Wide scope for ammonia and urea excretion in foraging Pacific hagfish

摘要: Hagfish (Myxinidae) are jawless, marine vertebrates that feed on decaying carrion drops the ocean floor. Although food consumption rates have not been measured, it is likely hagfish ingest large amounts of protein during such feeding bouts. Thus, they would be expected to a high scope for amino acid catabolism which result in post-feeding ammonia and urea excretion. could also exposed as burrow into decomposing carcasses feeding. The goal present study was determine if foraging Pacific (Eptatretus stoutii) higher capacity than other fish species unload may accumulate their body after Accordingly, (JAmm) urea-N (JUrea) excretion were measured immediately following removal from cylindrical Korean cone-traps, had baited with hake submerged Trevor Channel, off Bamfield, British Columbia. rate JAmm averaged 674 ± 210 µmol N kg−1 h−1 over first 1 h traps, 21-fold greater measurements made non-fed control hagfish. By 4–6 h, 50% lower post-foraging rate, before stabilizing between 48–72 h. Post-foraging JUrea ninefold unfed hagfish, averaging 116 21 2 Over next 24–48 gradually declined, approaching Despite JAmm, plasma total (TAmm) concentrations surprisingly low, 114–226 L−1, but still 4.5 9-fold counterparts. Plasma higher, 1838 376 L−1 fish, unchanged foraging. very factorial (21-fold) compared fishes, suggests excrete arising catabolism, well incidentally taken-up behaviour. relatively important rapidly off-loading arises hydrolysis dietary arginine due ingestion tissue dead or ingested elasmobranchs mammals.