ABSTRACT
The growth performance of Clarias gariepinus cultured in concrete and plastic tanks under different management options/systems were analysed. The study was carried out in a fish farm located at No 4 Akhase street, (Ogida quarters) Egor local government area, Benin city, Edo state.
The experiment was made up of two culture systems (semi intensive and intensive) x 2 culture facilities ( plastic and concrete tanks) x 16 weeks culture period factorial in Completely Randomized Design (CRD). Each treatment was replicated three (3) times. Thus a total of 12 culture units was used.The experimental unit was made up of (6 tanks) 3 concrete tanks (4x5m2) and 3 plastic tanks 2500 liters. One thousand two hundred (1200) post fingerlings i.e 200 post fingerlings/tank was bought from a reputable hatchery and cultured for 16 weeks under semi-intensive system (10 fish/m2), while two thousand four hundred (2400) post fingerlings i.e 400 post fingerling/tank was bought from a reputable fish hatchery and cultured for another 16 weeks under intensive system (20 fish/m2). At the end of the 32 weeks the results from both systems were compared and inference made. Data was analysed using Genstat statistical software 2005 version. All samples were replicated three (3) times. Means were separated using Duncan multiple range test. All data was tested at 5% probability level.
The result shows that fishes under intensive culture system had higher values,(concrete tanks (137.7) and plastic (133.58),compared to those cultured under semi intensive system, concrete tanks (120.16) and plastic (117.8). Generally, concrete tanks had better results in both systems. This could be because of a better feed intake (intensive system (2.08) concrete, and (2.05) plastic tanks, compared to those cultured under semi intensive system (1.26) concrete, and (1.15) plastic tanks) and better FCR (intensive culture system had the better values (1.09) concrete, and (1.15) plastic tanks, compared to those cultured under semi intensive system (1.89) concrete, and (1.96) plastic tanks). D.O levels were higher under intensive culture system concrete tanks (5.181) plastic (5.079) and were within recommended range of pond water compared to semi-intensive culture system, concrete tanks (4.980), plastic tanks (4.977). The result was similar for Nitrite, pH and Transparency. The better result recorded under intensive culture system could be as a result of constant change of water and better management practice. Using profit as an index, concrete tank gave the best economic returns (0.54), followed by plastic tank(0.31) under semi-intensive culture system, this was followed by concrete tank (0.21) and the least was plastic tank (0.12) under intensive system.This simply implies that fish farming ventures was more profitable and viable under semi-intensive system is used compared to intensive system. It also showed that concrete tanks were found to be better than plastic tanks in terms of efficiency and profit. This could be as a result of the cost of feed used under intensive culture which increased the cost of production under intensive culture system compared to semi intensive culture system.
It was concluded from the study that using concrete tanks and constant flushing water enhanced water quality and ensured better growth of fish however, high cost of feed and cost of constant flushing of water was a major problem to the profitability of the intensive system. Hence it was recommended that farmers engage in semi-intensive system for profitability of fish farming which is the main aim of every business man.
