Impact of increase in temperature and light intensity on development and metamorphosis of hatchery reared silver pompano Trachinotus blochii (Lacepede, 1801) larvae

摘要

The impact of increase in temperature and light intensity on development and metamorphosis of hatchery produced larvae of silver pompano Trachinotus blochii (Lacepede, 1801) was studied. Two sets of larviculture tanks (Set 1 and Set 2) in triplicate were exposed to two different temperatures and varying light intensities. The growth of the larvae from day one to day 25 post-hatch (dph) and metamorphosis were studied. It was found that an increase of 2 degrees C water temperature and increased light intensity significantly reduced the growth. The percentage of growth reduction gradually decreased and got stabilised towards the end of larviculture with a mean reduction of 15%. Further, a delay of three days in metamorphosis was also observed in Set 2. The reduced growth rate coupled with change in pigmentation of larvae can be considered as the resilience response of the larvae to combat temperature and light stress without compromising survival.