The use of underwater camera in studies of vertical distribution and swimming behaviour of a sergestid shrimp, Sergia lucens

Abstract

The vertical distribution and swimming behaviour of Sergia lucens were investigated by means of underwater photography. During the day the species was abundant from 3 to 7 m above the bottom on the upper continental slope at depths from 210 to 360 m. No shrimp were observed closer than 0.5 m above the bottom. The maximum concentration observed was 6.1 individuals m⁻³. It is speculated that in many areas on the continental slopes and rises, the density of zooplankton and micronekton is much higher near the bottom in the day than in the overlying midwater, and that this may provide a concentrated pelagic food for predators close to the seafloor.