Although high temperature treatment decreased survival and
inhibited the growth of exposed fish during the early treatment
period, the fish later started to increase food consumptions and
growth rate when they were maintained at control temperature.
The average growth was significantly increased in sterile fish at
the end of the experiment. Sexual maturation in Nile tilapia usually
starts at 4–5 months after hatching. The significant growth
difference in the present study corresponded with the onset of sexual maturation. At this stage, the metabolizable energy that was
supposed to be utilized for gonadal development was used for
somatic growth as described for several species of fish
(Basavaraja and Antony, 1997; Dygert, 1990; Majhi et al., 2009b;
Rijnsdorp, 1990). On the other hand, gonadal somatic cells are
capable of producing growth hormone and the gonad may act as
an endocrine organ that produces growth hormone in fish
(Bhatta et al., 2012)