Effects of dead egg removal frequency on stage 2 juvenile productionin artificial incubation of Austropotamobius pallipes Lereboullet.

摘要

In artificial incubation (AI) of astacid species, which have a long embryonic development, eggs have to remain during long periods without maternal care and it is recommended to remove the dead ones. With the aim to test the effect on final stage 2 juvenile production of different removal frequencies, four treatments were tested: removal every 4 days, every 7 days, every 10 days and no removal. Using an egg density of 2.2 eggs/cm super(2) , stage 2 juvenile production rate was significantly better (70.3%) with removal every four days than with less frequent removals. However there were not detected statistical differences between the control (no egg removal) and the other treatments. The relatively low incubation density (2.2 eggs/cm super(2) ) could partially explain the general good results achieved, even when dead eggs were not removed.