Growth of redclaw crayfish Cherax quadricarinatus (Von Martens 1868) (Decapoda: Parastacidae) juveniles fed isoproteic diets with partial or total substitution of fish meal by soya bean meal:: preliminary study

Growth of juvenile redclaw Cherax quadricarinatus fed 400 g kg(-1) crude protein isoproteic diets substituting fish meal with soya bean meal at various levels (250, 500, 750 and 1000 g kg(-1)) was evaluated under laboratory conditions. Juvenile crayfish were reared individually in 1-L plastic containers for 56 days. Total survival was recorded for all treatments at the end of the experiment. There were no significant differences (P>0.05) for the specific growth rate among the treatments, although the animals fed with the control diet (100% fish meal) obtained the highest mean daily weight gain (0.055 g day(-1) ), individual final weight (4.12 g), molts per individual (0.04 molts day(-1) ) and molting frequency (23.57 days) values at the end of the experiment. Dietary inclusion of soya bean meal at the tested levels hampered the C. quadricarinatus juvenile growth.