116 research outputs found
Detailed Mapping of Hydrothermal Vent Fauna: A 3D Reconstruction Approach Based on Video Imagery
Active hydrothermal vent fields are complex, small-scale habitats hosting endemic fauna that changes at scales of centimeters, influenced by topographical variables. In previous studies, it has been shown that the distance to hydrothermal fluids is also a major structuring factor. Imagery analysis based on two dimensional photo stitching revealed insights to the vent field zonation around fluid exits and a basic knowledge of faunal assemblages within hydrothermal vent fields. However, complex three dimensional surfaces could not be adequately replicated in those studies, and the assemblage structure, as well as their relation to abiotic terrain variables, is often only descriptive. In this study we use ROV video imagery of a hydrothermal vent field on the southeastern Indian Ridge in the Indian Ocean. Structure from Motion photogrammetry was applied to build a high resolution 3D reconstruction model of one side of a newly discovered active hydrothermal chimney complex, allowing for the quantification of abundances. Likewise, the reconstruction was used to infer terrain variables at a scale important for megabenthic specimens, which were related to the abundances of the faunal assemblages. Based on the terrain variables, applied random forest model predicted the faunal assemblage distribution with an accuracy of 84.97 %. The most important structuring variables were the distances to diffuse- and black fluid exits, as well as the height of the chimney complex. This novel approach enabled us to classify quantified abundances of megabenthic taxa to distinct faunal assemblages and relate terrain variables to their distribution. The successful prediction of faunal assemblage occurrences further supports the importance of abiotic terrain variables as key structuring factors in hydrothermal systems and offers the possibility to detect suitable areas for Marine Protected areas on larger spatial scales. This technique works for any kind of video imagery, regardless of its initial purpose and can be implemented in marine monitoring and management
sFDvent: A global trait database for deepâsea hydrothermalâvent fauna
Motivation: Traits are increasingly being used to quantify global biodiversity patterns,
with trait databases growing in size and number, across diverse taxa. Despite growâ
ing interest in a traitâbased approach to the biodiversity of the deep sea, where the
impacts of human activities (including seabed mining) accelerate, there is no single reâ
pository for species traits for deepâsea chemosynthesisâbased ecosystems, including
hydrothermal vents. Using an international, collaborative approach, we have compiled
the first globalâscale trait database for deepâsea hydrothermalâvent fauna â sFDâ
vent (sDivâfunded trait database for the Functional Diversity of vents). We formed a
funded working group to select traits appropriate to: (a) capture the performance of
vent species and their influence on ecosystem processes, and (b) compare traitâbased
diversity in different ecosystems. Forty contributors, representing expertise across
most known hydrothermalâvent systems and taxa, scored species traits using online
collaborative tools and shared workspaces. Here, we characterise the sFDvent daâ
tabase, describe our approach, and evaluate its scope. Finally, we compare the sFDâ
vent database to similar databases from shallowâmarine and terrestrial ecosystems to
highlight how the sFDvent database can inform crossâecosystem comparisons. We
also make the sFDvent database publicly available online by assigning a persistent,
unique DOI.
Main types of variable contained: Six hundred and fortyâsix vent species names,
associated location information (33 regions), and scores for 13 traits (in categories:
community structure, generalist/specialist, geographic distribution, habitat use, life
history, mobility, species associations, symbiont, and trophic structure). Contributor
IDs, certainty scores, and references are also provided.
Spatial location and grain: Global coverage (grain size: ocean basin), spanning eight
ocean basins, including vents on 12 midâocean ridges and 6 backâarc spreading
centres.
Time period and grain: sFDvent includes information on deepâsea vent species, and
associated taxonomic updates, since they were first discovered in 1977. Time is not
recorded. The database will be updated every 5 years.
Major taxa and level of measurement: Deepâsea hydrothermalâvent fauna with speâ
ciesâlevel identification present or in progress.
Software format: .csv and MS Excel (.xlsx).This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited
Ocean Species Discoveries 1â12 â A primer for accelerating marine invertebrate taxonomy
Discoveries of new species often depend on one or a few specimens, leading to delays as researchers wait for additional context, sometimes for decades. There is currently little professional incentive for a single expert to publish a stand-alone species description. Additionally, while many journals accept taxonomic descriptions, even specialist journals expect insights beyond the descriptive work itself. The combination of these factors exacerbates the issue that only a small fraction of marine species are known and new discoveries are described at a slow pace, while they face increasing threats from accelerating global change. To tackle this challenge, this first compilation of Ocean Species Discoveries (OSD) presents a new collaborative framework to accelerate the description and naming of marine invertebrate taxa that can be extended across all phyla. Through a mode of publication that can be speedy, taxonomy-focused and generate higher citation rates, OSD aims to create an attractive home for single species descriptions. This Senckenberg Ocean Species Alliance (SOSA) approach emphasises thorough, but compact species descriptions and diagnoses, with supporting illustrations and with molecular data when available. Even basic species descriptions carry key data for distributions and ecological interactions (e.g., host-parasite relationships) besides universally valid species names; these are essential for downstream uses, such as conservation assessments and communicating biodiversity to the broader public
The Application of DNA Barcodes for the Identification of Marine Crustaceans from the North Sea and Adjacent Regions
During the last years DNA barcoding has become a popular method of choice for molecular specimen identification. Here we present a comprehensive DNA barcode library of various crustacean taxa found in the North Sea, one of the most extensively studied marine regions of the world. Our data set includes 1,332 barcodes covering 205 species, including taxa of the Amphipoda, Copepoda, Decapoda, Isopoda, Thecostraca, and others. This dataset represents the most extensive DNA barcode library of the Crustacea in terms of species number to date. By using the Barcode of Life Data Systems (BOLD), unique BINs were identified for 198 (96.6%) of the analyzed species. Six species were characterized by two BINs (2.9%), and three BINs were found for the amphipod species Gammarus salinus Spooner, 1947 (0.4%). Intraspecific distances with values higher than 2.2% were revealed for 13 species (6.3%). Exceptionally high distances of up to 14.87% between two distinct but monophyletic clusters were found for the parasitic copepod Caligus elongatus Nordmann, 1832, supporting the results of previous studies that indicated the existence of an overlooked sea louse species. In contrast to these high distances, haplotype-sharing was observed for two decapod spider crab species, Macropodia parva Van Noort & Adema, 1985 and Macropodia rostrata (Linnaeus, 1761), underlining the need for a taxonomic revision of both species. Summarizing the results, our study confirms the application of DNA barcodes as highly effective identification system for the analyzed marine crustaceans of the North Sea and represents an important milestone for modern biodiversity assessment studies using barcode sequence
A new genus of Ectinosomatidae (Copepoda, Harpacticoida) from sublittoral sediments in Ubatuba, SĂŁo Paulo State, Brazil, including an updated key to genera and notes on Noodtiella Wells, 1965
Both sexes of a new genus and species of Ectinosomatidae (Copepoda, Harpacticoida) from sublittoral sediments collected on the inner continental shelf in Ubatuba, SĂŁo Paulo State (Brazil) are described in detail. Chaulionyx gen. n. (type species: C. paivacarvalhoi sp. n.) differs from all known genera in the presence of a conspicuous bifid spine on the prehensile P1 endopod. It can be differentiated from other genera with a prehensile endopod (Halophytophilus Brian, 1919; Bradyellopsis Brian, 1925; Klieosoma Hicks & Schriever, 1985) by the presence of distinctive subrectangular middorsal pores on the urosomites and the unarmed male sixth legs. The genus Lineosoma Wells, 1965 is recognized as a paraphyletic taxon and relegated to a junior subjective synonym of Noodtiella Wells, 1965. Arenosetella pectinata Chappuis, 1954a is removed from its floating position in Ectinosomoides Nicholls, 1945, transferred to the genus Noodtiella as N. pectinata comb. n. and considered the senior subjective synonym of N. toukae Mitwally & Montagna, 2001. Dichotomous keys are provided for the identification of the 18 valid species of Noodtiella and the 21 valid genera of the family Ectinosomatidae. Halophytophilus aberrans Wells & Rao, 1987 is placed species incertae sedis in the family
A new genus of Ectinosomatidae (Copepoda, Harpacticoida) from sublittoral sediments in Ubatuba, SĂŁo Paulo State, Brazil, including an updated key to genera and notes on Noodtiella Wells, 1965
Both sexes of a new genus and species of Ectinosomatidae (Copepoda, Harpacticoida) from sublittoral sediments collected on the inner continental shelf in Ubatuba, SĂŁo Paulo State (Brazil) are described in detail. Chaulionyx gen. n. (type species: C. paivacarvalhoi sp. n.) differs from all known genera in the presence of a conspicuous bifid spine on the prehensile P1 endopod. It can be differentiated from other genera with a prehensile endopod (Halophytophilus Brian, 1919; Bradyellopsis Brian, 1925; Klieosoma Hicks & Schriever, 1985) by the presence of distinctive subrectangular middorsal pores on the urosomites and the unarmed male sixth legs. The genus Lineosoma Wells, 1965 is recognized as a paraphyletic taxon and relegated to a junior subjective synonym of Noodtiella Wells, 1965. Arenosetella pectinata Chappuis, 1954a is removed from its floating position in Ectinosomoides Nicholls, 1945, transferred to the genus Noodtiella as N. pectinata comb. n. and considered the senior subjective synonym of N. toukae Mitwally & Montagna, 2001. Dichotomous keys are provided for the identification of the 18 valid species of Noodtiella and the 21 valid genera of the family Ectinosomatidae. Halophytophilus aberrans Wells & Rao, 1987 is placed species incertae sedis in the family
First record of Clausidium (Copepoda, Clausidiidae) from Brazil: a new species associated with ghost shrimps Neocallichirus grandimana (Gibbes, 1850) (Decapoda, Callianassidae)
A new clausidiid copepod was found living in galleries of ghost shrimps Neocallichirus grandimana (Gibbes, 1850) in Natal, Brazil. The new species resembles to Clausidium senegalense Humes, 1957 and C. vancouverense (Haddon, 1912) in the armature of P2âP5 of the female, and shares with C. senegalense similar segmentation and armature of the antenna and maxilla of the female. Nevertheless, it can be easily distinguished from its congeners by the unique characteristics observed in the antenna, maxilliped and first leg of males, as well as by the anal somite, maxillule and maxilliped of the females. This new species extends the group distribution to the Southwest Atlantic and represents the first record of the genus in Brazil. A key for the identification of the species based on females of Clausidium is provided
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