Influence of temperature on early life stages of silver pompano, Trachinotus blochii

Silver pompano, Trachinotus blochii is an important mariculture species in India and Southeast Asia. Understanding the influence of temperature, the most critical environmental factor on the early life stages is crucial for identifying the optimal rearing temperature for its hatchery production and assessing the species resilience to climate change. This study evaluated embryogenesis, hatching, yolk-sac larval development and survival at four environmental temperatures, 24 ± 0.5 °C, 27 ± 0.5 °C, 30 ± 0.5 °C and 33 ± 0.5 °C in thermostatically controlled 50-L tanks (in triplicates). It was found that higher temperatures significantly (P < 0.05) accelerated embryogenesis and the shortest developmental time was recorded at 33 °C (14.5 ± 2.6 h). A significantly higher hatching rate (P < 0.05) was recorded at 30 °C, this was accompanied by a significantly (P < 0.05) reduced hatching duration at the higher temperatures. The larvae that hatched at 24 °C had highest total length whereas the total larval length recorded at onset of exogenous feeding was significantly (P < 0.05) higher at 33 °C. The larval activity, utilisation of endogenous energy reserves (yolk sac volume and oil globule) was also significantly (P < 0.05) higher at 30 °C and 33 °C. Although some embryonic and larval development parameters were comparable at 30 °C and 33 °C, there was a significant incidence of morphological abnormalities (10.00 ± 4.08 %), reduction in hatching % and survival of yolk-sac larvae at 33 °C. These results indicate that 30 ± 0.5 °C is the optimal thermal environment for rearing of early stages of silver pompano as it minimises developmental abnormalities, optimises survival and enhances the efficiency of its hatchery production.