Effect of salinity on the survival and growth ofChanda (=Ambassis) gymnocephalus (Lac.) fry (Pisces; Centropomidae)

Abstract

The survival and .growth of Chanda (= Ambassisy gynmocephalus (Lac.] fry (8·g ± 0'2mm) collected from Murukumpuzha Lake (9·34%0) for a ninety day period in different salinity grades were studied. A faster rate of growth is exhibited by the fish in the highest salinity grades(22'41 and 28· 51%0)' even though during the first month, growth and health was apparently better in the lower salinity grades (4'11, 10·21 and 16'31%0)' Assimilation efficiency also showed a similar gross picture. Thus in C. gymnocephalusvtu: euryhaline species, the fry show preferred salinity gradients for optimum growth within the fluctuating salinity regime at a stable temperature (26 ± 2°C) and hence may make salinity bound emigrations with growth.