ABSTRACT

A suitable temperature regime in artificial incubation of crayfish eggs is crucial for successful application in aquaculture production and conservation projects. We studied the effect of different extended cold periods (CP: 10, 24 and 38 days at 7.5 ± 0.5°C) during artificial incubation on embryonic development, incubation efficiency and subsequent juvenile crayfish performance in noble crayfish. Best results were obtained at 38-day CP with stage II survival rate of 60.4 ± 7.4% and stage II wet weight of 38.4 ± 1.9 mg. This regime synchronized embryonic development and equally reduced hatching and moulting period to 7 days with no overlap between both. Survival was high in a subsequent 100-day rearing experiment (10-day CP: 85.0 ± 9.2%; 24-day CP: 90.0 ± 4.1%; 38-day CP: 92.5 ± 2.9%) and juvenile crayfish from 38-day CP grew faster, but these results were not significant. Staggered response of embryonic development to temperature rise and improved juvenile fitness at longer CP illustrate that dormancy of noble crayfish eggs represents a form of true diapause that is regulated solely by temperature and can be accelerated beyond a threshold only at the expense of higher mortality and reduced juvenile fitness.

抽象的

在小龙虾卵的人工孵化中，合适的温度范围对于在水产养殖生产和保护项目中的成功应用至关重要。我们研究了人工孵化过程中不同的延长的寒冷时期（CP：7.5、0.5°C下的10、24和38天）对贵族小龙虾胚胎发育，孵化效率以及随后的小龙虾性能的影响。在CP第38天获得最佳结果，II期生存率为60.4±7.4％，II期湿重为38.4±1.9 mg。该方案使胚胎发育同步，并且将孵化和换羽期平均减少到7天，而两者之间没有重叠。在随后的100天饲养实验中存活率很高（10天CP：85.0±9.2％; 24天CP：90.0±4.1％; 38天CP：92.5±2.9％）和38天CP的小龙虾增长更快，但是这些结果并不显着。较长的CP时，胚胎发育对温度升高的反应错综复杂，并提高了幼体的适应性，这说明小龙虾卵的休眠代表了真正的滞育，仅由温度调节，只有在增加死亡率和降低死亡率的情况下，才可以加速超过阈值。青少年健身。