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To elucidate the effect of macroalgae blooms on dissimilatory nitrate reduction pathways (denitrification, anammox, and DNRA) in sediments of the hypereutrophic Yatsu tidal flat, eastern Japan, sediment denitrification, anammox, and DNRA rates were measured using a 15N tracer technique at two sites affected and unaffected by macroalgae (Ulva) blooms and in incubation experiments with and without Ulva. Anammox was insignificant at both sites and in both experiments. The denitrification rate was consistently higher than the DNRA rate, and its contributions to the total dissimilatory nitrate reduction were 82% and 85% at sites affected and unaffected by Ulva, respectively. In a sediment incubation experiment with Ulva, the contribution of DNRA had increased to approximately 30% on day 7, which is when the sulfide concentration was the highest. Sulfide produced by sulfate reduction during macroalgae blooms inhibited denitrification and did not change the DNRA, and consequently increased the DNRA contribution. On day 21, after reaching the peak sulfide concentration during the late macroalgae collapse, the DNRA contribution decreased to 15%. These results indicated that the DNRA contribution was greater during the macroalgae blooms than at the collapse, although denitrification dominated DNRA regardless of the macroalgal status. Therefore, vigorous macroalgae cover and sulfide production under the macroalgae cover had an important impact on the nitrogen dynamics. [ABSTRACT FROM AUTHOR]

Summary: A new red alga from Japan, Dasya japonovillosa, is described. This new species and D. enomotoi, both of which have elongated axes densely covered with numerous soft monosiphonous filaments, may have been misidentified as D. villosa by previous investigators in Japan. Dasya villosa differs from D. japonovillosa and D. enomotoi in the distinct five pericentral cells in transverse sections and palisade‐like tetrasporangial cover cells. The new species is distinguished from several similar species by the combination of the following: an elongated axis (to 65 cm), subdichotomously divided axes and polysiphonous branches, indistinct pericentral cells in transverse sections except near the apices, and the presence of enlarged, inner cortical cells, radially arranged numerous soft monosiphonous filaments, three‐celled carpogonial branches, four tetrasporangia in each fertile segment of the stichidia, and one (rarely two) tetrasporangial cover cell that is not elongated longitudinally and rarely divided transversely. [ABSTRACT FROM AUTHOR]

We collected the deep-water species Rhodymenia prostrata (Rhodymeniaceae, Rhodophyta), for the first time in nearly 50 years, from the type locality off Mageshima Island, Japan. Our combined rbcL, cox1 and 28S rDNA analyses suggested that R. prostrata belongs in the genus Halopeltis but is distinct from all other Halopeltis species. However, the binomial Halopeltis prostrata already exists and hence a new epithet was required. Consequently, we propose the new name Halopeltis tanakae for R. prostrata based on morpho-anatomical and molecular analyses. The occurrence of small intercalating cells in H. tanakae is congruent with the generic concept of Halopeltis. Halopeltis tanakae is characterized by a procumbent thallus, crispate blades, cystocarps lacking basal constrictions, cystocarps primarily on blade margins, and mucilaginous strands in cystocarp cavities. Halopeltis tanakae is the second representative of the genus to be reported from the northwestern Pacific. [ABSTRACT FROM AUTHOR]

We describe herein a new species of Sheathia from Chiba Prefecture, Japan (previously attributed to S. arcuata) based on morphological studies and molecular analyses of rbcL and COI-5P DNA sequences. We assign the binomial Sheathia yoshizakii sp. nov. to this new entity. The rbcL and COI-5P analyses suggest that S. yoshizakii is distinct from other Sheathia species. Sheathia yoshizakii is characterized by homocortication, a carpogonium with clavate to lanceolate trichogyne, and exerted carposporophytes. Although S. yoshizakii is distinguished from other Sheathia species by rare production of secondary fascicle and relatively long carpogonial branch, more than seven carposporophytes per whorl, and frequently exerted carposporophytes, these morphological characters are variable and consistent with the general circumscription of S. arcuata. Sheathia yoshizakii is the first Sheathia species confirmed by DNA sequence data in Japan. [ABSTRACT FROM AUTHOR]

SUMMARY: Genetic analysis of type material of various Ulva species has shown that many names have been misapplied. DNA sequences of two of the specimens on the lectotype sheet of U. australis from South Australia showed that U. australis is conspecific with specimens called U. pertusa from Japan. However, type material of U. pertusa has not been sequenced, nor have other type specimens with type localities in Japan and Australia, including U. conglobata f. conglobata and U. conglobata f. densa from the former, and U. laetevirens and U. spathulata from the latter. To determine if these names have been correctly applied, targeted DNA sequencing of the rbcL gene was performed on (i) the lectotype specimen of U. laetevirens, (ii) the lectotype and two syntype specimens of U. pertusa, (iii) the lectotype and two syntype specimens of U. congoblata f. conglobata and (iv) two specimens on the holotype sheet of U. conglobata f. densa. In addition, high‐throughput sequencing (HTS) analysis was carried out on an isotype specimen of U. spathulata. Phylogenetic analysis of the resulting rbcL gene sequences supports the taxonomic conclusions that U. laetevirens, U. pertusa and U. spathulata are synonyms of U. australis, and U. conglobata f. conglobata and U. conglobata f. densa represent a single separate and distinct species, U. conglobata. These genetic data contribute to the taxonomy of Ulva and further demonstrate that analyzing DNA from type material is the only currently known reliable method to correctly apply names in this genus. [ABSTRACT FROM AUTHOR]

The present-day genetic structure of macroalgal species reflects both geographical history and oceanic circulation patterns as well as anthropogenic introduction across native ranges. To precisely understand the genetic diversity and how the factors shape the current population structure of Gloiopeltis furcata sensu lato, we determined the mitochondrial 5' end of cytochrome c oxidase subunit I (COI-5P) sequences for 677 individuals sampled from 67 sites spanning almost the entire distribution range in Korea and Japan. Results from the phylogenetic analysis and haplotype distribution revealed eleven distinct lineages within G. furcata s.l. along the Korea-Japan coastal areas and displayed divergent phylogeographic patterns among lineages. Despite the closely related lineages distributed in same habitats as high rocky intertidal zone, they display different phylogeographic patterns among lineages. The populations from the south of Korea-Japan harbored the highest genetic diversity and unique endemism in comparison with other populations in the distribution range. This could be the evidence of southern refugia for G. furcata s.l. in the Northwest (NW) Pacific and the recent migration from native to introduced region. The reason is that an exceptional distribution pattern was found high genetic diversity in Hakodate of Japan where is the northern location in the NW Pacific. Our results imply the contemporary influence on the distribution due to current circulation pattern and anthropogenic effects. These phylogeographic findings provide the important insight into cryptic species diversity and the detailed distribution pattern of Gloiopeltis in the NW Pacific. [ABSTRACT FROM AUTHOR]

SUMMARY The rare red alga Schimmelmannia (Schimmelmanniaceae, Acrosymphytales) from Japan was taxonomically re‐examined in this study. Japanese Schimmelmannia has previously been identified as S. plumosa (Setchell) I.A.Abbott. However, Japanese Schimmelmannia and S. plumosa have approximately 5 and 1.9% of genetic distance in mitochondrial cox1 and chloroplast rbcL sequences, respectively. They also differ morphologically in the numbers of periaxial cells and auxiliary cell branches indicating that they are distinct species. Based on molecular phylogenetics and morphology, S. benzaiteniana is distinguishable from other Schimmelmannia species, except for S. bollei Montagne which lacks a detailed description. Since S. bollei has been reported only from the North Atlantic coast of Africa, we assumed that it is distinct from the Japanese species. We, therefore, described the Japanese species as a new species, S. benzaiteniana. [ABSTRACT FROM AUTHOR]

The constitution of Laurencia snackeyi (Weber-van Bosse) Masuda (Ryukyu-sozo in Japanese) from three locations, Minna Island, Sesoko Island and Kayo Coast in Okinawa Prefecture, Japan, is reported. This species produced snyderane-type sesquiterpenes, palisadin A (1), palisadin B (2) and aplysistatin (3) as characteristic metabolites. The species name of "Laurencia luzonensis Masuda", which has previously been reported in several papers, should be revised to L. snackeyi. [ABSTRACT FROM AUTHOR]

• Dulse (Palmaria sp.) is an abundant and underused resource in Hokkaido Prefecture, Japan. • Dulse is rich in xylan which is the source of XOS used as a functional food material. • XOS were enzymatically produced from the dulse xylan rich fraction in a high conversion ratio. • This is the first report to investigate the effective enzymatic condition for dulse XOS production. Red alga dulse (Palmaria sp.) has xylan with a small amount of cellulose and less lignin, hence these characteristics may provide some advantages in the enzymatic production of xylooligosaccharides (XOS). To evaluate dulse xylan as XOS source, we prepared xylan rich fraction (DXRF) and attempted XOS production using commercial enzymes. 13.8% of xylan rich fraction (DXRF: containing 52.2% of xylan) was obtained from dried dulse powder. We then evaluated the hydrolysis products of two commercial enzymes, revealing that hydrolysate of Hemicellulase amano 90 contained less xylose. The effective XOS production by the enzyme was evaluated in terms of enzyme dose, DXRF concentration and reaction period, showing that 66.6% of XOS was obtained from DXRF with the hydrolysis rate of 82% under the following condition: 54 U Hemicellulase amano 90, 10 mg/ml DXRF, pH 4.5, 50 °C for 24 h. These results indicated that red algae xylan is suitable for XOS source. [ABSTRACT FROM AUTHOR]

A new red alga, Dasya enomotoi, is described from Japan. This species is characterized by having a large thallus consisting of an elongated axis and many, radially arranged, polysiphonous branches both of which are heavily corticated and densely covered with numerous, soft monosiphonous filaments. It is distinguished from several similar species by the combination of the following: (i) indistinct pericentral cells in transverse sections except near the apices, (ii) the presence of enlarged, inner cortical cells, (iii) radially arranged adventitious monosiphonous filaments, (iv) three-celled carpogonial branches, (v) six (sometimes five) tetrasporangia in each fertile segment of the stichidia, and (vi) three tetrasporangial cover cells that are not elongated longitudinally and usually not divided transversely. This species may have been identified as D. villosa Harvey by previous investigators in Japan. [ABSTRACT FROM AUTHOR]

We isolated the conchocelis strain OHN-1 from a long linear blade growing in a natural population of bladed Bangiales in Ohara, Chiba Prefecture, the Boso Peninsula in Japan, which is affected by the warm Kuroshio Current. The strain was identified as Neoporphyra kitoi based on the RUBISCO spacer sequences and phylogenetic analysis of the rbc L gene. Under identical laboratory cultures, the growth and pigment contents of the strain were compared with those of Neopyropia yezoensis f. narawaensis , which is the main cultivar currently cultivated in Japan. The conchocelis maturity of OHN-1 was remarkably higher than that of strain HG-4 of Neopy. yezoensis f. narawaensis at higher temperatures of 25 and 30 °C among the 5 temperature conditions (10, 15, 20, 25, 30 °C). The growth of the gametophytic blade was significantly higher in OHN-1 than in HG-4 at each examined temperature (15, 20, 25 °C). In particular, the OHN-1 blades at the highest temperature of 25 °C grew the largest until 3 weeks of culture, although the blades grew larger over 3 weeks with decreasing temperature. Moreover, the photosynthetic pigment contents, especially the phycoerythrin content, were significantly higher in OHN-1 than in HG-4. These results demonstrate that Neoporphyra kitoi has potential as a candidate species for marine crops with high temperature tolerance despite faster blade maturity. • The strain OHN-1 was identified as Neoporphyra kitoi based on molecular analyses. • Blade growth was significantly higher in OHN-1 than in a cultivated strain HG-4 at higher temperatures. • The pigment contents of OHN-1 were also significantly higher than those of HG-4. • N. kitoi has potential as a candidate species for marine crops with high temperature tolerance. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Ulva meridionalis, a green macroalgae, is one of the causal species for green tides in Japan and spread into the coast of China. During this research, we sequenced the complete mitochondrial genome of U. meridionalis. The mitogenome is 62,887 bp in length, including 28 encoding genes and 29 tRNA genes. Compared with the Ulva species from mitogenome, the gene order and organization of this mitogenome are similar to most of other determined Ulva mitogenomes, with the nucleotide base composition of A 33.6%, T 32.2%, C 16.2%, and G 18.0%. Phylogenetic analysis shows U. meridionalis is closely related to Ulva flexuosa. [ABSTRACT FROM AUTHOR]

Inferring phylogeographic patterns of macroalgal species is essential for understanding the population structure and for the conservation of macroalgal species. In this study, the phylogeographic patterns of two co-distributed macroalgal species along the coast of Korea and Japan, Pachymeniopsis lanceolata and Pachymeniopsis elliptica, were analyzed. Pachymeniopsis lanceolata (215 specimens from 36 sites) and P. elliptica (138 specimens from 24 sites), using the plastid rbcL gene, are characterized by fifteen and six haplotypes, respectively. Mitochondrial COI-5P gene sequences revealed a low variation for both species. An analysis of molecular variance (AMOVA), pairwise FST comparisons, and haplotype networks based on the rbcL data suggest a weak genetic differentiation of both species. The shared haplotypes (P. lanceolata: LR01; P. elliptica: ER01) found in the entire sampling range indicate that these two Pachymeniopsis species can disperse over long distances along the coast of Korea and Japan. Despite the similar phylogeographic pattern, our results suggest that P. lanceolata has a higher genetic diversity, with a wider distribution along the Korean Peninsula than P. elliptica. Moreover, it is adapted to low sea surface temperatures and survived in more of the available habitats during periods of climatic change, whereas P. elliptica is less adaptable and more susceptible to environmental disturbance. This phylogeographic study provides a rationale for the conservation of the wild Pachymeniopsis population. [ABSTRACT FROM AUTHOR]

The chemical composition of three Laurencia spp., Laurencia sp., L. okamurae and L. saitoi , which were collected from the Seto Inland Sea of Japan, has been examined. Laurencia sp. collected from the coast of Matoba Park, Takehara, Hiroshima Prefecture, contained a brominated chamigrane-type sesquiterpene (1), named matobol, as the main metabolite. The structure of matobol was determined as (+)-(2 R ,3 R ,6 R ,10 S)-2,10-dibromochamigr-7(14)-en-3-ol (1). This is the first time that the optically active 1 has been isolated from Laurencia. On the other hand, L. okamurae from the coast of Ikunoshima Island, Hiroshima Prefecture, produced laurinterol (2) that is a known cyclolaurane-type sesquiterpene characteristic to this species in Japan. L. saitoi from the coast of Matoba Park contained a known bromoallenic C 15 -acetogenin, neolaurallene (3). [Display omitted] • The constitution of Laurencia spp. collected from the Seto Inland Sea of Japan was investigated. • This is the first report of the isolation of (+)-2,10-dibromochamigr-7(14)-en-3-ol (matobol) from Laurencia sp. • Chemical and morphological characteristic of Laurencia sp. are discussed. [ABSTRACT FROM AUTHOR]

Systematic studies were undertaken on the Caloglossa continua (Okammura) King et Puttock complex from Japan, Singapore, and Austriala, based on morphology and reproductive compatibility. Specimens from Japan had two to six cell rows derived from a nodel axial cell, at the margin opposite the branch, whereas those from Austraila possessed only a single cell now. Specimens from Singapore formed one to four cell rows per nodal axial cell and always contained at least one single cell row on any one thallus. These differences were maintained in cultural materials over a range of temperagtures or salinities. Type material of C. continua had the same morphology as the Japanese specimens in this study. Carpospores discharged from the Japanese isolate germinated at 10°C, whereas those from Singapore and Australia died at this temperature. In hybridization experiments, the Japanese entity was completely nonfertile with both the Singaporean and Australian isolates. Many pseudocystocarps were produced in the crossing between the make from Australia and the female from Singapore, although the reciprocal combination did not produce any such structures. On the basis of the discontinuous morphology coupled with the complete reproducture isolation, the entiries from Singapore and Australia are described here as C. monosticha sp. nov. The entiries with multiple cell rows likely expanded their geographic range from tropical regions, where the majority of Caloglossa species are now distributed, to high-latitude regions, and such an expansion would be associated with acquining low-temperature tolerance. [ABSTRACT FROM AUTHOR]

This article presents information related to morphological features of Japanese Ptilota (Ceramiales, Rhodophyta). The most conspicuous diagnostic feature for the identification of individual specimens is the growth manner of first-order branches (traditionally referred to as pinnae) on the primary axis. Ptilota serrata and P. phacelocarpoides have two types of branches, those with determinate growth becoming leaflet-like branchlets and those with indeterminate growth becoming pinnate branches. On the other hand, P. plumosa and P. filicina have two branches with indeterminate growth which are dissimilar in size .

The article focuses on conspecificity of two Japanese laurencia species: laurencia okamurae and laurencia japonica. Laurencia japonica Yadama, which is from Chiba Prefecture, Pacific coast is shown to be taxonomically synonymous with laurencia okamurae Yadama. Laurencia japonica seems to be an early seasonal form, with a thicker and tougher frond than the late-seasonal form, which is typical of laurencia okamurae.

The article describes the sexual reproductive organs of Bostrychia flagellifera (Ceramiales, Rhodophyta) from Japan. Bostrychia flagellifera is monoecious, and the spermatangial sorus is found to form at the terminal portion of fertile branches in conjunction with a procarp. The axial cell divides longitudinally to produce four to five pericentral cells, called as primary parent cells. Each primary parent cell divides to produce secondary parent cells, each of which divide successively to produce tertiary parent cells. The tertiary parent cells produce 1-2 spermatangia.

Reports on a study by researchers from Japan on the examination of the type of specimen of Laurencia glandulifera found in the Rijksherbarium, Leiden, The Netherlands. Description of the type of specimen found; Comparison between L. glandulifera from L. paniculata.

Describes a new genus Kurogia for the family Delesseriaceae in Hokkaido, Japan. Observation on the structure of the thallus; Mode of development; Pattern of apical segmentation of the blade.

The red alga Laurencia nipponica Yamada (Rhodo- melaceae, Ceramiales) is known to contain several chemical races, each of which is characterized by a particular, major halogenated secondary metabolite. Both field-collected and cultured plants of a population of this species found recently at Shikanoshima Island, Fukuoka Prefecture, southern Japan, produced C15 bromoethers, (3E)-laureatin and (3E)-iso- laureatin, and sesquiterpenoids, 2, 10-dibromo-3- chloro-9-hydroxy-α chamigrene and 2, 10-dibromo-3- chloro-ct-chamigrene. Laurencia nipponica can be referred to as a turther chemical race that is char- acterized by the production of two C[sup15] bromoethers, (3E)-taureatin and (3E)-isolaureatin, and a sesqui- terpenoid, 2,10-dibromo-3-chloro-9-hydroxy-a- chamigrene as major compounds. [ABSTRACT FROM AUTHOR]

Laurencia omaezakiana Masuda, sp. nov. (Ceramiales, Rhodophyta) is described from Japan. It is characterized by the following set of features: (I) the production of four periaxial cells from each vegetative axial cell; (ii) a shift in branching from distichous to spiral; (iii) the presence of projecting superficial cortical cells near the apices of branches; (iv) the presence of longitudinally oriented secondary pit-connections between contiguous superficial cortical cells; (v) the presence of lenticular thickenings in the walls of medullary cells; (vi) the occurrence of 1-2 corps en cerise in each superficial cortical cell and a single corps en cerise in each trichoblast cell; and (vii) a parallel arrangement of tetrasporangia. Furthermore, it produces a characteristic triterpenoid (enshuo), which has not been detected in other species of Laurencia, as a major halogenated secondary metabolite. A synoptical key to the 23 species of Laurencia growing in Japan is given. Laurericia ceylanica J. Agardh and Laurencia heterocs'ada Harvey are excluded from the Japanese marine algal flora. The `latter is a distinct species from Laurencia filiformis (C. Agardh) Montagne. [ABSTRACT FROM AUTHOR]

Two populations of the red alga Laurencia majuscula (Harvey) Lucas (Rhodomelaceae, Ceramiales) from Taketomi Island and Hateruma Island, the Ryukyu Islands, Japan, have been characterized on the basis of both morphological features and halogenated Secondary metabolite content. These populations have smaller and more slender thalli than those of other regions. Furthermore, the populations contain two chamigrane-type sesquiterpenoids, (2R,3R,5S)-5- acetoxy-2-bromo-3-chlorochamigra-7( 14),9-then-8- one and (2R,3R)-2-bromo-3-chlorochamigra-7(14). 9-dien-8-one, and a laurane-type sesquiterpenoid, debromoisolaurinterol, as secondary metabolites which are different from those previously reported from other populations. These results are consistent with the concept of 'chemical races' within a single species of Laurencia. [ABSTRACT FROM AUTHOR]

Morphological and hybridization experiments were performed on Caloglossa leprieurii (Montagne) J. Agardh collected from Japan, Singapore and Australia in order to evaluate taxonomic characters of this species. Within C. leprieurii at least four mating groups were recognized from the Indo-Pacific region. These mating groups could be characterized by the blade width at the internode and the cell-row numbers on the opposite side derived from the first axial cell at the main axis, though these properties showed a certain variability even in the same plant under both field and culture conditions. The phylogenetic relationship and geographic distribution of the four mating groups are discussed. [ABSTRACT FROM AUTHOR]

Focuses on a study on Spirocladia loochooensis, a newly collected species with a combination Rhodomelaceae--Rhodophyta in Japan. Description on the holotype specimen; Pattern on the formation of tetrasporangial stichidia; Hypothesis that the species is accommodated in the genus Spirocladia BOERGESEN.

The article presents information on the scientific name of a delesseriacean red alga "Numehanori." "Numehanori" in Japanese is distributed in Hokkaido and northern Honshu and was first described by researcher W.H. Harvey from Hakodate as Delesseria serrulata. Later, the alga was renamed as Delesseria violacea by researcher J.G. Agardh and then combined with Apoglossum as A.violaceum by J. Agardh. Nomenclatural investigation of the papers concerned revealed that the correct name of "Numehanori" is Delesseria serrulata.

Intensive algal sampling was conducted from 2012 to 2017 in the Tomioka Peninsula, Amakusa-Shimoshima Island (the East China Sea, Japan), yielding a total of 293 benthic macroalgal taxa, of which 63% were red algae, 16% were brown algae, and 19% were green algae. The majority (69%) of species were previously recorded only for the tropics and/or subtropics, whereas 31% of species were recorded for temperate latitudes. Among all species of algae found from 2012 to 2017 in the Tomioka Peninsula, 163 species (56%) were newly identified species for Amakusa-Shimoshima Island, including six taxa, which were recorded in Japan for the first time. Comparison of the current data from the Amakusa-Shimoshima Island with those of nearby tropical regions suggested that the recent marine flora of the Amakusa-Shimoshima Island was more closely affiliated with the flora of a warm-temperate region. Moreover, we found that the benthic flora of the Tomioka Peninsula was significantly changed between the 1950s (Segawa & Yoshida 1961) and 2012–2017. For example, the species diversity was increased by two times, mainly at the expense of red and green algae, and the biogeographic status of the benthic flora was changed from the flora of a cold-temperate region to the flora of a warm-temperate region, which could be attributed to an introduction of red algae from the tropics of South East Asia and widespread opportunistic green algae, as well as the disappearance of cold-water brown algae. Collectively, our data suggested that these changes were driven by the global warming effect on the ocean. [ABSTRACT FROM AUTHOR]