Squid as feed for salmonids

Abstract

The populations of squid and cuttlefish in the oceans are an enormous source of protein. Only 500 000 metric tons, which may be only 0.5% of the potential catch, is harvested annually. Not only offal from processing of squid but also species and catches not destined for human consumption are potential sources of protein in aquaculture. Flying squid ( Todarodes sagittatus Lamarck), stored frozen, was tested in moist diets for rainbow trout ( Salmo gairdneri Richardson) and salmon ( Salmo salar L.). In the test diets, the three squid parts — mantles, whole bodies, and tentacles, heads and guts — each replaced argentine ( Argentina silus Ascanius) which was used in the control diet. On a wet weight basis the diets contained about 46% squid. The diets were approximately isoenergetic and had the same protein: fat ratio. The presence of squid in the diet resulted in greater increases in weight and length, a higher condition factor, no change in carcass percentage and higher dry matter and fat contents in both rainbow trout and salmon than with the control diet. There were no significant differences in these production traits between the fish that received the three different squid parts.