Effects of Feeding Frequency on Growth, Survival, and Visible Cannibalism in European Catfish Larvae

The transition from endogenous to exogenous feeding represents an important developmental phase in European catfish (Silurus glanis) larviculture, frequently accompanied by high mortality and sibling cannibalism. However, an appropriate feeding frequency to support growth and survival while minimizing cannibalistic losses remains poorly defined. This study evaluated the effects of four feeding frequencies (4, 6, 8, and 12 times day−1) on growth performance, survival, and visible cannibalism over 15 days in a recirculating aquaculture system at 5 larvae L−1. Larvae were fed ad libitum to apparent satiation at each feeding event; consequently, the total daily feed ration was not fixed across treatments. Feeding frequency significantly affected final body weight, weight gain, final total length, length gain, survival, visible cannibalism, and size uniformity, whereas specific growth rate did not differ significantly among treatments. Larvae fed eight times day−1 achieved the highest final weight (106 ± 11 mg) and survival (77.5 ± 2.5%), while exhibiting the lowest coefficient of variation in final total length (10.40 ± 0.36%) and visible cannibalism (3.0 ± 1.2%). Visible cannibalism decreased from four to eight times day−1 but increased at 12 feedings day−1, which also resulted in lower growth and survival. These findings suggest that feeding eight times day−1 under the apparent satiation regime used in this study provided the most favorable overall response among the tested feeding schedules during the first exogenous feeding period.