Abstract
Spawning of the killifish, Aphanius dispar dispar, have been studied in freshwater under controlled laboratory conditions. Two breeding systems, with cages and without cages, were used to study the fish spawning. Five replicates for each system were used. One male and two females were stocked in each tank for ten weeks. The total production of eggs in the tanks with cage system was 144 eggs and the average egg production per tank per week was 2.88 eggs. 59 fries were hatched and the hatchability rate was 41%. No eggs were found in the tanks without cages probably because of predation by their parents. There was a highly significant (P < 0.0001) difference between the two systems in egg production. It was also observed that the eggs were infected with fungus in the breeding and incubation tanks which reduced the eggs production and hatching rate, and caused fry mortality. The present study revealed that the tanks with cage system was the best method to prevent predation of fish on eggs and fry, and to increase fry production. The Ultra Violet (UV) system is recommended to disinfect water of breeding tanks and incubation jars to eliminate fungal infection of eggs. This will help in mass production of A. dispar dispar eggs and fry for restocking of freshwater bodies for biological conservation of the fish to be used for biological control of mosquito larvae and ornamental purpose.