Condition and relative condition cycles in the tropical glassy perchlet Chanda (=Ambassis)commersonii(Cuv. and Val.) (Pisces: Centropomidae)

Abstract

The seasonal condition (K) and relative condition (K _n ) cycles and their changes with the growth of the fish Chanda commersonii (Cuv. and Val.) for 2 yrs are presented. Better K is shown by the smaller immature and first maturity stages and larger, almost senile groups but they show a K _n factor below '1'. The actively breeding adults show a uniform fail inK but they give comparatively high K _n values (above '1'). These changes in K and K _n with the growth of the fish are clearly reflected in their seasonal cycles also.K cycle would thus appear to follow a pattern of build up and loss of body resources, indirectly following the breeding cycle while the K _n cycle follow the breeding and feeding cycles directly, as shown by their seasonal changes and changes with growth of the fish for 2 yrs. Since only minor deviations from unity occur in K _n factor it furnishes a more sensitive index of somatic difference between age groups, of breeding season and feeding cycle.