Effect of feeding frequency on food consumption, growth, size variation, and feeding pattern of age-0 hybrid sunfish

Abstract

Four treatment groups of age-0 hybrid sunfish (female green sunfish Lepomis cyanellus×male bluegill L. macrochirus) were fed to satiation at one of four frequencies (one, two, three or four meals per day) for 30 days. Fish fed three and four times daily showed the greatest consumption and growth rates; food conversion ratios did not differ among the four treatments ( P>0.05). Because growth and food conversion were not enhanced when feeding was increased from three to four times daily, the optimal feeding frequency for growth was considered to be three times per day. However, the extent of inter-individual size variation (% change in CV) declined with increasing number of daily feedings ( P<0.05), suggesting that more frequent feeding may produce fish of more uniform sizes. Daily feeding patterns also changed in response to feeding frequency, indicating that when fish are fed at a particular frequency, knowledge of feeding pattern is necessary so that appropriate food amounts can be supplied at each provisioning. Our results suggest that an optimal feeding frequency should be determined not only on the basis of growth and food conversion efficiency, but also according to influences of daily feeding pattern and the desire to achieve size uniformity.