A preliminary study on oxygen consumption rate, ammonia excretion rate and asphyxiation point of Barbodes schwanenfeldi The effect of temperature, salinity and body length on ammonia excretion rate of Daphniopsis tibetana Sars Effects of body size and salinity on oxygen consumption rate and ammonia excretion rate of Mactra chinensis Philippi Effects of temperature and body size on oxygen consumption rate and ammonia excretion rate of Monodonta labio