Somatic growth of juvenile freshwater crayfish Cherax quadricarinatus, by ecdysone added to different diets.

CHAULET, A.; LÓPEZ-GRECO; L.S. AND E.M. RODRIGUEZ.

Topicos Especiais em Biologia Aquatica e Aquicultura II

Sociedade Brasileira de Aquicultura e Biologia Aquatica

Lugar: Jaboticabal; Año: 2008; p. 305 - 313

Assays combining two types of diets (commercial fish meal and krill meal) with or without the addition of á-ecdysone, were run on both early and advanced juveniles of the red claw crayfish Cherax quadricarinatus. Juveniles were weighed every 2 wk during 4 months, also recording molting and mortality. At the end of the assays, some significant differences among experimental groups (P<0.05) were noted for early juveniles, but not for the advanced ones. Such differences consisted in both a higher weight gain and specific growth rate by effect of the krill meal, compared to the other diet. Besides, addition of ecdysone to the krill meal was able to increase even more the above mentioned variables. Several hormones and other growth factors presented in krill meal would be responsible for the increased growth observed in C. quadricarinatus juveniles. Since ecdysone produced neither a higher frequency nor percentage of molting, its effect on early juvenile growing seems to be related to an anabolic effect of this hormone during the intermolt period. Key words:  cherax, crayfish, diet, ecdysone, growth, krill meal