IS METAMORPHOSIS A CRITICAL INTERVAL IN THE EARLY-LIFE OF MARINE FISHES

Small volumes of food in 'stomach', large proportions of empty 'stomachs' and small maximum sizes of prey during metamorphosis of cod, Gadus morhua, all point to an energy crisis during this developmental interval. The small size of the developing stomach of the 10-14 mm long cod may be partly responsible for the above mentioned difficulties during metamorphosis. A hypothesis based on Hjort's 'critical stage theory' is proposed, adding another critical interval at metamorphosis. Based on the presented data on cod and reports on other species in the literature, the new critical interval is discussed for larvae of marine fish species in general.