A Preliminary Study Of Zebrafish's (Danio Rerio) Phototaxis Behavior In Different LED Light Fields

Fish phototropism is the theoretical basis for the development of fish-collecting lamps.The wide application of fish-collecting makes fishery resources effectively utilized and protected.In order to adapt to the different phototropism characteristics of fish,fish-collecting lamps have evolved from kerosene lamps and incandescent lamps in the early stage to gold-tungsten lamps,gold-halogen lamps and even LED lamps at the present stage.The early light trapping behavior was mainly used in the fishing of Marine fish.With the in-depth study and practice of the phototactic behavior of fish,the light trapping technology was gradually introduced in the cultivation of freshwater fish.The scale of factory cultivation of freshwater fish is very large,and the light plays a crucial role in its feeding,breeding and incubation.For this part,three lights with different color temperatures,including warm white light?3122 K?,neutral light?4021 K?and cold white light?6567 K?,were used to study the effect of white light on phototaxis of zebrafish in laboratory environment.Zebrafish adapt for 30 minutes in dark environment.After dark adaptation,we open the stimulus of light,record the activity of zebrafish during 30 minutes.The results show that the sensitivity of zebrafish to three color temperatures was:warm white light?5 s?is earlier than cold white light?15 s?,and neutral light?25 s?comes last.The change pattern at number of zebrafish distribution regions is shown as follows:a pattern of“U”model with the distribution is higher in the near light region,lower in the transition region and weak light region,and higher in the far light region.Respectively,the first time of“U”model distribution in the third minute,the second minute and the fourth minute.After a minute exposure,the degree of preference of zebrafish to the three kinds of color temperature light environments is neutral light more than cold white light,and least with warm white light.And zebrafish show strong positive phototaxis after long exposure during 30minute,their phototaxis index was+0.127 in warm white light at30^thminute,+0.04 in neutral light at 30^thminute,and+0.113 in cold white light at25^thminute.Studies have shown that zebrafish are more sensitive to warm white light,but neutral light and cold white light display explosive tendency,the adaptation process of warm white light shows a slow tendency and a stable positive phototropism.This experiment at dark light environment,five artificial lights with different wavelength,as follows:red light?625±5?nm,yellow light?585±5?nm,green light?525±5?nm,blue light?455±5?nm,purple light?400±5?nm,research phototaxis reaction in five kinds of monochromatic light environment and the characteristics of trend or avoidance of the single tail and multiple tail zebrafish with homemade phototaxis experiment device.The results show that the percentage of residence time for single tail zebrafish in the monochromatic light environment was in the order:green light 24.11%,red light 15.02%,purple light 10.35%,blue light 8.87%,yellow light7.96%,green light was significantly higher than yellow light and blue light?P<0.05?,and there was no significant difference between red,yellow,blue and purple light?P>0.05?,the phototaxis rate of multiple tail zebrafish were purple light 21.31%,red light 19.96%,green light 19.58%,blue light 14.07%,yellow light 9.58%,purple light,red light and green light were significantly higher than blue and yellow light?P<0.05?.Either a single tail or multiple tail,the phototaxis response were not obvious in yellow light environment;Selection index of five monochromatic lights indicates that both single tail zebrafish and multiple tail zebrafish tend to blue and green light,on the contrary,they all avoid yellow light,purple and red light tend to avoid only with single tail zebrafish and on the contrary of more tail zebrafish.For five monochromatic light environments,the instantaneous adaptability of zebrafish in turn with green light,red light,purple light,blue light and yellow light.The results show that zebrafish do not like the yellow light environment when the monochromatic light in the dark,and show a strong tendency to purple light,red light,green light,and a moderate preference to blue light.This study can provide basic theory for the future research on the artificial breeding technology of freshwater fish.