Tank wall colour and light level affect growth and survival of Eurasian perch larvae (Perca fluviatilis L.)

The influence of interaction between light intensity and tank wall colours on survival and growth of perch larvae (Perca fluviatilis L.) was investiga ted for 15 days after hatching. Three light intensities (250, 400 and 800 I x) and four wall colours (black, dark grey, light grey and white) were used . At the end of the experiment, survival rates ranged between 1% and 26%, a nd varied according to the different treatments (P = 0.0001; df = 11). A gl obal effect of light intensity was detected(P = 0.0001; df = 2) and the hig hest survival rate was observed under 250 Ix. Survival was also influenced by the tank wall colour(P = 0.0001; df = 3): light grey showed the best res ult (17%). The greatest growth in weight and length was observed in tanks w ith light grey and white walls, which were strongly illuminated, while the lowest growth was recorded in the tank with black walls and 250 lx illumina tion. (C) 2000 Elsevier Science B.V. All rights reserved.