile; U. ohnoi Hiraoka et Shimada); two others represented exact sequence matches to unnamed species from Japan and New Zealand. Of the 12 species names currently in use for Hawaiian Ulva, only one, U. lactuca (as U. fasciata), was substantiated. General morphology of the specimens did not always correspond with molecular OTUs; for example, reticulate thallus morphology, previously considered diagnostic for the species U. reticulata Forssk., was expressed in thalli assigned to U. ohnoi and to one of the novel OTUs. This finding confirms a number of recent studies and provides further support for a molecular species concept for Ulva. These results suggest that Ulva populations in tropical and subtropical regions consist of species that are largely unique to these areas, for which the application of names based on types from temperate and boreal European and North American waters is inappropriate. Ulva ohnoi, a "green tide" species, is reported from Hawaii for the first time.

DOI： 10.1111/j.1529-8817.2010.00860.x

Language：English   Publishing type：Research paper (scientific journal)  

A molecular phylogenetic study of red algal parasites commonly found in the Northwestern Pacific and the Hawaiian Islands was undertaken. Four species, Benzaitenia yenoshimensis Yendo, Janczewskia hawaiiana Apt, J. morimotoi Tokida, and Ululania stellata Apt et Schlech (Ceramiales), are parasitic on rhodomelacean species belonging to the tribes Chondrieae and Laurencieae. Although Janczewskia and Ululania are classified in the same tribes as their host species, the taxonomic placement of Benzaitenia has been controversial. To infer the phylogenetic positions of these parasites and to clarify the relationships between the parasites and their hosts, phylogenetic analyses of partial nuclear SSU and LSU rRNA genes and the cox1 gene were performed. The SSU rRNA gene analyses clearly show that both Janczewskia species are positioned within the Laurencia s. str. clade with their host species, while Benzaitenia and Ululania are placed in the Chondrieae clade. According to these analyses, J. hawaiiana and U. stellata are not sister to their current hosts; in contrast, B. yenoshimensis and J. morimotoi are closely related to their current hosts. These data suggest that J. hawaiiana and U. stellata have likely evolved from species other than their current hosts and have switched hosts at some point in their evolutionary history. Likelihood ratio tests do not support the monophyly of J. hawaiiana and J. morimotoi, suggesting multiple origins of parasitism within Laurencia s. str.

DOI： 10.1111/j.1529-8817.2010.00834.x

Language：English   Publishing type：Research paper (scientific journal)  

The Hawaiian red algal flora is diverse, isolated, and well studied from a morphological and anatomical perspective, making it an excellent candidate for assessment using a combination of traditional taxonomic and molecular approaches. Acquiring and making these biodiversity data freely available in a timely manner ensures that other researchers can incorporate these baseline findings into phylogeographic studies of Hawaiian red algae or red algae found in other locations. A total of 1,946 accessions are represented in the collections from 305 different geographical locations in the Hawaiian archipelago. These accessions represent 24 orders, 49 families, 152 genera and 252 species/subspecific taxa of red algae. One order of red algae (the Rhodachlyales) was recognized in Hawaii for the first time and 196 new island distributional records were determined from the survey collections. One family and four genera are reported for the first time from Hawaii, and multiple species descriptions are in progress for newly discovered taxa. A total of 2,418 sequences were generated for Hawaiian red algae in the course of this study--915 for the nuclear LSU marker, 864 for the plastidial UPA marker, and 639 for the mitochondrial COI marker. These baseline molecular data are presented as neighbor-joining trees to illustrate degrees of divergence within and among taxa. The LSU marker was typically most conserved, followed by UPA and COI. Phylogenetic analysis of a set of concatenated LSU, UPA and COI sequences recovered a tree that broadly resembled the current understanding of florideophyte red algal relationships, but bootstrap support was largely absent above the ordinal level. Phylogeographic trends are reported here for some common taxa within the Hawaiian Islands and include examples of those with, as well as without, intraspecific variation. The UPA and COI markers were determined to be the most useful of the three and are recommended for inclusion in future algal biodiversity surveys. Molecular data for the survey provide the most extensive assessment of Hawaiian red algal diversity and, in combination with the morphological/anatomical and distributional data collected as part of the project, provide a solid baseline data set for future studies of the flora. The data are freely available via the Hawaiian Algal Database (HADB), which was designed and constructed to accommodate the results of the project. We present the first DNA sequence reference collection for a tropical Pacific seaweed flora, whose value extends beyond Hawaii since many Hawaiian taxa are shared with other tropical areas.

DOI： 10.1186/1471-2229-10-258

Language：English   Publishing type：Research paper (scientific journal)  

A paucity of diagnostic morphological characters for identification and high morphological plasticity within the genera Eucheuma and Kappaphycus has led to confusion about the distributions and spread of three introduced eucheumoid species in Hawaii. Entities previously identified as E. denticulatum, K. alvarezii, and K. striatum have had profound negative effects on Oahu's coral reef ecosystems. The use of molecular tools to aid identification of algal species has been promising in other morphologically challenging taxa. We used three molecular markers (partial nuclear 28S rRNA, partial plastid 23S rRNA, and mitochondrial 5′ COI) and followed a DNA barcoding-like approach to identify Eucheuma and Kappaphycus samples from Hawaii. Neighbor-joining analyses were congruent in their separation of Eucheuma and Kappaphycus, and the resulting clusters were consistent with those revealed for global comparisons with the mitochondrial cox2-3 spacer and GenBank data. Based on these results, new insights were revealed into the distribution of these groups in Hawaii.

DOI： 10.1007/s10811-009-9404-2

Language：English   Publishing type：Research paper (scientific journal)  

Background. Organization and presentation of biodiversity data is greatly facilitated by databases that are specially designed to allow easy data entry and organized data display. Such databases also have the capacity to serve as Laboratory Information Management Systems (LIMS). The Hawaiian Algal Database was designed to showcase specimens collected from the Hawaiian Archipelago, enabling users around the world to compare their specimens with our photographs and DNA sequence data, and to provide lab personnel with an organizational tool for storing various biodiversity data types. Description. We describe the Hawaiian Algal Database, a comprehensive and searchable database containing photographs and micrographs, geo-referenced collecting information, taxonomic checklists and standardized DNA sequence data. All data for individual samples are linked through unique accession numbers. Users can search online for sample information by accession number, numerous levels of taxonomy, or collection site. At the present time the database contains data representing over 2,000 samples of marine, freshwater and terrestrial algae from the Hawaiian Archipelago. These samples are primarily red algae, although other taxa are being added. Conclusion. The Hawaiian Algal Database is a digital repository for Hawaiian algal samples and acts as a LIMS for the laboratory. Users can make use of the online search tool to view and download specimen photographs and micrographs, DNA sequences and relevant habitat data, including georeferenced collecting locations. It is publicly available at http://algae.manoa.hawaii.edu.

DOI： 10.1186/1471-2229-9-117

Language：English   Publishing type：Research paper (scientific journal)  

The morphology of utricles was critically studied in order to elucidate the species composition of prostrate Codium in Japan. Utricle morphology, such as length, diameter, shape of apical portions, presence or absence of hairs (or hair-scars) and alveolate ornamentation, are shown to characterize the clades recognized in our previous molecular analysis. These molecular and morphological congruences indicate that these morphological features reflect the phylogeny of Codium. The prostrate Codium in Japan was classified into the following five species: C. arabicum Kützing, C. capitulatum Silva & Womersley, C. dimorphum Svedelius, C. hubbsii Dawson, C. lucasii Setchell.

Language：English   Publishing type：Research paper (scientific journal)  

Two species of Dasya in the Dasyaceae (Ceramiales, Rhodophyta) are reported from Bonin Islands, southern Japan. Dasya murrayana Abbott et Millar, new to Japan, is characterized by the following set of features: the tufted habit (up to 30 erect axes developing from a basal disc), small-sized (6-10 mm high and 350-500 μm in diameter in the middle region), thinly but completely corticated axes, rigid and incurved pseudolaterals forming corymbose heads at the apices of axes and branches, the absence of adventitious monosiphonous filaments, a large number of tetrasporangial stichidia and spermatangial branches per fertile pseudolateral and slender spermatangial branches (35-45 μm in diameter). Dasya boninensis Masuda, Kurihara et Kogame, sp. nov. is characterized by short but thick (10-30 mm high and 600-1000 μm in diameter at the middle portion), heavily corticated axes, indistinct pericentral cells except for the upper portion in transverse sections, soft, straight pseudolaterals and adventitious monosiphonous filaments densely covering the axis and branches, a small number of tetrasporangial stichidia and spermatangial branches per fertile pseudolateral, thick spermatangial branches (65-90 μm in diameter), and short-necked cystocarps. A dichotomous key to the taxa found in Japanese waters is given.

DOI： 10.1111/j.1440-1835.2007.00454.x

Language：English   Publishing type：Research paper (scientific journal)  

Three species in the red algal order Ceramiales, Dasya longifila Masuda et Uwai (Dasyaceae), Endosiphonia horrida (C. Agardh) P. Silva (Rhodomelaceae) and Laurencia flexilis Setchell (Rhodomelaceae), are reported from Japan for the first time, and their morphological features are described along with taxonomic comments. Our findings point to the northernmost limit of geographic distribution of these species in the north-western Pacific. Dasya longifila is characterized by small, sparsely corticated axes, long pseudolaterals in which intercalary cell divisions take place, and a small number of tetrasporangial stichidia and spermatangial branches per fertile pseudolateral. Endosiphonia horrida is characterized by frequently anastomosing branches that form a bush-like tuft without a percurrent axis, inner cortical cells becoming the same length as the axial and periaxial cells, and luxuriously developed, unbranched trichoblasts. Laurencia flexilis is characterized by numerous cartilaginous rigid axes developing from a basal disc without creeping branches, the production of 4 periaxial cells per vegetative segment and the absence of longitudinally oriented secondary pit-connections between contiguous superficial cortical cells.

DOI： 10.1111/j.1440-1835.2006.00433.x

Language：English   Publishing type：Research paper (scientific journal)  

Three species of the red algal genus Herposiphonia (Ceramiales, Rhodomelaceae) found in Japan are described, and taxonomic features of the genus are discussed. Herposiphonia crassa Hollenberg is reported from Japan for the first time and is characterized by thick axes (200-350 μm in diameter) and determinate branches (100-200 μm in diameter), relatively short determinate laterals (400-1200 μm in length) with a large number of periaxial cells (15-19 per segment) and three (occasionally two or four) vigorously developed (1.8-2.5 mm in length by 50-75 μm in diameter basally) trichoblasts on each determinate lateral. Herposiphonia elongata Masuda et Kogame is also reported from Japan for the first time and is characterized by the conspicuous thickening growth of cystocarp-bearing branches and spermatangial branches with an elongated sterile tip. Some newly found features of Herposiphonia fissidentoides (Holmes) Okamura are presented: the rhizoid production from the central portion of parental periaxial cells in addition to the distal end, virtual absence of vegetative trichoblasts, production of procarpial trichoblasts and spermatangial branches on fertile determinate branches on short indeterminate laterals, cystocarps sometimes with a short spur, and extremely large tetrasporangia.

DOI： 10.1111/j.1440-1835.2006.00431.x

Language：English   Publishing type：Research paper (scientific journal)  

In order to elucidate possible relationships among tetrasporophytic and gametophytic species of the red algal genus Galaxaura (Galaxauraceae, Nemaliales), we studied some tetrasporophytic and gametophytic species from Japanese waters, using morphological data, partial sequences of the large subunit of the RUBISCO (rbcL) gene and the nuclear rDNA internal transcribed spacer 1 (ITS1). Two morphologically similar species, G. apiculata Kjellman (tetrasporophytic species whose tetrasporangia are reported for the first time) and G. hystrix Kjellman (gametophytic species). Both of these were originally described from Japan and shared identical rbcL and ITS1 sequences. We conclude that these two algae constitute a single species, although their internal structures are distinct (particularly the shape of the cortical cells). Galaxaura hystrix is subsumed in G. apiculata and we provide an emended description of the species. Structural dimorphism among tetrasporophytic and gametophytic individuals within a single species was also confirmed in two additional species, G. falcata Kjellman and G. papillata Kjellman, whose type localities are also in Japan.

DOI： 10.1080/09670260400005542

Event date： 2025.1

Language：Japanese   Presentation type：Symposium, workshop panel (nominated)  

Venue：Faculty of Agriculture, Kyushu University   Country：Japan  

Event date： 2024.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都大学農学部（吉田キャンパス）   Country：Japan  

海産エビの主要生産国であるベトナムでは、国内生産量の約7割が集約養殖が可能なバナメイエビで占められているが、生産性に重点を置く集約型養殖では、汚泥や富栄養化した用水の未処理放流による環境影響が懸念されており、その解決策として多栄養段階複合養殖の技術開発が進んでいる。本発表では、ベトナム・カントー大学との国際共同研究の一環として、魚類と海藻類を組み込んだ強化型生物ろ過槽を用いた超高密度（初期密度500尾/m^3）の飼育実験結果について報告した。

Event date： 2023.11

Language：English   Presentation type：Oral presentation (invited, special)  

Venue：Vietnam National University-Ho Chi Minh City (VNUHCM), Institute for Nanotechnology (INT)   Country：Viet Nam  

Event date： 2023.1

Language：English   Presentation type：Poster presentation  

Venue：Newcastle University, England   Country：United Kingdom  

Event date： 2022.12 - 2023.6

Language：Japanese  

Venue：TKP東京駅カンファレンスセンター（Webハイブリッド）   Country：Japan  

Event date： 2020.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：科学技術館サイエンスホール   Country：Japan  

Event date： 2020.8

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Viet Uc Hotel, Ben Tre Province, Vietnam   Country：Viet Nam  

Event date： 2016.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：日本歯科大学   Country：Japan  

Event date： 2015.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学箱崎キャンパス   Country：Japan  

Type：Academic society, research group, etc. 

Type：Competition, symposium, etc. 

Number of participants：250

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Number of participants：800

Audience：Infants,　Schoolchildren,　Junior students,　High school students

Type：Other

Audience：Infants,　Schoolchildren,　Junior students,　High school students

Type：Other