Effect of different water temperatures on the hatching time and survival rates of the freshwater crayfish Astacus leptodactylus (Esch., 1823) Eggs

Abstract

In this study, freshwater crayfish (Astacus leptodactylus, Esch, 1823) eggs were incubated starting seven weeks after spawning, at three different temperatures (11.8 °C, 16±1°C and 20±l°C) and the results were compared with respect to hatching time and survival rate. The eggs hatched between days 116 and 125, 88 and 97, and 69 and 74, at 11.8 °C, 16 ±1 °C, and 20 ±1 °C, respectively. The survival rates at these temperatures were 22.4%, 46.9% and 32.5%. In conclusion, it was found that A. leptodactylus eggs could hatch 1.5 months earlier than under natural conditions by increasing water temperature, starting in March, up to 20 °C, but the optimum temperature for maximum hatching rate was found to be around 16°C.