The exploration of artificial incubation of Cherax quadricarinatus eggs.

ABSTRACT

The redclaw crayfish, Cherax quadricarinatus, is an economically valuable freshwater crayfish. However, some production obstacles, such as a low egg hatching rate and asynchronous hatching, are hindering its development in the aquaculture industry. Artificial incubation of eggs may solve these problems. This study explored the technology of artificial incubation of redclaw crayfish eggs. The following results were obtained 1) 75% alcohol as a disinfectant for 60 s had a preferable antibacterial effect and promoted the hatching rate; 2) densities of 300 and 600 eggs/incubator resulted in significantly higher hatching and survival rates than a density of 900 eggs/incubator; 3) at a density of 600 eggs/incubator, the optimum number of net pieces for attachment of freshly hatched juveniles was 20 per incubator; 4) with a density of 600 eggs/incubator and 20 net pieces/incubator, the hatching rate was 82.05% ± 4.09%, the survival rate was 55.12% ± 7.51%, and a total of 129,200 SPF (specific pathogen-free) seedlings were cultivated. This artificial incubation system was maintained at close to an aseptic state, with an absence of white spot virus, iridovirus, Vibrio and ciliates; this was true for all water sources used and for incubation of both eggs and juvenile crayfish. In conclusion, if we implement reasonable methods of disinfection, SPF detection and pathogen isolation and utilize optimal egg densities and incubation systems, large-scale production of SPF seedlings of Cherax quadricarinatus is possible.