The Effect of Temperature on Survival, Growth and Feed Conversion of Black Bullhead (Ictalurus melas)

Abstract

This study was conducted to determine the effects of temperature on survival, growth, food ingested and feed conversion of fingerling black bullhead (Ictalurus melas). Fish were maintained for nine weeks in reuse systems under controlled environmental conditions (room temperature: 23-26 °C; 0.4-8.4 lux of continuous light) in Wet Laboratory II at SUNY College at Brockport. Each treatment (water temperature of 16, 22, 28 and 34 °C ± 2 °C) was run in triplicate; 416 fish (10-13 cm length; 6-20 g weight) were used. Two PVC tubes (diameter 8 cm; 33-41 cm long) were placed in each fish holding unit to provide cover and reduce stress. Dissolved oxygen was monitored daily. Total ammonia-nitrogen, nitrite-nitrogen and nitrate-nitrogen were monitored weekly. Fish were fed to satiation once daily with Purina Trout Chow #5. Best survival (90.5 %), growth (124.5 %) and feed conversion (1.1) were observed at 28 °C. Survival (80.7 %), growth (43.4 %) and feed conversion (4.6) were reduced at 22 °C. At 16 °C fish survived well (86.6 %), feed conversion was low (1.4), and growth was relatively good (22.3 %). At 34 °C fish were stressed; survival (59.0 %), growth (29.8 %) and feed conversion (3.0) were poor. "Social appetite" at 22 and 28 °C was normal, but at 16 and 34 °C fish exhibited abnormal behavior.