Please use this identifier to cite or link to this item:
Title: Ammonia as a respiratory gas in water and air-breathing fishes
Authors: Randall, D.J.
Ip, Y.K. 
Keywords: Acid excretion
Ammonia excretion
Nitrogen metabolism
Issue Date: Nov-2006
Citation: Randall, D.J., Ip, Y.K. (2006-11). Ammonia as a respiratory gas in water and air-breathing fishes. Respiratory Physiology and Neurobiology 154 (1-2) : 216-225. ScholarBank@NUS Repository.
Abstract: Ammonia is produced in the liver and excreted as NH3 by diffusion across the gills. Elevated ammonia results in an increase in gill ventilation, perhaps via stimulation of gill oxygen chemo-receptors. Acidification of the water around the fish by carbon dioxide and acid excretion enhances ammonia excretion and constitutes "environmental ammonia detoxification". Fish have difficulties in excreting ammonia in alkaline water or high concentrations of environmental ammonia, or when out of water. The mudskipper, Periphthalmodon schlosseri, is capable of active NH4 + transport, maintaining low internal levels of ammonia. To prevent a back flux of NH3, these air-breathing fish can increase gill acid excretion and reduce the membrane NH3 permeability by modifying the phospholipid and cholesterol compositions of their skin. Several air-breathing fish species can excrete ammonia into air through NH3 volatilization. Some fish detoxify ammonia to glutamine or urea. The brains of some fish can tolerate much higher levels of ammonia than other animals. Studies of these fish may offer insights into the nature of ammonia toxicity in general. © 2006.
Source Title: Respiratory Physiology and Neurobiology
ISSN: 15699048
DOI: 10.1016/j.resp.2006.04.003
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.

Google ScholarTM



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.