鳜鱼不同生长阶段中趋光特性的研究

采用光梯度方法研究了鳜鱼生长发育中对 6种光的趋光特性。结果表明 :鳜鱼 (全长 4.7～10 5 .0mm)在水平光梯度下对 3× 10 -1～ 2× 10 3lx的不同色光表现出不同的趋光反应。平游、开食阶段的鳜苗(全长 4.7～ 5 .8mm)对蓝光以外的各色强光均具有强烈的趋光性 ,其中对黄光的趋光反应最为强烈和稳定 ,最大趋光率为 98.2 7%。随着鳜的生长发育 ,对强光的趋光性逐渐减弱 ,而对弱光的趋光性逐步增强 ,其适宜照度逐渐由强光区移至弱光区。全长 30～ 40mm的夏花阶段是鳜鱼的趋光特性明显转变的过渡时期。鳜鱼在不同照度下的适宜光色不尽相同 ,随其生长 ,弱光区的适宜光色为短波段的蓝、绿光 ,而强光区的适宜光色由长波段的黄、橙、红光移至短波段的绿光

Studies on the Phototactic Characteristics of Mandarin Fish ( Siniperca chuatsi ) during Different Development Stages

In this paper a photogradient method was used to study the phototactic characteristics of mandarin fish (Siniperca chuatsi) to six sorts of lights during different development stages. The results reveal that different phototactic reactions to the different colored lights appear when mandarin fish (the total length ranging from 4.7mm to 105.0 mm) are placed under the horizontal photogradient of 3×10-1～2×103 lx illumination. The fries of mandarin fish ( the total length between 4.7 mm and 5.8 mm), which has just begun to move horizontally and ingest food, show very strong phototxis towards every strong colored lights except the blue one, whese phototactic reaction to yellow light is the strongest and stablest with the langest phototactic rate of 98.27 %. With the development of mandarin fish, the phototaxis decreases under strong illuminations and increases under weak ones, so the preferred light intensities change gradually from strong light regions to weak ones, and its summerling stage with the total length between 30 mm and 40 mm is a transitional period in which their phototaxis changes obviously. With the growth of mandarin fish, the preferred lights, varying under different light levels, are short wave lights in weak light regions such as blue and green lights, but change from long wave lights such as yellow, orange and red lights to green light of the short wave ones in strong light regions.