used in an overall procedure similar to that commonly used for C. gariepinus and other
species Fermin, 1991.. Fertilized eggs were subsequently spread over submerged
netting in hatching tanks. Hatching occurred within 24 h of fertilization. Two days after
hatching, larvae from two parents were pooled and removed with a tablespoon in groups
of five which were allocated to the treatment containers. Each consecutive allocation
went to a different container until each held exactly 600 larvae at a density of 20
larvaerl. In Experiment 1, a shortage of larvae resulted in only 320 larvae being
available for allocation to each experimental unit. One day was allowed for recovery and
complete yolk absorption. Dead larvae were replaced to maintain a density of 20
larvaerl prior to the start of the experiments. Larvae generally began exogenous feeding
4 days after hatching. All subsequent references to larval or juvenile ages refer to days
after hatching. All experiments began at the onset of exogenous feeding.