色温对斑马鱼趋光行为影响的研究

Effects of color temperature on phototaxis behavior of zebrafish Danio rerio

为研究斑马鱼Danio rerio对不同色温光源的选择及趋光反应,采用了暖白光(3122 K)、中性光(4021 K)和冷白光(6567 K)3种不同色温的光源,采用水平光梯度法,在实验室环境下研究了白色光源光照环境对体长2.5~3.5 cm斑马鱼趋光行为的影响。结果表明:斑马鱼对3种色温的瞬时反应强度为暖白光组(5 s)>冷白光组(15 s)>中性光组(25 s);斑马鱼区域分布数量的变化规律表现为近光区较高、过渡区较低、弱光区较低、远光区较高的“U”形分布,3种色温情况下出现“U”形分布的时间分别为3、2、4 min;短时间曝光(1 min)内斑马鱼对3种色温光照环境的敏感程度为中性光组>冷白光组>暖白光组;长时间曝光(30 min)内斑马鱼正趋光性最强,其中,暖白光组第30 min时趋光指数为+0.127,中性光组第30 min时为+0.04,冷白光组第25 min时为+0.113,即暖白光组>冷白光组>中性光组。研究表明,斑马鱼对暖白光光照环境更为敏感,但相较于中性光和冷白光快速反应式的趋向性,暖白光的适应过程表现为缓慢的趋向性,且为稳定的正趋光性。

In this experiment,phototaxis,avoidance index and phototaxis index were determined in zebrafish Danio rerio with body length of 2.5-3.5 cm exposed to three lights with different color temperatures including warm white light(3122 K),neutral light(4021 K)and cold white light(6567 K)in a 240 cm×60 cm×30 cm(water depth of 15 cm)aquarium with black opaque bottom and one transparent side and divided into near light zone,transition zone,weak light zone and far light zone where the zebrafish was acclimatized for 30 minutes in dark environment and then exposed to the stimuli of light,recording the activity of zebrafish during 30 minutes at water temperature of 24℃to evaluate the effect of white light on phototaxis behavior of zebrafish.The results showed that the descending order of instantaneous response intensity of zebrafish to three color temperatures was expressed as warm white light(5 s)>cold white light(15 s)>neutral light(25 s).The changes in regional number of zebrafish distribution were shown as a pattern of“U”model,more zebrafish in the near light zone and the far light zone and less zebrafish in the transition zone and weak light zone.The“U”shaped distribution pattern was observed in 3 min at cold white light,in 2 min at neutral light and 4 min at warm white light,showing neutral light>cold white light>warm white light.The zebrafish showed strong positive phototaxis after long exposure during 30 min,with phototaxis index of+0.127 in warm white light at 30th min,+0.04 in neutral light at 30th minu,and+0.113 in cold white light at 25th min,showing warm white light>cold white light>neutral light.The findings indicate that zebrafish are more sensitive to warm white light,but the fish in neutral light and cold white light display explosive tendency,with slow and stable adaptation process and a positive phototropism in warm white light.