Gastric evacuation rate in mackerel (Scomber scombrus L.)

Abstract

About 1500 mackerel, 25-45 cm in Length, were kept in a net for l0 days. In two experiments the fish were £ed frozen euphausiids -ad. libiturn, and the wet weight of the stomach content determined every second hour for 20-30 hours. The l' stomachs were then almost empty. Independent of fish size, the rate of digestion was related to the water temperature (14.5 - 17.0~~: )f (T)= 0.005 Oexp (0.2-T). The niaximum l stomach capacity (wet weight, grams) was a function of fish l size (total length, cm): w = 0.0087eL 2,21 i