Pukia ohtsukai sp. nov., a new species of "cydippid" ctenophore from Japan

A new species of "cydippid" ctenophore, Pukia ohtsukai sp. nov., is described from material collected in Nishino-omote Port, Tanegashima Island, Japan. It can be distinguished from the only other member of the genus by the presence of perradial canals, lack of bilateral diverticula beneath the comb plates, a lower number of comb plates per comb row (19-21), the presence of black pigment patches at the oral ends of the comb rows and around the statocyst, and by the length of the pole plate, which extends only to the aboral tips of the comb rows.OpenAcces

Asociaciones en la zona bentopelágica: el anfípodo Caprella subtilis (Amphipoda: Caprellidae) y la holoturia Ellipinion kumai (Elasipodida: Elpidiidae)

An association between the caprellid amphipod Caprella subtilis Mayer, 1903 and the elpidiid holothurian Ellipinion kumai (Mitsukuri, 1912) was confirmed through in situ submersible capture at 309 m depth in Sagami Bay, central Japan, and through shipboard observations. Information on this association, including behavioural and morphological data on both species, is presented. Information on the taxonomic standing of C. subtilis and related species is also introduced. Furthermore, we record swimming behaviour in the holothurian genus Ellipinion for the first time. We also introduce other biotic associations revealed during studies using submersible vehicles operated by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), including associations between benthopelagic holothurians and mysids, as well as hydrozoan polyps.Este trabajo confirma la asociación entre el anfípodo caprélido Caprella subtilis Mayer, 1903 y la holoturia elasipodida Ellipinion kumai (Mitsukuri, 1912), a partir de la captura in situ, a 309 m de profundidad, con un submarino, y a través de observaciones a bordo, en la Bahía Sagami, zona central de Japón. Se presenta información de esta asociación, incluyendo datos de comportamiento y morfológicos para ambas especies. También se incluye información del estado taxonómico de C. subtilis y especies relacionadas. Además, registramos por primera vez el comportamiento natatorio del género de holoturia Ellipinion. Asimismo, presentamos información de otras asociaciones bióticas reveladas durante estudios en los que se han utilizados vehículos sumergibles dirigidos por la Japan Agency for Marine-Earth Science and Technology (JAMSTEC), incluyendo asociaciones entre holoturias bentopelágicas y misidáceos, así como pólipos de hidrozoos

A new genus and species of the family Pennellidae (Copepoda, Siphonostomatoida) infecting the Pacific viperfish Chauliodus macouni

A new genus and species of pennellid copepod, Protosarcotretes nishikawai n. g., n. sp., is described on the basis of an ovigerous female infecting a Pacific viperfish Chauliodus macouni collected from the deepwaters of Suruga Bay, Japan. The new genus exhibits the most plesiomorphic states in the first to fourth legs of pennellids, and is differentiated from two closely related pennellid genera Sarcotretes and Lernaeenicus by the morphology of the oral appendages. Two species of the genus Lernaeenicus are transferred to the new genus as　Protosarcotretes multilobatus (Lewis, 1959) n. comb. and Protosarcotretes gnavus (Leigh-Sharpe, 1934) n. comb. The host specificity and life cycle of deep-sea pennellids are discussed. Sarcotretes scopeli Jungersen, 1911　and Cardiodectes bellottii (Richiardi, 1882) show low differentiated host-specificity, while P. nishikawai seems　to be limited to the Stomiidae, which are rare hosts of pennellids, in contrast to the Myctophidae family. In the　Pennellidae family, two patterns of the life cycle are found: with or without naupliar stages.CC BY 2.

Identification of microplastics in a large water volume by integrated holography and Raman spectroscopy

Funding Japan Science and Technology Agency SICORP (JPMJSC1705); Natural Environment Research Council (NE/R01227X/1); Kajima Foundation (Overseas research grant); Japan Society for the Promotion of Science (18H03810, 18K13934); Kurita Water and Environment Foundation (17B030).Peer reviewedPublisher PD

Digital In-Line Holography for Large-Volume Analysis of Vertical Motion of Microscale Marine Plankton and Other Particles

Acknowledgements This work is funded by a joint UK-Japan research program (NERC-JST SICORP Marine Sensor Proof of Concept under project code NE/R01227X/1). The authors would like to thank the captain, crew, science party and technical support staff of the R/V Yokosuka cruise YK20-E02. We also thank Dr. Y. Nagai for providing us the foraminifera samples.Peer reviewedPostprin

Phylogenetics of Trachylina (Cnidaria: Hydrozoa) with new insights on the evolution of some problematical taxa

Some of the most interesting and enigmatic cnidarians are classified within the hydrozoan subclass Trachylina. Despite being relatively depauperate in species richness, the clade contains four taxa typically accorded ordinal status: Actinulida, Limnomedusae, Narcomedusae and Trachymedusae. We bring molecular data (mitochondrial 16S and nuclear small and large subunit ribosomal genes) to bear on the question of phylogenetic relationships within Trachylina. Surprisingly, we find that a diminutive polyp form, Microhydrula limopsicola (classified within Limnomedusae) is actually a previously unknown life stage of a species of Stauromedusae. Our data confirm that the interstitial form Halammohydra sp. (Actinulida) is derived from holopelagic direct developing ancestors, likely within the trachymedusan family Rhopalonematidae. Trachymedusae is shown to be diphyletic, suggesting that the polyp stage has been lost independently at least two times within trachyline evolution. Narcomedusae is supported as a monophyletic group likely also arising from trachymedusan ancestors. Finally, some data, albeit limited, suggest that some trachyline species names refer to cryptic species that have yet to be sorted taxonomicall

Association of Thioautotrophic Bacteria with Deep-Sea Sponges

We investigated microorganisms associated with a deep-sea sponge, Characella sp. (Pachastrellidae) collected at a hydrothermal vent site (686 m depth) in the Sumisu Caldera, Ogasawara Island chain, Japan, and with two sponges, Pachastrella sp. (Pachastrellidae) and an unidentified Poecilosclerida sponge, collected at an oil seep (572 m depth) in the Gulf of Mexico, using polymerase chain reaction–denaturing gradient gel electrophoresis (PCR-DGGE) directed at bacterial 16S rRNA gene sequences. In the PCR-DGGE profiles, we detected a single clearly dominant band in each of the Characella sp. and the unidentified Poecilosclerida sponge. BLAST search of their sequences showed that they were most similar (>99% identity) to those of the gammaproteobacterial thioautotrophic symbionts of deep-sea bivalves from hydrothermal vents, Bathymodiolus spp. Phylogenetic analysis of the near-full length sequences of the 16S rRNA genes cloned from the unidentified Poecilosclerida sponge and Characella sp. confirmed that they were closely related to thioautotrophic symbionts. Although associations between sponges and methanotrophic bacteria have been reported previously, this is the first report of a possible stable association between sponges and thioautotrophic bacteria

Multimodal Image and Spectral Feature Learning for Efficient Analysis of Water-Suspended Particles

apan Science and Technology Agency SICORP and Natural Environment Research Council (JST-NERC SICORP Marine Sensor Proof of Concept Grant JPMJSC1705, NE/R01227X/1); JSPS KAKENHI Grant (18K13934 and 18H03810); Sumitomo Foundation: Grant for environmental Research Project (203122). Acknowledgments. The authors thank Dr. T. Fukuba for the support for building the experimental setup. The authors also thank Dr. H. Sawada for providing samples for this work.Peer reviewedPublisher PD

Phylogenetics of Trachylina (Cnidaria: Hydrozoa) with new insights on the evolution of some problematical taxa

This is the published version, also available here: http://dx.doi.org/10.1017/S0025315408001732.Some of the most interesting and enigmatic cnidarians are classified within the hydrozoan subclass Trachylina. Despite being relatively depauperate in species richness, the clade contains four taxa typically accorded ordinal status: Actinulida, Limnomedusae, Narcomedusae and Trachymedusae. We bring molecular data (mitochondrial 16S and nuclear small and large subunit ribosomal genes) to bear on the question of phylogenetic relationships within Trachylina. Surprisingly, we find that a diminutive polyp form, Microhydrula limopsicola (classified within Limnomedusae) is actually a previously unknown life stage of a species of Stauromedusae. Our data confirm that the interstitial form Halammohydra sp. (Actinulida) is derived from holopelagic direct developing ancestors, likely within the trachymedusan family Rhopalonematidae. Trachymedusae is shown to be diphyletic, suggesting that the polyp stage has been lost independently at least two times within trachyline evolution. Narcomedusae is supported as a monophyletic group likely also arising from trachymedusan ancestors. Finally, some data, albeit limited, suggest that some trachyline species names refer to cryptic species that have yet to be sorted taxonomically