Effect of Prey Distribution and Density on the Searching and Feeding Behaviour of Larval Anchovy Engraulis mordax Girard

Abstract

Laboratory estimates of the minimum concentration of food required for survival of marine fish larvae usually are much higher than the average concentrations of food in the sea (O’Connell and Raymond, 1970; Hunter, 1972). A common explanation for the fact that laboratory food requirements exceed natural food densities is that larvae are able to find and remain in patches of food in the sea which are considerably above the average food density estimated from plankton net catches. This explanation is supported in part by Ivlev (1961) who demonstrated with carp fry that an increase in the degree of aggregation of prey had the same effect on food consumed as an increase in the overall density of food material. A patchy distribution of larval food occurs under natural conditions. Thus, the effect of prey distribution on feeding behaviour of larval fish and the scale of “patchiness” of food items in the sea must be known to estimate the impact of food distribution on the feeding and searching behaviour of larval anchovy. This paper described some aspects of the effect of prey distribution and density on the feeding and searching behaviour of larval anchovy Engraulis mordax