Hiroshi Kawai

Kobe University

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Takeaki Hanyuda

Kobe University

Akira F. Peters

University of Aberdeen

Hideaki Sasaki

Ehime University

Shinya Uwai

Kobe University

Ni Ni Win

Kyushu University

Christophe Vieira

Institute for Basic Science

Mitsunobu Kamiya

Doshisha University

Akio Murakami

Kobe University

J. Mark Cock

Centre National de la Recherche Scientifique

Kathy Ann Miller

University of California, Berkeley

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Centre National de la Recherche Scientifique

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Sorbonne Université

Station Biologique de Roscoff

Kobe University

Hokkaido University

Laboratoire de Biologie Intégrative des Modèles Marins

Université Paris Cité

The University of Tokyo

University of British Columbia

Centre de Gestion Scientifique

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Global biogeography and diversification of a group of brown seaweeds (Phaeophyceae) driven by clade‐specific evolutionary processes

Journal of Biogeography (2021)

Christophe Vieira Frédérique Steen Sofie D’hondt Quinten Bafort L. Tyberghein

Abstract Aim Historical processes that shaped current diversity patterns of seaweeds remain poorly understood. Using Dictyotales, a globally distributed order of brown seaweeds as a model, we test if historical biogeographical and diversification patterns are comparable across clades. Dictyotales contain some 22 genera, three of which, Dictyota , Lobophora and Padina , are exceptionally diverse. Specifically, we test whether the evolutionary processes that shaped the latitudinal diversity patterns in these clades are in line with the tropical conservatism, out‐of‐the‐tropics or diversification rate hypotheses. Location Global coastal benthic marine environments. Taxon Dictyotales (Phaeophyceae). Methods Species diversity was inferred using DNA‐based species delineation, addressing cryptic diversity and circumventing taxonomic problems. A six‐gene time‐calibrated phylogeny, distribution data of 3,755 specimens and probabilistic modelling of geographical range evolution were used to infer historical biogeographical patterns. The phylogeny was tested against different trait‐dependent models to compare diversification rates for different geographical units as well as different thermal affinities. Results Our results indicate that Dictyotales originated in the Middle Jurassic and reach a current peak of species diversity in the Central Indo‐Pacific. Ancestral range estimation points to a southern hemisphere origin of Dictyotales corresponding to the tropical southern Tethys Sea. Our results demonstrate that diversification rates were generally higher in tropical regions, but increased diversification rates in different clades are driven by different processes. Our results suggest that three major clades underwent a major diversification burst in the early Cenozoic, with Dictyota and Padina expanding their distribution into temperate regions while Lobophora retained a predominantly tropical niche. Main conclusions Our results are consistent with both the tropical conservatism hypothesis, in which clades originate and remain in the tropics ( Lobophora ), and the out‐of‐the‐tropics scenario, where taxa originate and expand towards the temperate regions while preserving their presence in the tropics ( Dictyota , Padina ).

10.1111/jbi.14047

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Citations (31)

New records of Peyssonnelia armorica and Peyssonnelia harveyana (Rhodophyta, Gigartinales) from Japan

Phycological Research (2005)

Aki Kato Michio Masuda Hiroshi Kawai

SUMMARY Two species of the crustose red algal genus Peyssonnelia (Gigartinales, Peyssonneliaceae) are reported from Japanese waters for the first time. These species share the following combination of vegetative and reproductive features: thalli with appressed margins, perithallial filaments arising from the whole upper surface of each hypothallial cell (the Peyssonnelia rubra ‐type anatomy), unicellular rhizoids, hypobasal calcification and spermatangia that are produced in double chains (the Peyssonnelia harveyana ‐type spermatangial filament). However, they differ obviously from each other in the hypothallus orientation as seen from below, the perithallus structure in relation to the consistency of the crust, the origin of gonimoblasts and the elevation of the nemathecia. Peyssonnelia armorica is characterized by: (i) hypothallial filaments comprising a polyflabellate layer; (ii) easily separable perithallial filaments in a gelatinous matrix; (iii) gonimoblasts originating exclusively from the auxiliary cell; and (iv) semi‐immersed (slightly elevated) nemathecia. Peyssonnelia harveyana is characterized by: (i) hypothallial filaments arranged in parallel rows; (ii) closely packed perithallial filaments in a firm matrix; (iii) gonimoblsts originating from both the auxiliary cell and the connecting filament; and (iv) conspicuously elevated nemathecia.

Gigartinales

Thallus

Reticulate

10.1111/j.1440-183.2005.00394.x

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Morphology and life history of Coelocladia arctica (Dictyosiphonales, Phaeophyceae), new to Japan*

Phycological Research (1997)

Hiroshi Kawai

SUMMARY The occurrence of Coelocladia arctica Rosenvinge (Dictyosiphonales, Phaeophyceae) is reported for the first time in the Pacific Ocean, from Oshoro, Hokkaido, Japan. The field material was approximately 30 mm in height, up to 300 M‐μn in diameter, 2‐3 times irregularly branched and provided with phaeophycean hairs and plurilocular sporangia. The thallus was composed of several (usually four) large, hyaline, rounded, isodiametric inner cells, with smaller sub‐cortical and pigmented cortical cells. The plurilocular sporangia were 3‐4 celled, often branched, and protruded from the cortical cells, arranged in a crown‐shaped complex. In culture, the plurispores germinated unipolarly leaving an emptied original spore wall, and developed into a branched protonema. Cells of the protonema as well as the erect thallus contained several disc‐shaped chloroplasts with pyrenoids. Uniseriate erect filaments arose from the protonema, then became polystichous and formed branches. Unilocular sporangia were never observed in the field or in cultured material. Erect thalli were formed under culture conditions of 5‐15°C, and developed a thick parenchyma at 5‐10°C, irrespective of the day length.

Pyrenoid

Thallus

Protonema

10.1111/j.1440-1835.1997.tb00074.x

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Citations (1)

Cladosiphon takenoensis sp. nov. (Ectocarpales s.l., Phaeophyceae) from Japan

Phycological Research (2016)

Hiroshi Kawai Takeaki Hanyuda Song‐Ho Kim Yuki Ichikawa Shinya Uwai

SUMMARY The new brown algal species Cladosiphon takenoensis H. Kawai (Chordariaceae, Ectocarpales s.l .) is described from Takeno, Hyogo, Japan based on morphology and DNA sequences. The species is a spring annual, growing on subtidal rocks at more or less exposed sites. It resembles C. umezakii in its gross morphology, and the two often grow together, but is distinguishable from C. umezakii in having a more hairy appearance. Cladosiphon takenoensis has a slimy, cylindrical, multiaxial and sympodial erect thallus, branching once to twice, and is provided with long assimilatory filaments (up to 1.8 mm long, composed of up to 100 cells). Unilocular zoidangia are formed on the basal part of assimilatory filaments. The species is genetically most related to C. umezakii and has the same basic thallus structures, but differs from C. umezakii and other Cladosiphon species in lacking phaeophycean hairs and plurilocular zoidangia of the assimilatory filaments. DNA sequences of the mitochondrial cox 1 and cox 3, chloroplast atp B, psa A, psb A and rbc L genes and the nuclear rDNA ITS2 region support the distinctness of the species. The genus Cladosiphon was paraphyletic in our analyses because the clades of C. okamuranus/C. zosterae and C. takenoensis/C. umezakii were split by Mesogloia vermiculata . However, since the genus‐level taxonomy of Chordariaceae needs considerable revision, we suspend the genus‐level taxonomy of the new species, and tentatively describe it as C. takenoensis .

Thallus

Paraphyly

10.1111/pre.12140

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Citations (7)

Molecular phylogeny of Laminariales (Phaeophyceae) inferred from small subunit ribosomal DNA sequences

Phycological Research (1999)

Sung Min Boo Wook Jae Lee Hwan Su Yoon Atsushi Kato Hiroshi Kawai

Molecular Phylogenetics

10.1111/j.1440-1835.1999.tb00291.x

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Citations (19)

Sexual pheromones and gamete chemotaxis inAnalipus japonicus (Phaeophyceae)

Experientia (1990)

D. Müller Hiroshi Kawai B. Stache E. Fölster Wilhelm Boland

Gamete

Sexual reproduction

Sexual attraction

10.1007/bf01954258

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Citations (15)

The Ectocarpus Genome and Brown Algal Genomics

Advances in botanical research (2012)

J. Mark Cock Lieven Sterck Sophia Ahmed Andrew E. Allen Grigoris D. Amoutzias

10.1016/b978-0-12-391499-6.00005-0

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Citations (18)

Molecular phylogeny of the benthic dinoflagellateCabra matta(Dinophyceae) from Okinawa, Japan

Phycologia (2018)

Aika Yamaguchi Kevin C. Wakeman Mona Hoppenrath Takeo Horiguchi Hiroshi Kawai

Abstract Cabra is a genus of marine heterotrophic thecate dinoflagellates with a peculiar cell shape and thecal plate tabulation. Previous studies suggested it was related to the benthic genus Roscoffia based on morphological features. A previous molecular phylogenetic study using 18S rDNA showed that Roscoffia capitata and members of the family Podolampadaceae formed a well-supported monophyletic group; however, the classification of Cabra remains uncertain. In this study, the first molecular phylogenetic analysis based on 18S rDNA sequence for the genus was performed using specimens of Cabra matta collected in Okinawa, Japan. Molecular phylogeny showed that C. matta formed a clade with R. capitata and the planktonic oceanic members of Podolampadaceae including Podolampas spp. and Blepharocysta sp. This result supported previous studies that inferred the close affinity between Cabra, podolampadaceans and R. capitata based on a very narrow and long 1′ plate, and the diminutive 2′ and 3′ plates, the larger...

Dinophyceae

Dinoflagellate

Molecular Phylogenetics

10.2216/18-7.1

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Citations (5)

The introduction to Japan of the Titan barnacle, Megabalanus coccopoma (Darwin, 1854) (Cirripedia: Balanomorpha) and the role of shipping in its translocation

Biofouling (2009)

Toshiyuki Yamaguchi Romanus Edy Prabowo Yuu Ohshiro Takaki Shimono Diana S. Jones

The Titan Acorn barnacle, Megabalanus coccopoma, a native of the tropical eastern Pacific, has become established in the western Atlantic (Brazil and the northern Gulf of Mexico to the Carolinas), northwestern Europe and the western Indian Ocean (Mauritius), and therefore its dispersal capabilities are well known. This study reports its introduction to Japan and confirms its occurrence in Australia. In an attempt to determine the source of this introduction, phylogeographic techniques, involving cytochrome c oxidase I sequences of various widely separate populations of M. rosa and M. volcano, were utilized. No significant genetic differentiation or haplotype patterns between widely separated populations of each of the three species were found. Lack of such differentiation indicates recent geographical isolation and thus negates a null hypothesis predicting that the occurrence of one of more of these species in Australia was natural.

10.1080/08927010902738048

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Citations (69)

Taxonomic revision of Chordaria flagelliformis (Chordariales, Phaeophyceae) including

SUNG-Ho Kim Hiroshi Kawai

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