Abstract

Salinity tolerance and osmoregulation of a population of Taeniomembras microstomus were studied. Results indicated that this atherinid fish is extremely euryhaline. Probit analysis revealed that the upper and lower L.D.₅₀ values for salinity were 108‰ and 3.3‰, respectively. Salinity tolerance was apparently independent of acclimation, Taeniomembras microstomus has remarkable hypo-osmoregulatory abilities. The freezing point depression of body fluid varied from 0.558º to 2.729º when fish were exposed to a salinity range of 5-120‰.