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

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

Sinking Organic Particles in the Ocean—Flux Estimates From in situ Optical Devices

Optical particle measurements are emerging as an important technique for understanding the ocean carbon cycle, including contributions to estimates of their downward flux, which sequesters carbon dioxide (CO2) in the deep sea. Optical instruments can be used from ships or installed on autonomous platforms, delivering much greater spatial and temporal coverage of particles in the mesopelagic zone of the ocean than traditional techniques, such as sediment traps. Technologies to image particles have advanced greatly over the last two decades, but the quantitative translation of these immense datasets into biogeochemical properties remains a challenge. In particular, advances are needed to enable the optimal translation of imaged objects into carbon content and sinking velocities. In addition, different devices often measure different optical properties, leading to difficulties in comparing results. Here we provide a practical overview of the challenges and potential of using these instruments, as a step toward improvement and expansion of their applications

Heterogeneity in diagnostic characters across ecoregions: A case study with Botrynema (Hydrozoa: Trachylina: Halicreatidae)

IntroductionBotrynema, a genus of medusozoans in the trachyline family Halicreatidae, currently contains two species: B. brucei and B. ellinorae, distinguished by the presence or absence, respectively, of an apical knob as a diagnostic character. However, no study has corroborated if these taxonomic diagnoses have a biological and evolutionary basis. Therefore, in this study we attempted to address the question “do the two nominal species in the genus Botrynema represent independent phylogenetic lineages, or two phenotypic variants of a single species?MethodsIn this study we took advantage of legacy collections from different research expeditions across the globe from 2000 to 2021 to study the phylogenetics and taxonomy of the genus Botrynema.ResultsB. brucei and B. ellinorae present partially overlapping vertical distributions in the Arctic and as a whole in the Arctic the genus seems to be limited to the Atlantic water masses. The phylogenetic reconstruction based on the concatenated alignment corroborates the validity of the family Halicreatidae and of genus Botrynema as monophyletic groups. However no clear differentiation was found between the two presently accepted species, B. ellinorae and B. brucei.DiscussionBased on the evidence we gathered, we conclude that while the genus Botrynema does contain at least two species lineages, these lineages are not concordant with current species definitions. The species B. ellinorae is reassigned as a subspecies of B. brucei and diagnostic characters are provided

SNAGA, TEORIJA I PRAKSA (Kraft, Theorie und Praxis)

We have developed a global biogeographic classification of the mesopelagic zone to reflect the regional scales over which the ocean interior varies in terms of biodiversity and function. An integrated approach was necessary, as global gaps in information and variable sampling methods preclude strictly statistical approaches. A panel combining expertise in oceanography, geospatial mapping, and deep-sea biology convened to collate expert opinion on the distributional patterns of pelagic fauna relative to environmental proxies (temperature, salinity, and dissolved oxygen at mesopelagic depths). An iterative Delphi Method integrating additional biological and physical data was used to classify biogeographic ecoregions and to identify the location of ecoregion boundaries or inter-regions gradients. We define 33 global mesopelagic ecoregions. Of these, 20 are oceanic while 13 are ‘distant neritic.’ While each is driven by a complex of controlling factors, the putative primary driver of each ecoregion was identified. While work remains to be done to produce a comprehensive and robust mesopelagic biogeography (i.e., reflecting temporal variation), we believe that the classification set forth in this study will prove to be a useful and timely input to policy planning and management for conservation of deep-pelagic marine resources. In particular, it gives an indication of the spatial scale at which faunal communities are expected to be broadly similar in composition, and hence can inform application of ecosystem-based management approaches, marine spatial planning and the distribution and spacing of networks of representative protected areas

Vertical profiles of marine particulates : a step towards global scale comparisons using an Autonomous Visual Plankton Recorder (シンポジウム イメージング技法によるプランクトン研究)

An Autonomous Visual Plankton Recorder (AVPR) was used to record colour in situ images of plankton and other marine particulates at several oligotrophic stations around the world, including a northern hemisphere subtropical open ocean, a northern hemisphere subtropical marginal sea, a southern hemisphere tropical marginal sea, and a polar open ocean. Quantitative analyses and comparisons of particle concentrations, sizes and vertical profiles were possible after identification of optimal image enhancement settings and employment of a specially- developed macro routine in the off-the-shelf image analysis software Image Pro Plus. Such baseline data is invaluable for assessing the effects of surface or near-surface waste water or tailings disposal during deep-sea mining operations in oligotrophic areas. Marine particulate profiles, their relationships to oceanographic parameters and water mass structure, and the resolution-dependent limitations of the system are introduced and discussed

Dinonemertes Laidlaw 1906

Genus Dinonemertes Laidlaw, 1906 Dinonemertes Laidlaw, 1906: 186.Published as part of Kajihara, Hiroshi & Lindsay, Dhugal J., 2010, Dinonemertes shinkaii sp. nov., (Nemertea: Hoplonemertea: Polystilifera: Pelagica) a new species of bathypelagic nemertean, pp. 43-51 in Zootaxa 2429 on page 44, DOI: 10.5281/zenodo.29330