Diversity and community structure of pelagic fishes to 5000 m depth in the Sargasso Sea

摘要: The diversity, abundance and distribution of pelagic fishes from 0-5000 m in the Sargasso Sea, northwestern Atlantic Ocean, were investigated, with primary focus on between 1000-5000 m. A large-volume, fine-mesh (335-μm), discrete-depth sampling system was used to sample latter strata 1000-m intervals. Species composition total biomass collected these compared samples taken 0-1000 using a smaller midwater trawl. Samples association Census Marine Zooplankton at-sea DNA-sequencing effort, allowing determination genetic barcodes taxa for which species descriptions do not currently exist (e.g., many male ceratioid anglerfishes). 3965 fish specimens collected, representing minimally 127 (84 genera), 42 families. bristlemouth, Cyclothone braueri, dominated catches both above (47%) below (41%) 1000 Myctophidae Stomiidae most species-rich taxa, while deep-sea anglerfish suborder Ceratioidei diverse bathypelagic taxon. Thirty sequenced data submitted GenBank. New Ocean Biogeographic Information System location records Saragasso Sea logged 84 species. Hydrographic revealed separation region into three physical regimes within top (northern, transition, southern), sub-1000 stratum fairly homogeneous. Though richness, abundance, diversity highest southern Sargasso, indices whole water column (0-5000 m) significantly different regions. Below m, 1000-2000 held assemblage across entire transect, but high exhibited 3000 at two four stations. Ordination discriminated 13 assemblages, related depth far more than region. Geometric class analysis profound differences relative abundances meso- zones former demonstrating much higher percentage common This finding tracks hydrographic patterns observed: increased stability zone favors numbers rare mesopelagic zone, where complexity