Development of the activities of oxidative, glycolytic and muscle enzymes during early larval life in three families of freshwater fish

Abstract

The development of the activities of oxidative (COX, CS), glycolytic (PFK, PK, LDH) and muscle enzymes (CK, MK, Pase) was studied in representatives of the families Coregonidae, Salmonidae and Cyprinidae, from hatching to an age of approximately 100 days. In addition, the activities of two enzymes of amino acid metabolism (GOT, GPT) were followed in rainbow trout and in roach.Water content of fresh body weight and protein content of dry body weight decrease during the early larval period. Specific activities of the two oxidative enzymes decline, whereas those of glycolytic and muscle enzymes increase in all species.A family‐specific event is the enormous increase in glycolytic and muscle enzymes from very low values in the early larva to very high levels in adult Coregonus sp. In rainbow trout, CS activity begins with a low‐level period lasting throughout the yolk‐sac period, whereas in the other species CS activity is high immediately after hatching.Acclimation to either 15 or 20° C has no effect on the mass‐specific activities of PFK, M K, CK and Pase in roach and chub, but the former three enzymes appear to be strongly dependent on rearing conditions during the early larval period, whereas Pase is not.