Water Quality Effects on Survival and Weight of Tank-Raised African Catfish (Clarias gariepinus, Burchell, 1822) Fed Commercial and Farm-made Feeds

Abstract

The present study was carried out to assess the effect of water quality on survival and weight of tank-raised Clarias gariepinus fed with commercial and farm-made feeds. Nine hundred juveniles (15.15± 3.48g; 128.366± 9.67mm) were stocked in 09 IBC (Intermediate Bulk Container) tanks (1m3 each) at a density of 100 fish/tank and fed with imported (Le), locally pelleted (Lpe) and locally extruded (Lex) feeds thrice a day for 16 weeks. Water quality parameters (water temperature, suspended particles, turbidity, colour, total dissolved solids, electrical conductivity, pH, dissolved oxygen, nitrates, nitrites, ammonia and phosphates) were measured every fortnightly using standard methods. Survivals were determined from the initial and final counts of studied fish and body weight was determined biweekly using a sensitive electronic balance. Regardless of dietary treatments and rearing period, studied water parameters did not differ significantly (p>0.05) except for Total Dissolved Solids (TDS), electrical conductivity (EC), pH and nitrites (p<0.05). The study also revealed that all the parameters were within acceptable or desirable ranges for fish farming except for dissolved oxygen and ammonia which were below (<3mg/l) and above (>0.05mg/l) optimal recommended ranges respectively. In addition, water temperature, turbidity, total dissolved solids, pH and ammonia had a significant effect (p<0.05) on the survival and weight of African catfish. The study concluded that dissolved oxygen and ammonia could have detrimental effects on studied fish growth. However, the fact that the studied fish were exposed short term in holding water as an exchange of water was carried out every day and a complete exchange every fortnightly with well oxygenated water, significantly contributed in reducing the abnormal contents of dissolved oxygen and ammonia. This implies that if best management practices are respected, the studied feeds will not deteriorate holding tank waters and thus not affect fish productivity.