Investigation on reproductive potential in male narrow-clawed crayfish Astacus leptodactylus Esch

摘要

Two experiments are carried out in two contiguous years to investigate the reproductive possibilities in male narrow-clawed crayfish Astacus leptodactylus Esch. and their ability for repeated participation in reproductive process. There were used cultivated crayfish witch are put on in 50 1 aquariums at a sex ratio of male:female lake a 1:1,1:2,1:3,1:4,1:5,1:6,1:7 and 1:8 in two or four repetition. The following features were studied: period of mass mating, rate frequency of male crayfish participations in the reproductive process, interval between two contiguous matings and the time from mating to spawning (egg laying). Mating started when water temperature was decreased to 8-12 degrees C. It was determined that one male crayfish can mate 8 females. There was a high fertilizing activity in male crayfish. The same ones can copulate with 2 or more females during the period of 1 to 3 days. Mass egg laying was carried out in the same day of mating or 1 to 2 days later..