The effect of temperature on the incubation time of freshwater crayfish, Astacus leptodactylus

IV ABSTRACT Master Thesis THE EFFECT OF WATER TEMPERATURE ON THE INCUBATION TIME OF FRESHWATER CRAYFISH, (ASTACUS LEPTODACTYLUS ssp.) Ibrahim TÜRKGÜLÜ Fırat University Graduate School of Natural and Applied Sciences Department of Fish Production and Breeding 2000, Page : 30 The effect of water temperature on the incubation time of freshwater crayfish, (Astacus leptodactylus ssp.) was investigated. Egg-bearing females were exposed to high temperatures in the laboratory in the present study. In addition,at the end of the incubation time, eggs were removed from the females which were kept in ponds, and were placed into the artificial incubators. The results showed that the incubation time of the eggs of A. leptodactylus ssp. which were exposed to high temperatures can be reduced six weeks (first stocking, 19.02.1999) or three weeks (second stocking, 10.03.1999) in comparison with the control. The best water temperature in the first stocking was 16 °C and 22 °C for the second stocking. It was also found that the artificial incubators used for the present study were very efficient. 93-99 percent of the eggs placed into the incubators hatched out. In conclusion, the present study show that it is possible to carry out the reproduction of A. leptodactylus ssp. in Cip Reproduction Unit's conditions, and it is also possible to obtain robust juveniles under the control in this habitat in order to support natural populations and to establish new populations of A. leptodactylus ssp. Key Words: Crayfish, Astacus leptodactylus ssp., temperature, incubation time