The effect of different cold period during maternal incubation on incubation efficiency and hatching term in Austropotamobius pallipes

Abstract

This study tested the effect on the incubation efficiency (E in %) and hatching term during maternal incubation of Austropotamobius pallipes of five different cold periods (duration: 45, 60, 75, 90 and 105 days) under controlled conditions and one group maintained under ambient Irish water temperatures. The six different durations of cold period, used in this study, caused six different terms of hatching from 16 March to 29 June. When compared to the group held under ambient Irish conditions with fluctuating water temperatures during the incubation period (E = 29.9 ± 4.5%), higher incubation efficiency was found in all groups under the controlled conditions (E = 73.1 ± 4.7% − 41.3 ± 2.7%). In groups under controlled conditions, a positive effect of shortened cold period on incubation efficiency was found, with the highest efficiency (E = 73.1 ± 4.7% − 68.8 ± 5.2%) found after the shortest cold period, while the longest cold period led to the lowest efficiency (E = 41.3 ± 2.7%).

Keywords

• white-clawed crayfish
• egg
• temperature
• hatching
• survival rate