Abstract

The effect of diet on the growth and survival in captivity of the octopus Enteroctopus megalocyathus Gould, 1852 was researched to establish culture potential. This is one of two commercially important octopus species that inhabit the Chilean coast. A positive energy budget, averaging 678 J day -1 g of dry weight (dw), was recorded in specimens maintained in tanks and fed ad libitum on a diet of three species of crustacean decapods. On the other hand, the energy budget of octopus specimens fed on the mussel Mytilus chilensis (Hupé) was negative, averaging -250.90 J day -1 g dw -1. Ingestion rates varied between diets (t=46.45; d.f.=18; P<0.001), but no variations were recorded in energy loss resulting from metabolism (t=0.67; d.f.=16; P>0.05) or ammonia excretion (t=1.39; d.f.=16; P>0.05). An average instantaneous growth rate (IGR) of between 1.96% and 0.49% was recorded in specimens fed on crustaceans, depending on the size of the octopus and the period of time. The IGR in specimens fed on mussels was -0.32±0.05. The IGR of specimens fed on crustaceans and maintained in suspended systems was 1.36±0.9%. The mean mortality with crustacean and mussel diets was 11.07±5.5% and 74±1% respectively. The results indicate that E. megalocyathus can survive and grow in captivity, both in tanks and in suspended systems, when fed on a diet of crustaceans. © 2006 Blackwell Publishing Ltd.