Water conditions: Throughout the study, fish were maintained under the following water parameters: temperature 24.3 to 30°C; pH 7.8 to 9.0. Water quality was maintained by bio-filtration and total water changes were performed every 15 days, after the first 30 days (weaning).
Spawning conditions: Fish were settled in an 80L aquarium, and allowed to pair naturally. Each formed pair was transferred to its own aquarium containing a plastic plate positioned diagonally, to serve as a spawning surface. After spawning, the eggs were reared artifi- cially. The plastic plate with the eggs attached was transferred to another aquarium and an air