Oxygen consumption and lethal dissolved oxygen level of hybrids of siniperca chuatsi♀ × S. scherzeri♂

Abstract

Oxygen consumption rate (OCR) and lethal dissolved oxygen levels (DO) of the hybrids (225.3 ± 4.6 g) of Siniperca chuatsi ♀ × S. scherzeri ♂, were determined after acclimating the fish to 15, 20, 26 and 30°C for 20 days. The same parameters were measured for hybrids with different body weight (146.8 ± 6.3 g, 234.3 ± 8.4 g, 273.9 ± 3.3 g, 327 ± 5.1 g) at 26 °C. OCR increased significantly (P <0.05) with increasing acclimation temperature between 20-26°C, and decreased with increasing body weight. Final preferred temperature estimated from the Q10 was between 26-30°C. The lethal DO concentration for the hybrids at 30°C was significantly higher (P <0.05) than at other temperatures. OCR over the daily cycle under natural lighting conditions was also determined at 26°C. It showed a circadian rhythm with the lowest point at 0830 and peak rates at 1430. Results show that the hybrid has a higher stress tolerance and higher stocking density than the female parent S. chuatsi and indicate their culture potential in subtropical freshwater regions.