COMPARATIVE GROWTH PERFORMANCE OF AFRICAN CATFISH (CLARIAS GARIEPINUS) FINGERLINGS OFFERED DIFFERENT TARGET DIETS

COMPARATIVE GROWTH PERFORMANCE OF AFRICAN CATFISH (Clarias gariepinus) FINGERLINGS OFFERED DIFFERENT TARGET DIETS

ABSTRACT

Aquaculture production is considered the future global solution to declining wild fish capture. However, insufficient production of fish due to lack of affordable quality feeds is a major challenge in aquaculture development. This study investigated the growth performance of fingerlings of African catfish (Clarias gariepinus) fed on experimental diets from sun-dried termites (Macrotermes subhylanus), cockroaches (Periplenata americana), larvae of black soldier fly (Hermetia illucens), desert locusts (Schistocerca gregaria) and polychaetes (Marphysa mossambica) and silver cyprinid (Rastrineobola argentea) as Control diet. Six experimental diets were formulated with three replicates per treatment to contain 40% wheat bran and 60% of sun-dried insects and worms. A total of 720 fingerlings, mean weight 0.362 ± 0.089g were obtained. The experiment was conducted for a period of two months (8 weeks). Water quality parameters were recorded twice a week. The nutritive value of the test diets was determined using Association of Official Analytical Chemists (AOAC) methods. The effect of different diets on specific growth rate (SGR%), survival rate (SR%) and water quality parameters was determined. Correlation analysis was done to determine the relationship between diet and tissue amino acids.

Results indicated that water quality parameters such as temperature, dissolved oxygen and PH were within the acceptable range. The nutritional composition of experimental diets ranged as follows; crude protein: 29.3% - 39.1%, ash: 8.9% - 21.3%, fat: 6.7% - 26.3%, moisture: 6.6% - 11.3%, fibre: 4.7 - 14.2% and carbohydrate: 12.9% - 26.4%. The energy content ranged from 281.1Kcal/100g - 409.5Kcal/100g. The amino acid analyses showed that the experimental diets and fish tissue contained six essential amino acids (histidine, isoleucine, leucine, methionine, phenylalanine, and valine) and six non-essential amino acids (arginine, glutamic acid, hydroxyproline, proline, serine and tyrosine). A highly significant positive correlation was observed between the dietary and the tissue amino acids for both essential and non essential amino acids.

Catfish fingerlings body weight increased progressively throughout the experimental period and was significantly higher at the end of the experiment (Mean= 1.1g) compared to the start of the experiment (Mean= 0.4g). Fingerlings fed on black soldier fly larvae recorded the highest weight gain (401.2%) while fingerlings fed on Polychaetes recorded the lowest (54.2%). No significant variation (P > 0.05) in weight gain was however observed among the fingerlings fed on black soldier fly larvae, cockroach and silver cyprinid (Control diet).

The highest specific growth rate was observed on catfish fingerlings fed on black soldier fly larvae (2.64%) and the lowest on fingerlings fed on polychaetes (0.66%). There was no significance difference (P > 0.05) in specific growth rate of fingerlings fed on black soldier fly larvae and silver cyprinid. The survival rates of catfish fingerlings significantly varied among the different diets with the highest survival observed in fingerlings fed on cockroach diet (70.0%) and the lowest in fingerlings fed on termites (9.2%). No significant variation (P > 0.05) in survival rate was observed in fingerlings fed on termites and polychaetes.

From this study the diets derived from black soldier fly larvae, cockroaches, desert locusts and silver cyprinid contained the recommended range of nutrients necessary for growth of catfish fingerlings. The findings of this study suggest that black soldier fly larvae, cockroach and desert locust can potentially replace silver cyprinid as protein sources in the culture of African catfish. The aforementioned target organisms are cheaply available throughout the year and can be easily harvested by fish farmers for catfish rearing in ponds.