Effect of different substrates on survival and growth of juveniles of the freshwater narrow-clawed crayfish Astacus leptodactylus Eschscholtz, 1823 (Decapoda, Astacidae)

Abstract

Substrate is a key factor for successful crayfish culture, and it can be used to increase the survival rate. The effects of substrate on the survival and growth ofAstacus leptodactylusEschscholtz, 1823 were evaluated in flow-through compartments, divided into three sections and with two different substrates, over a period of 90 days. The three treatments used in the study were: artificial ropes, small stones, and a control group that received no substrate. The survival rate was highest in the small-stones treatment group (77.3%) and was lowest in the without-substrate treatment group (41.3%), while the artificial-ropes group showed an intermediate value (65.3%). Total yield was lower in the control group, 22.46% (25.0 g) as compared to the small-stones treatment group, with 42.3% (51.3 g) and the artificial-ropes treatment with 35.51% (55.8 g). In addition, cheliped injuries were found in higher proportion in the group without cover, and the artificial ropes yielded better results compared to the small-stones and no-substrate group in regard of the growth-increase rate.