As with lobster, the meat perishes rapidly after death. Softshell crayfish are those that have just completed the molting process. Crayfish meat is sweet similar to lobster meat but a bit more tender and not quite as rich. Limited amounts are farmed in Europe, Egypt and Spain. Fishermen in the Midwest trap the species in lakes. In California, fishermen trap coolwater crayfish in rivers that feed the Sacramento Delta. In China, crayfish are cultivated in ponds with other fish and sea life. Crayfish are also farmed and harvested wild in other southern states and in the Pacific Northwest. Approximately 90% of the United States farmed and wild crayfish production comes from Louisiana, where crayfish are caught in the wild and farmed as a dual crop with rice. Second is the white-river crayfish from northern Louisiana. species is red swamp crayfish, found in southern Louisiana. 400+ species are found worldwide, 250 of which are in North America, found in rivers, lakes, swamps, canals, wetlands, irrigation ditches, and even in some backyards.
Additionally, ECR and α-AMY expression could reflect the growth rate of the juveniles, but not their survival.Crayfish are freshwater crustaceans that are basically miniature lobsters, ranging in size from 3.5 to 7 inches (including their outstretched claws). Thus, these conditions possibly improved digestion and absorption and also promoted molting in the juveniles. Overall, red claw crayfish juveniles showed higher survival rates, greater antioxidant and immune activities, and lower monoamine contents under red light, 6 L:18D or 0 L:24D conditions. However, interfering with ECR expression reduced juvenile growth rate, while ECR or α-AMY gene overexpression enhanced their growth rate. (4) EcR or α-AMY gene interference or overexpression had no significant effect on juvenile crayfish survival. (3) The 6 L:18D, 12 L:12D, and 0 L:24D groups showed significantly higher α-AMY expression levels, while EcR expression was significantly higher in the 6 L:18D and 0 L:24D groups. Additionally, the SOD and ACP activities corresponding to the 6 L:18D and 0 L:24D group were significantly higher, while its MDA and DA concentrations were significantly lower. (2) The 0 L:24D and 6 L:18D photoperiod groups showed significantly higher survival rates than the 24 L:0D group. The blue light group showed the highest α-AMY expression level, while the EcR expression levels corresponding to the yellow and red light groups were significantly higher. The yellow light group presented significantly higher SOD activity, and lower DA concentration. Further, the red light group showed significantly higher superoxide dismutase, acid phosphatase, and alkaline phosphatase activities, but significantly lower malondialdehyde, serotonin, noradrenaline, and dopamine concentrations. (1) The red light group showed the highest survival rate, while the blue light group showed the fastest growth rate. Experiments involving five light color groups (red, green, blue, yellow, and white light), five photoperiod groups (0 L:24D, 6 L:18D, 12 L:12D, 18 L:6D, and 24 L:0D), besides, we also studied the effects of interference and overexpression of these genes on growth, survival, and their expression. 738740 ISSN: 0044-8486 Subject: Cherax quadricarinatus, absorption, acid phosphatase, alkaline phosphatase, antioxidant activity, antioxidants, aquaculture, blue light, color, crayfish, digestion, dopamine, gene overexpression, genes, juveniles, malondialdehyde, norepinephrine, red light, serotonin, superoxide dismutase, survival rate, white light Abstract: To determine the optimal light color and photoperiod conditions for red claw crayfish juveniles, we studied the effects of these factors on their survival, growth, monoamine content, antioxidant capacity, nonspecific immune index, and the expression of EcR and α-AMY genes.
Effects of light color, photoperiod, and growth-related gene interference or overexpression on the survival, growth, or physiological and biochemical indices of red claw crayfish juveniles Author: Shun Cheng, Jian-bo Zheng, Yong-yi Jia, Mei-li Chi, Wen-ping Jiang, Shi-li Liu, Fei Li, Yi-nuo Liu, Zhi-min Gu, Dan-li Wang Source: Aquaculture 2023 v.562 pp.
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