Effects of water temperature and post-feeding period on postprandial ammonia excretion and oxygen consumption by larval Pacific cod (Gadus macrocephalus) fed rotifers (Brachionus plicatilis).

摘要

Postprandial ammonia excretion and oxygen consumption of 15-d post-hatch larval Pacific cod (Gadus macrocephalus), rotifer-fed (Brachionus plicatilis) since their first feeding, were studied in stationary cultures at 10 degrees C, 13 degrees C, and 16 degrees C for 48 h. Postprandial ammonia excretion and oxygen consumption rates were determined after 2, 4, 6, 8, 10, 12, 18, 24, 36 and 48 hours. The 48-h post-feeding weight-specific ammonia excretion and oxygen consumption rates increased until 4 h postfeeding, decreased to 18 h post-feeding, and remained relatively stable until 48 h post-feeding. The highest weight-specific ammonia excretion and oxygen consumption rates were 215+or-19.8 micro g NH₃-N g-1 h-1 and 1,778+or-55.6 micro g O₂ g-1 h-1 2-4 h post-feeding at 13 degrees C. The higher (P<0.05) resting ammonia and oxygen consumption at 16 degrees C 12-h post-feeding indicate that this temperature is not appropriate for inducing higher growth of rotifer-fed pacific cod larvae.