Feeding habits of the deep-sea fish, Scopelogadus beanii (Pisces: Melamphaide), in the western North Atlantic

Abstract

Stomach contents were examined from 106 specimens (37–113 mm SL) of the melamphaid Scopelogadus beanii collected from the slope waters of the western North Atlantic Ocean by bottom and midwater trawls. Seventy-five stomachs (70.8%) contained food. Gelatinous zooplankton (mainly salps) and associated obligate and facultative symbiotic hyperiid amphipods of the genera Vibilia, Parathemisto, and Phronima were the predominant food items in the stomachs of S. beanii, although calanoid copepods (especially Paraeuchaeta norvegica) were of similar importance in individuals from offshore midwater trawls. Other pelagic prey items included halocyprid ostracods, euphausiids and fishes. Representatives from three benthic groups (gammaridean amphipods, polychaetes and pelecypods) were recovered from stomachs of specimens from bottom trawls. The only significant pattern observed in diel feeding periodicity was a decrease in the percentage of stomachs containing food between 1201 and 1800 h as compared to the percentage of stomachs containing food between 1201 and 2400 h. This observation might be an artifact, however, because no differences in degree of prey digestion were observed. Limited seasonal data from bottom-trawled collections indicate that consumption of amphipods was highest in spring, whereas that of gelatinous plankton was highest in summer and autumn. There were no apparent ontogenetic shifts in diet composition. Differences in prey importance between bottom and pelagic trawl-captured individuals may be due to vertical ranges and abundance of prey taxa and the presence of S. beanii near the bottom in continental slope waters.