不同生物饵料组合对脊尾白虾幼体变态发育的影响

Effects of live food combinations on the metamorphosis and larval development of Exopalaemon carinicauda

关键词:  脊尾白虾  生物饵料  幼体发育指数  消化酶

Key words:  Exopalaemon carinicauda  Live food  Larval stage index  Digestive enzymes

摘要:

本研究以脊尾白虾(Exopalaemon carinicauda)幼体为研究对象，研究了牟氏角毛藻(Chaeroeeros moelleri)、褶皱臂尾轮虫(Brachionus plicatilis)和卤虫(Artemia salina)无节幼体搭配投喂对脊尾白虾幼体的存活率(SR)、变态发育和消化酶的影响。结果显示，单一卤虫组的幼体变态发育速度最快，14 d内全部变态为仔虾，其他3组则需要15 d；单一卤虫组、牟氏角毛藻+卤虫组和轮虫+卤虫组的幼体变态为仔虾时的SR分别为84.33%、84.67%和83.00%，各组间差异不显著(P>0.05)；投喂牟氏角毛藻+轮虫+卤虫混合饵料组的幼体在Z5~P阶段大量死亡，变态为仔虾时的SR为35.67%。单一卤虫组投喂的脊尾白虾幼体的胃蛋白酶(1.94 U/mg prot)、脂肪酶(2.35 U/mg prot)和α-淀粉酶(0.13 U/mg prot)活力在4个组中最高，牟氏角毛藻+轮虫+卤虫组的胃蛋白酶(0.08 U/mg prot)、脂肪酶(0.91 U/mg prot)和α-淀粉酶(0.08 U/mg prot)活力在4个组中最低；牟氏角毛藻+卤虫组和轮虫+卤虫组的α-淀粉酶活力均为0.12 U/mg prot，而轮虫+卤虫组幼体的脂肪酶(1.78 U/mg prot)和胃蛋白酶(0.39 U/mg prot)比牟氏角毛藻+卤虫组分别高0.35和0.04 U/mg prot。研究表明，在脊尾白虾育苗过程中，投喂卤虫无节幼体(3~5 ind./mL)，能提高幼体SR和加快变态发育速度，同时，在养殖过程中加入一定的牟氏角毛藻可减缓养殖水体恶化的速度。

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.