The fat/water relationship in the mackerel Scomber scombrus L., pilchard, Sardina pilchardus (Walbaum) and sprat, Sprattus sprattus L., and the seasonal variation in fat content by size and maturity.

Abstract

Mackerel, pilchard and sprat have the ability to store fat in their body tissues. During the spring and summer, when their main source of food, zooplankton, is abundant, fat reserves are accumulated. These reserves are utilized in the autumn and winter when zooplankton are scarce. Consequently, wide variations in fat content occur throughout a single year of life of these species. This report describes the relationship that exists between fat and water in these species and describes how the fat content varies with size, maturity stage and season.