Ecology, Environment and Conservation Paper

AGE AND GROWTH STUDIES ON MYSTUS SPECIES (TELEOSTEI : BAGRIDAE) FROM MEHADRIGEDDA STREAM OF VISAKHAPATNAM

L.M. Rao and G. Padmaja

Abstract

While studying the Eco-Biology of four species of Mystus i.e., M. vittatus, M. keletius, M. cavasius and M. gulio from Mehadrigedda Stream of Visakhapatnam, their age and growth studies have also been made following the Petersen's "size frequency analysis method". M. vittatus, M. keletius and M. cavasius occurring away from the mouth of the stream were observed to grow to a maximum size of I 2 cms., where as M. gulio abundant towards the mouth, was found to grow upto I 9 cms. The life span of M. gulio was found to be about 4 years while that of the other three species it was about 2 years. The comparatively faster growth rate of M. gull°, is attributed to the richness of food material in the mouth of the stream and as such M. gull() may be tried as an alternative species for Brackirshwater Culture.