白鲢仔稚鱼食性与生长的初步研究

A PRIMARILY STUDY ON THE FEEDING HABITS AND GROWTH OF SILVERCARP CULTURED IN POND DURING THE LARVAL STAGES

池塘培育的鲢仔稚鱼（６．８—３２．２ｍｍ）食性可分为浮游动物和浮游植物为主的二个阶段。食性的转化取决于消化系统各器官的发育分化。全长１５ｍｍ左右为食性转化阶段。全长２７．９～３２．２ｍｍ，食性接近成鱼。口宽（ＭＷ）、口高（ＭＨ）与全长（Ｌ）的关系分别为：ＭＷ＝－４０１．９９＋９２．６２Ｌ、ＭＨ＝－２２１．６２＋４９．６６Ｌ；肠长／全长（Ｋ）与全长（Ｌ）的关系为：Ｋ＝－０．１２４８＋０．０７１３Ｌ；第Ⅰ列外侧鳃耙数（ＧＮ）与全长（Ｌ）的关系为：ＧＮ＝－６７．４４＋８．９３Ｌ；全长（Ｌ）体重（Ｗ）和时间（ｔ）的关系分别为：Ｌ＝４．５３７＋１．４１７ｔ、Ｗ＝２．７８５ｅ０．２８７３ｔ。以上回归方程经统计检验均为高度显著相关。

The changed of feeding habits and growth of Silvercarp (Hypophthalmichhysmolitrix) during the larval stages (6.8-32.2mm)have been studied in this paper.The feeding habits of the larvae are mainly divided into zooplankton stage and phytoplankton stage.The changes depend on the development and differentiation of their digestive organs.When the total body length achieves about 15mm(the intestineslength begin to exceedthe.total body length,and the number of first outside gill reaches 55～70),the feedinghabits start to vary.The following regression relations bave been obtained:1)mouth width with total body length: MW=-401. 99+92.62L,r=0. 98412)mouth height with total body length:MH=-221. 62+49.66L,r=0.96943)number of first outside gill with total body length:GN=-67. 44+8.93L,r=0.99264)ratio(between intestines length and total body length)with total body length:K=-0.1248+0.0713L,r=0.98895)total body length with time:L=4.537+1.417t,r=0. 99176)body weigth with time:W=2.785e0.287t,r=0.9923Those relations above are very manifest after statistical check.