BACKGROUND: The deep (> 200 m) ocean floor is often considered to be a refugium of biodiversity; many benthic marine animals appear to share ancient common ancestry with nearshore and terrestrial relatives. Whether this pattern holds for vertebrates is obscured by a poor understanding of the evolutionary history of the oldest marine vertebrate clades. Hagfishes are jawless vertebrates that are either the living sister to all vertebrates or form a clade with lampreys, the only other surviving jawless fishes.
RESULTS: We use the hagfish fossil record and molecular data for all recognized genera to construct a novel hypothesis for hagfish relationships and diversification. We find that crown hagfishes persisted through three mass extinctions after appearing in the Permian ~ 275 Ma, making them one of the oldest living vertebrate lineages. In contrast to most other deep marine vertebrates, we consistently infer a deep origin of continental slope occupation by hagfishes that dates to the Paleozoic. Yet, we show that hagfishes have experienced marked body size diversification over the last hundred million years, contrasting with a view of this clade as morphologically stagnant.
CONCLUSIONS: Our results establish hagfishes as ancient members of demersal continental slope faunas and suggest a prolonged accumulation of deep sea jawless vertebrate biodiversity.

In regions close to the continental shelf edge, the transfer of particulate organic carbon (POC) within the food web and with downward fluxes contributes to the long-term storage of carbon in deep basins. The degradation of POC by heterotrophic prokaryotes is one of the key indices of biological productivity and ecosystem functioning. Here we present data on the spatial and vertical distribution of the total bacterial abundance, fraction of high DNA-content and particle-associated bacteria, and POC concentration. Additionally we determined environmental parameters (temperature, salinity, turbidity, fluorescence and dissolved oxygen concentration). The data were collected in the Vilkitsky Strait and along two transects from the outer shelf of the Laptev Sea to the adjacent continental slope region of the Arctic Ocean in August-September 2018. Principal component analysis was used to reveal relationships between environmental factors and bacterial characteristics. Total bacterial abundance (BA) was positively correlated with seawater fluorescence, dissolved oxygen concentration and POC, but negatively linked to depth and salinity. The percentage of both particle-associated bacteria (%PAB) and bacteria with high DNA concentration (%HDNA) were positively linked to depth and salinity. The data obtained may be useful for a comprehensive assessment of the state of ecosystems in the vicinity of the Arctic continental slope under changing environmental conditions, as well as for studying microbial input in the carbon cycle.

UNASSIGNED: This dataset contributes to the knowledge of macro- and megafaunal Mollusca associated with a range of benthic habitat types in the South Orkney Islands, Antarctica, an exceptionally diverse region of the Southern Ocean. The information presented is derived from Agassiz trawl samples collected on the archipelago\'s shelf plateau and slope, within and outside of the South Orkney Islands Southern Shelf Marine Protected Area (SOISS MPA). Sampling was conducted in the framework of the British Antarctic Survey/SCAR \"South Orkneys - State of the Antarctic Ecosystem\" (SO-AntEco) project aboard RRS James Clark Ross during expedition JR15005 in Austral summer 2016. This dataset is published by the British Antarctic Survey under the licence CC-BY 4.0. We would appreciate it if you could follow the guidelines from the SCAR Data Policy (SCAR 2023) when using the data. If you have any questions regarding this dataset, do not hesitate to contact us via the contact information provided in the metadata or via data-biodiversity-aq@naturalsciences.be. Issues with the dataset can be reported at https://github.com/biodiversity-aq/data-publication/. This dataset is part of the Biodiversity, Evolution and Adaptation Project of the Environmental Change and Evolution Program of the British Antarctic Survey. The cruise report of the expedition is available at https://www.bodc.ac.uk/resources/inventories/cruise_inventory/reports/jr15005.pdf.
UNASSIGNED: We report occurrences of Mollusca from individual samples taken with a 2 m-wide Agassiz trawl (AGT) in the framework of the February - March 2016 research expedition JR15005 of RRS James Clark Ross to the SOISS MPA and adjacent shelf and slope areas. Of 78 successful AGT deployments, 44 trawls at depths ranging from 235-2194 m yielded living Mollusca, totalling 2276 individuals, 67 morphospecies and 163 distributional records. One hundred and fifteen empty shells were also collected and recorded in the dataset. Three morphospecies (one Bivalvia and two Gastropoda) were sampled exclusively as empty shells, yielding a total of 70 morphospecies and 2391 specimens represented in the dataset. All specimens were preserved in 96% undenatured ethanol and are stored as vouchers in the collections of the British Antarctic Survey (BAS), Cambridge, United Kingdom. The publication of this dataset aims at increasing the knowledge on the biodiversity, abundance and geographical and bathymetric distribution of larger-sized epi- and shallow infaunal Mollusca of the South Orkney Islands.

Mesoscale eddies have been reported to have a substantial impact on the distribution of phytoplankton through the regulation of environmental variables in the open ocean. However, the influence of warm eddies on phytoplankton in continental slopes remains largely unknown. To reveal the impact of mesoscale eddies within slope regions, we conducted a field investigation of picophytoplankton on the northern slope of the South China Sea during an anticyclonic warm eddy propagation. We observed different picophytoplankton distribution patterns. Synechococcus dominated the picophytoplankton community in the Kuroshio-affected eddy core rather than the previously reported Prochlorococcus, and Prochlorococcus dominated outside the eddy in the shelf. In addition, through further vertical study of typical layers, we found that the influence of warm eddy varied in different layers. Analysis of the mechanisms indicated that the distributions were attributed to warm eddy-induced nutrients and light variations and the physical processes in it.

Polychaetes are one of the most diverse groups of marine organisms, characterized by high species richness, diversity of feeding guilds, life styles, and mobility types. Marine annelids are useful indicators of ecosystem responses to changes in environmental conditions. The aim of our study was to assess the influence of natural and anthropogenic factors on functional diversity of polychaete communities in the Gulf of Guinea, a large marine ecosystem (LME) located in West Africa. This area can be considered as a model marine ecosystem affected by various human influences, such as pollution associated with the oil industry. Material was collected in 2012 across the coast of Ghana. Samples were gathered along four transects, each with six sampling stations (25-1000 m depth range). Analyses of functional richness and evenness, based on generalized linear mixed-effect models and hierarchical partitioning, allowed for complex assessments of the interactions between polychaete communities and environmental factors (e.g., sediments, total organic matter, salinity, fluorescence, oxygen, concentration of toxic metals, total hydrocarbons). Overall species richness of polychaetes was outstandingly high, with 253 species recorded. Functional richness decreased along a depth gradient, while functional evenness increased with depth, and was positively correlated with Ba content, which reached the highest values in the upper bathyal. Gravel content was an important factor in shaping functional composition of shallow water communities. High values of functional richness observed in the shallows may be an expression of high stability of this ecosystem, at the same time indicating its high resilience. Elevated concentrations of lead also influenced community structure at a local scale. Our study demonstrated how a complex set of factors operating along a depth gradient can influence the functional composition of communities. These results are crucial for future management of industrial and environmental protection activities in this region.

Two new species of the order Plectida are described from Chatham Rise, New Zealand. Leptolaimus dififtinus sp. nov. is characterised by the short body 319-420 microns long, truncate labial region slightly offset from body contour and bearing conspicuous outer labial papillae, cephalic setae 1.3-1.4 microns long, amphid located 4-9 microns from anterior end, lateral alae originating from middle of buccal cavity length, female without supplements, male with precloacal and postcloacal pairs of subventral setae, nine tubular supplements (alveolar supplements absent), tubular supplements weakly S-shaped with pointed tip, spicules arcuate 24 microns or 1.4 cloacal body diameters long and dorsal gubernacular apophyses. Lavareda iramscotti sp. nov. is characterised by adult body length 3,023-3,121 microns long, eight longitudinal rows of body pores each with short papilla, cephalic setae 4-5 microns long, tail 146-165 microns long, male with spicules 54 microns long, gubernaculum with triangular apophyses, 20 precloacal supplements with bifid distal tips arranged in 9 + 1 + 10 pattern, female with vulva at 55% of body length from anterior and cuticularisation perpendicular to vagina at level of vulva. The present study provides the first record of a Leptolaimus species from the New Zealand region and the first description of a female specimen of the genus Lavareda.

The biological marine system in the Mediterranean Sea off Alexandria, Egypt, was investigated to recognise its biodiversity and the relations among \"ichthyofauna, invertebrates, and benthic\" cover including biota and flora, as well as seabed bathymetry during 2017 using a multi-seasonal surveys by the commercial bottom trawler. Moreover, zooplanktonic community from the water column was also collected to support the picture of the biodiversity in the investigated area. The identified species were 94 fishes, 64 invertebrates, 6 benthic flora, and 304 zooplanktonic species. The ichthyofauna included 5 Chondrichthyes species (5.3% of the fish species), while Osteichthyes fishes were 89 species (94.7%) belonging to 48 families and 72 genera. The most abundant family was Sparidae (13 species). The highest abundance of fishes occurred in the summer (68 fish species 72.34%), while the lowest abundance occurred in the spring (49 species, 52.13%). Regarding the demersal and benthic biota, the most abundant phylum was Mollusca (31 species) and represented by three classes (Bivalvia, Cephalopoda, and Gastropoda). Gastropoda was the most abundant class (18 species), while the lowest Phyla was Chordata (1 species of Ascidians) and Annelida (1 species). The number of lessepsian fish species were 17 (18.1%) of the total number of species caught by the bottom trawl net. In addition, this work provided new records Aulopareia unicolor (F): Gobiidae) for the area for first time and considered the second time in Egypt. The benthic flora was represented by 6 species belonging to three phyla (Tracheophyta, Chlorophyta, and Rhodophyta). Sea grasses were represented by three species (Posidonia oceanica, Cymodocea nodosa, and Halophila stipulacea). The highest abundance of benthic species occurred in the summer (53 species with 75.7%), while the lowest one was in autumn (27 species, 38.6%). Geologically, the fishing ground constituted of hard rocks to very fine silt. The eastern part of the study area includes terrigenous Nile sediment origin, while the western side has biocalcareous sediment with shell fragments richness, coastal limestone ridges origin. The continental shelf, which runs along the study area, is portrayed by a 200-m contour line. In the water column, zooplanktonic community was represented by 304 taxa, belonging to 12 phyla, 6 phyla (Arthropoda, Tintinnida, Chordata \"fish eggs and larvae\", Cnidaria, Foraminifera, and Radiozoa) were dominant. Copepods were the dominant group (71.59%); its annual average abundance was 1271 ind./m3. Its most diversified season was the winter (175 No/m3.) and its average abundance was 1892.9 ind./m3. However, in spring, 118 species were recorded presenting the highest average abundance (2419.4 ind./m3). The lowest diversified season was summer (85 organisms) with density of 1150 ind./m3. The present work offers updated data regarding the marine biodiversity in Egypt, enriches the gaps in the bibliography in the Eastern Mediterranean, and gives preliminary list of species and biodiversity of bottom trawl combined with the interaction with other biosystems and features of fishing ground. These data could be used to monitor evaluate the impact of bottom trawl on the fisheries habitats and changing in ecosystems. Also, it could be used as constructive step to manage or protect such area in combination with other. It is recommended to fulfil the need for more and detailed studies in all areas by different gears to cover the gaps in marine biodiversity data.

Marine fungi, one of the major decomposers of marine environment, is found to produce potential enzymes and novel biomolecules. The present study explored bioprospecting potentials such as antimicrobial, anticancer and enzymatic activities of marine sediment-derived fungi isolated from continental slope of Eastern Arabian Sea. Morphology and ITS sequencing identified the fungus as Penicillium sp. ArCSPf. The fungal strain exhibited amylase, gelatinase, phytase, lipase and pectinase activity. The active fraction obtained from the ethyl acetate extract column fractionation (F2) of fungus showed antibacterial activity against both methicillin-resistant Staphylococcus aureus (MRSA) and Bacillus cereus. Minimum inhibitory concentrations of F2 were 125 μg/mL for MRSA and 62.5 μg/mL for B. cereus. The active fraction showed a significant anticancer activity (IC50 = 22.79 µg/mL) against MCF-7 breast cancer cells. The secondary metabolite (Z)-Octadec-9-enamide (oleamide, m/z 282.27 (M + H+)] was identified in the LC-MS/MS analysis of active fraction F2 in positive ionisation mode. To the best of our knowledge, this is the first report on exploring the bioprospecting potential of a sediment-derived fungus from continental slope of eastern Arabian Sea for the production of therapeutically active compounds.

Marine environments are substantially untapped source for the isolation of bacteria with the capacity to produce various extracellular hydrolytic enzymes, which have important ecological roles and promising biotechnological applications. Hydrolases constitute a class of enzymes widely distributed in nature from bacteria to higher eukaryotes. Marine microbial communities are highly diverse and have evolved during extended evolutionary processes of physiological adaptations under the influence of a variety of ecological conditions and selection pressures. A number of marine hydrolases have been described, including amylases, lipases and proteases, which are being used extensively for biotechnological applications. The present study was carried out to isolate marine bacteria from continental slope sediments of the eastern Arabian Sea and explore their biotechnological potential. Among the 119 isolates screened, producers of amylases (15%), caseinases (40%), cellulases (40%), gelatinases (60%), lipases (26%), ligninases (33%), phytase (11%) and Malachite Green dye degraders (16%) were detected. Phylogenetic analysis based on 16S rRNA gene sequencing showed that predominant marine sediment bacteria possessing more than four enzymatic activities belonged to the phyla Firmicutes and Proteobacteria, was assigned to the genera Bacillus, Planococcus, Staphylococcus, Chryseomicrobium, Exiguobacterium and Halomonas. Biodegradation of the dye Malachite Green using the liquid decolorization assay showed that both the individual cultures (Bacillus vietnamensis, Planococcus maritimus and Bacillus pumilus) and their consortium were able to decolorize more than 70% of dye within 24 h of incubation. This is the first report on diversity and extracellular hydrolytic enzymatic activities and bioremediation properties of bacteria from continental slope sediment of eastern Arabian Sea.

OBJECTIVE: To document biogeographic patterns in the deepwater benthic epifauna and demersal fishes of southern Australia, and determine whether museum records and systematic survey data provide matching results.
METHODS: Southern Australian (32-44oS) continental slope (200-3,000 m deep).
UNASSIGNED: Marine benthic fauna (Arthropoda, Bryozoa, Cnidaria, Echinodermata, Mollusca, Porifera, Sipuncula, and fishes).
METHODS: All available electronic records of fauna from the above taxa and ≥200 m depth off the southern Australian coastline, regardless of organism size, were collated from Australian museums and checked for geographic and taxonomic consistency. These records were then split into 40 geographic segments of roughly equal numbers, with each segment then treated as a sample in multivariate analyses of assemblage composition. Data from a recent (2015) systematic beam trawl survey along five north-south transects in the central Great Australian Bight were also included for comparison.
CONCLUSIONS: The systematic survey data grouped with the associated geographic segments despite differences in sampling technique (single gear compared to multiple gears), with subsequent differences in taxonomic biases, and the use of a 25 mm mesh, which would undersample some smaller organisms present in the museum data. Thus, the museum data and the survey data provided the same results for the central Great Australian Bight at the level of the whole assemblage. The main biogeographic break occurred off southeastern Tasmania, with a second substantial break occurring at around the border between New South Wales and Victoria. This indicates the potential for unused museum data to describe biogeographic patterns over regional spatial scales, especially in the deep sea where the expense of collecting new data is relatively high.