The Significance of Squid, Whale and Other Remains From the Stomachs of Bottom-Living Deep-Sea Fish

Abstract

Twenty-four out of 240 fishes caught by bottom lines at 366–3333 m had something in their stomachs. Stomach contents included parts of cephalopods, fish, cetaceans and bottom-living invertebrates, thin rubber sheet and terrestrial mammal bones. The material provides evidence that four species of cephalopod are at least partially demersal and suggests a means by which the tapeworm Phyllobothrium could pass from its secondary to its primary host.During the five biological cruises of R.R.S. ‘Discovery’ between 1967 and 1971 a total of 31 bottom lines with 1483 hooks were fished in depths of water between 366 and 3333 m. The stomachs of the 240 fish caught were examined and 216 (90%) proved to be empty. The high incidence of empty stomachs is thought to be due to frequent loss of food during the ascent from great depths and accounts for our poor knowledge of the feeding habits of demersal fish living at depths exceeding 400 m.The present collection of food from 25 stomachs (24 from ‘Discovery’ collections and one from a fish caught by Mr G. R. Forster from R. V. ‘Sarsia’) of fish belonging to 11 species (Table 1) probably gives little indication of the usual diet of the fish concerned, but its nature prompts some useful speculation and the rarity of such observations justifies placing them on record (Bigelow & Schroeder, 1948; Marshall, 1954).All the fish were caught on lines which lay on the bottom for several hours and it is our firm belief that they were hooked while on or very near the bottom.