Deposit feeding by some deep-sea megabenthos from the Venezuela Basin. selective or non-selective

Publisher Website
Google Scholar
Abstract
Food sources and feeding selectivity of numerically dominant asteroids and holothurians collected with trawls from the Venezuela Basin, Caribbean Sea, were investigated by means of gut analysis. Particle-size distributions of gut contents of Thoracaster cylindratus, Styracaster horridus, Psychropotes semperiana and Pseudostichopus atlanticus and of sediments were compared from 3 different sedimentary provinces in the Venezuela Basin (3410-5062 m depth). Megabenthic echinoderms (megabenthos) from the 2 shallower provinces had gut contents with particle-size distributions almost identical to that of the top 5 mm of sediment and conspicuously coarser than sediment below 5 mm depth. Gut contents of echinoderms from the deepest province had a higher precent of coarse and medium sand-size foraminiferan tests than that of surrounding sediment. Microscopic examination of the coarse fractions revealed intact pelagic foraminiferan tests in the guts of megabenthos collected from 5000 m depth; pelagic foraminiferan tests from surrounding surface sediments were fragmented and eroded. The possibility of recently settled fecal pellets from the pelagic realm as a food source is suggested. These data suggest that some bulk deposit feeders skim the surface of the sea bottom feeding on the uppermost layer of sediment; thus, they selectively ingest the more nutritive, uppermost layer of sediment in the deep sea without modifying feeding behavior per se.
Keywords

This publication has 1 reference indexed in Scilit: