凡纳滨对虾亲虾繁殖期间适宜投喂频率的研究

Optimum feeding frequency for Litopenaeus vannamei during the breeding period

中文关键词: 投喂频率  生长  繁殖性能  消化酶活力  凡纳滨对虾亲虾

英文关键词: Feeding frequency  Growth  Reproductive performance  Digestive enzyme activity  Broodstock Litopenaeus vannamei

中文摘要:

      在饱食投喂条件下，选用鲜活饵料沙蚕(Nereis succinea)对凡纳滨对虾(Litopenaeus vannamei)亲虾进行营养强化培育60 d，通过比较不同的投喂频率2次/d(F2组)、3次/d(F3组)、4次/d(F4组)对亲虾摄食、生长、繁殖性能、虾体组成和肝胰腺的消化酶活力的影响，旨在探究亲虾繁殖期间营养强化的最适投喂频率。结果显示，随着投喂频率的增加，亲虾的日摄食量逐渐增大，F2组显著低于F4组(P<0.05)，但与F3组差异不显著(P>0.05)；亲虾的增重率和体长增长率呈先升高后降低的趋势，但无显著性差异(P>0.05)。不同的投喂频率对各组亲虾的单次产卵量、相对产卵量、无节幼体I期个体数、无节幼体孵化率、蚤状幼体I期个体数、无节幼体变态率、性腺指数、初产时间和产卵间期均无显著影响(P>0.05)。亲虾全虾主要体组成分水分、粗蛋白、粗脂肪、灰分含量也不受投喂频率增加的影响(P>0.05)；F2组的胰蛋白酶和脂肪酶活力显著低于F3、F4组(P<0.05)，而不同实验组的胃蛋白酶和淀粉酶活力无显著性差异(P>0.05)。结合本研究的结果和生产实际情况，建议在饱食投喂条件下，凡纳滨对虾亲虾繁殖期间营养强化的适宜投喂频率为2次/d。

英文摘要:

      A study was conducted to investigate the effect of feeding frequency on growth, reproductive performance, body composition and digestive enzyme of broodstock Litopenaeus vannamei. Experimental broodstock were fed with Nereis succinea for 60 days. Before the start of the experiment, the unilateral eye socket of each broodstock was placed on the eye as an individual marker and the initial body length and weight of each female were determined. The average initial body weight was 41.78 g and the average initial body length was 15.80 cm. The broodstock were randomly divided into three round pools, each with 40 shrimps. Three groups of broodstock were fed to satiation in two times per day, three times per day and four times per day, which were represented by F2, F3 and F4 groups, respectively. Results showed that the feeding amount of broodstock increased gradually with the increase of feeding frequency, and the F2 group was significantly lower than that in group F4 (P<0.05), but there was no significant difference between the F3 group and the F2 group (P>0.05). The weight gain and body length growth of broodstock increased first and then decreased with the increase of feeding frequency, but there was no significant differences among treatments (P>0.05). Reproductive performances of Litopenaeus vannameimei were not affected by different feeding frequency in current study (P>0.05). There were no significant differences in single fecundity, relative fecundity, the number of nauplius stage I, hatching rate, the number of zoea stage metamorphosis rate (N1-Z1), gonadosomatic index(GSI),first spawning time and the spawning intervals (P>0.05). The body composition of Litopenaeus vannamei including moisure, crude protein, crude Lipid and ash were not affected by feeding frequency (P>0.05). The results showed that the activity of trypsin and lipase of hepatopancreas in the F2 group was significantly lower than that in the F3 and F4 groups (P<0.05), but there was no significant differences among the activity of pepsin and amylase in different experimental groups (P>0.05). Based on the results of this experiment and the actual production conditions, the optimum feeding frequency of nutrient fortification in Litopenaeus vannamei broodstock is suggested to be 2 times per day.