The effect of light intensity on performance of larval pike-perch (Sander lucioperca)

Abstract

In this work performance parameters of larval pike-perch (Sander lucioperca) reared under four different light intensities (100, 500, 1000 and 2500lx) until 21days post hatch (dph) were investigated. As performance parameters change in length and weight, swim bladder inflation, feed consumption, natural mortality, stress induced mortality and RNA-DNA ratio were measured. Aim was to investigate the influence of light intensity on pike-perch performance during the first three weeks of larval rearing. Significant differences were found in natural and stress induced mortality as well as in weight growth. No single light exposure level combined optimal performance of all tested performance parameters. Highest light intensity of 2500lx showed good weight growth but an increase in stress induced mortality. Bright light of 500 and 1000lx intensity was found to improve growth and stress mortality whereas dim light conditions of 100lx showed significantly lower natural mortality. Thus data suggested that most favorable illumination during larval pike-perch rearing comprise a tradeoff between optimal natural mortality under dim light conditions (100lx) or optimal larval growth and stress resistance under bright light conditions (500 and 1000lx). It is shown that high light intensities during larval rearing can be beneficial for pike-perch rearing if offspring supply is not limited.