Influences of temperature on hatching time, exogenous feeding onset, growth performance and survival of Cichlasoma nigrofasciatum larvae

This experiment was carried out to examine the effect of temperature on egg incubation period, exogenous feeding onset, growth and survival of the zebra cichlid , Cichlasoma nigrofasciatum larvae with two replications. Experiment was conducted in four groups of brood stocks with Four temperatures with two replications 22-24 °C, 24-26 °C, 26-28 °C and 28-30 °C. After ovulation brood stocks were kept in aquariums until six hours and egg counting continued 12 hours after viewing the first larvae moving to determine the final number of larvae. Larval rearing was conducted over four months and at the end resulted data were statistically analyzed. Results showed that although the highest percentage of weight gain, daily growth rate and specific growth rate related to the highest thermal treatment (group D) but also the highest percentage of hatching and larvae survival rates observed in group C with a temperature of 28-26 °C treatment so the temperature has been important effect on hatching time, duration of yolk sac absorption, growth factors and survival of zebra cichlid larvae so that increasing of temperature increased growth and reducing the time of hatching and exogenous feeding onset. Statistical analysis showed that there is a significant relationship between the temperature and duration of hatching, temperature and duration of yolk sac absorption and temperature and efficiency of growth and temperature and survival the larvae. The fastest start of feeding was in Group A, the highest percentage of hatching, survival rate and lowest level of Corruption eggs were in Group C. Thus, since that the highest percentage of hatching, lowest level of Corruption eggs and highest of the fish larvae survival occurred at the temperature of 28-260C, seems to be this temperature the best temperature for Cichlasoma nigrofasciatum reproduction.