Abstract:Oxygen consumption rates (ORs), ammonia excretion rates (NRs), and and oxygen/nitrogen (O/N) ratios of the Haida Golden scallop and Yesso scallop, , were measured seasonally from May 2012 to July 2013 under ambient conditions (5.6℃, 10.5℃, 14.4℃, and 21.2℃) using breathing bottles. The results showed that the variations in OR of and Haida Golden scallop were identical at water temperatures of 5.6-21.2℃. OR increased with temperature when water temperature was < 14.4℃ and decreased with temperature when temperature was > 14.4℃. Maximum ORs of and 1.27 mg/(g·h), respectively. The ORs of Haida Golden scallop were significantly lower than those of < 0.05) but not different at 10.5℃ and 21.2℃( and Haida Golden scallop differed. The NR of increased with temperature and peaked at 14.4℃ (0.063 mg·g-1·h-1) and then decreased. NR at 14.4℃ was higher than those at 10.5℃ and 21.2℃( < 0.05). The NR of Haida Golden scallop decreased from 5.6℃ to 10.5℃ and reached the minimum value at 10.5℃[0.029 mg/(g·h)] but then increased with temperature and peaked at 21.2℃. The NR of Haida Golden scallop was higher than those of at14.4℃( > 0.05). The of OR decreased with temperature. The O/N ratio showed that lipids and carbohydrates were the main Haida Golden scallop consumed protein at low temperature, switched to lipid and carbohydrates when the temperature increased, but switched back to protein when the temperature was highest.