Food and feeding of Loligo vulgaris reynaudii from St Francis Bay, South Africa

Abstract

Change of colour, consistency and pH in contents of the caecum and the stomach of laboratory-maintained long-finned squid Loligo vulgaris reynaudii were determined. There was relatively little variability in any of these parameters of the specimens investigated. Colour and consistency of food or emulsion were used as a basis of analysis of stomach-caecum contents of wild squid. Most squid fed late during the night and/or during the early morning, and the frequency of caecum colour categories did not change much between trawls. Wild squid preyed upon different organisms according to their size. Squid of 69–125 mm dorsal mantle length fed mainly on euphausiids (95% by frequency of occurrence, 87,5% by mass) and those of 126–240 mm mainly on fish (78 and 74,3% respectively) with Bregmaceros ?macclellandii and hake as important components. Unidentified fish in the stomachs (i.e. those from which no otoliths were available) probably also belonged to these two species.