Effects of frequency and period of feeding on growth rate and feed efficiency of an African catfish, Heterobranchus longifilis (Teleostei, Clariidae)

The effects of period (day, night) and frequency of feeding (1 to 4 meals or continuous feeding) ongrowth rate and feed efficiency of an African catfish (Heterobranchus longifilis) were studied. The 56 day experiment was realized on fish of 74 g initial mean body weight. With the same feeding ratio (3% of fish body weight/day), fish fed during the night had higher growth rate than those fed during day time; feeding throughout the nycthemeral period did not improve growth rate. The growth rate increased with the feeding frequency irrespective of the feeding period. The higher growth rates (2.36 to 2.64 g.d-1) were observed with continuous feeding. The food conversion ratio were significantly lower for fish fed continuously than those receiving the feeding ration in separate meals. The liver somatic index was higher in fish fed at night than in fish fed at day time. On the contrary, the fat deposition in the abdominal cavity was greater in fish fed during day time and increased with feeding frequency. The carcass analysis confirmed these observations. In practice, it is recommended to feed this fish continuously during the night, since this method of feeding led to the highest growth performance. © 1991 IFREMER-Gauthier-Villars.