Abstract:Exopalaemon carinicauda is one of the special economic shrimp in China, which has become an important object of pond single breeding and mixed breeding in recent years. The ridgetail white prawn has good breeding prospects, however, due to its small size and relatively small spawn, it currently mainly relies on natural seedlings, catching natural seedlings or placing broodstock to propagate their own seed, which severely restricts the development of large-scale artificial aquaculture. To achieve large-scale artificial breeding of white shrimp, we must break through the difficulty of full artificial breeding, and the bait is the nutritional basis to ensure the normal growth and development of seedlings. Biological diet generally refers to various aquatic plants, animals and microorganisms that can be artificially cultivated and suitable for aquatic animals to eat. Compared with traditional feed, biological food has many advantages, such as easy to cultivate, fast reproduction, rich nutrition, and strong palatability, and can effectively enhance the disease resistance ability of breeding objects. At present, the commonly used biological food includes Chaetoceros muelleri, chlorella, microcytococcus, cyanobacteria, rotifer, Artemia, cladocera, copepod and amphipoda. In this study, we analyzed the survival rate, larval stage index, and digestive enzymes of Exopalaemon carinicauda larvae (Z1~P) fed live food, including group A (feeding only on Artemia nauplii), group B (Chaetoceros muelleri and A. nauplii mixed feeding), group C (Brachionus plicatilis and A. nauplii mixed feeding), and group D (C. muelleri, B. plicatilis, and A. nauplii mixed feeding). The results showed that group A had the highest metamorphic rate, and all individuals metamorphosed into larvae within 14 days, while the other three groups took 15 days. The survival rates of larvae metamorphosed into larval shrimp were 84.33%, 84.67%, and 83.00% for groups A, B, and C, respectively, and the differences among the three groups were not significant (P>0.05). A large number of larvae during the Z5~P stage died in group D, and the survival rate was only 35.67%. Moreover, the activities of pepsin (1.94 U/mg prot), lipase (2.35 U/mg prot) and α-amylase (0.13 U/mg prot) were the highest in group A, while the activities of pepsin (0.08 U/mg prot), lipase (0.91 U/mg prot) and α-amylase (0.08 U/mg prot) were the lowest in group D. The activities of α-amylase in groups B and C were 0.12. The activities of lipase (1.78 U/mg prot) and respectively (0.39 U/mg prot) in group C were 0.35 U/mg prot and 0.04 U/mg prot higher than those in group B. This study suggests that feeding E. carinicauda larvae with A. nauplii (3~5 ind./mL) is expected to increase the survival rate of larvae and accelerate metamorphosis during the nursery phases and supplementation with C. muelleri can alleviate the rate of deterioration in aquaculture water.
