Urea-N excretion was affected by salinity for all species except for the Gulf sturgeon
(Table 3). Channel catfish and goldfish had higher rates of urea-N excretion in higher
salinities, while the other species had lower rates or did not change. In all salinities,
rainbow trout and brown trout urea-N excretion was lower than for the other species. The
highest urea-N excretion was in goldfish adapted to 9x salinity.