LARVAL REARING OF AN AFRICAN CATFISH, HETEROBRANCHUS-LONGIFILIS, (TELEOSTEI, CLARIIDAE) - A COMPARISON BETWEEN NATURAL AND ARTIFICIAL DIET

Two feeding experiments were conducted to evaluate growth and survival rates of African catfish (Heterobranchus longifilis Valenciennes, 184 0) larvae fed with different diets: live Artemia nauplii, frozen Artem ia nauplii, live zooplankton (Moina micrura), frozen zooplankton (Moin a micrura), a dry diet based on yeast powder and beef liver, and a com mercial trout starter diet. The larvae were fed in excess, six times p er day every 4 hours, from the onset of exogenous feeding up to an age of 14 days. In both experiments the final mean weight and specific gr owth rate of fish fed live Artemia nauplii were significantly higher t han those of fish fed other diets (p<0.05). Survival rates of fish fed Artemia (live or frozen), Moina micrura (live or frozen) and dry diet did not significantly differ (p<0.05) and ranged from 79 to 92% and 6 1 to 73% for experiment 1 and experiment 2, respectively. The commerci al trout diet led to significantly lower growth and survival rates in comparison to all other diets tested. Although it led to a lower growt h rate than that obtained with Artemia, Moina micrura proved suitable for first feeding of H. longifilis larvae. Locally available in West A frican waters, this cladocera could constitute a valuable alternative for larval rearing when a shortage of Artemia is experienced. The resu lts also showed that the artificial feed based on yeast powder and bee f liver leads to survival rates as high as those obtained with living diets and thus represents a promising way for feeding H. longifilis fr y. However, further studies on the nutritional requirements of the lar vae remain necessary in order to improve the efficiency of dry diet in terms of growth performance.