Active ammonia excretion in the giant mudskipper, Periophthalmodon schlosseri (Pallas), during emersion

摘要: The main objective of this study was to determine whether active NH4+ excretion occurred in the giant mudskipper, Periophthalmodon schlosseri, during emersion. Our results demonstrated that continual ammonia P. schlosseri 24 hr emersion resulted high concentrations (∼30 mmol l−1) fluid collected from branchial surface. For fish injected intraperitoneally with 8 μmol g−1 ammonium acetate (CH3COONH4) followed by emersion, cumulative excreted significantly greater than control sodium acetate. More importantly, rate at hour 2 CH3COONH4 immersed water as reported elsewhere, greatest change occurring 2. Assuming endogenous production remained unchanged, 33% exogenous through head region, presumably gills, first 6 hr Indeed, 6, concentration increased an extraordinarily >90 mmol l−1. Therefore, our confirm for time can effectively excrete a load on land, and corroborate proposition its gills contributes part tolerance aerial exposure. Only 4.6% detoxified urea. glutamate contents muscle liver also significantly, but glutamine unchanged. J. Exp. Zool. 307A:357–369, 2007. © 2007 Wiley-Liss, Inc.