Effect of tank colour on growth, survival, stress level, digestive enzymatic activities and body composition of snubnose pompano ( Trachinotus blochii Lacépède) larvae

Abstract

Snubnose pompano (Trachinotus blochii, Lacépède) is a commercially important fish species that shows robust growth in captive environment. Tank colour is an important factor affecting the growth of fish larvae in aquaculture. Although the effect of tank colour has been studied in several fish species, it has not been studied in the snubnose pompano. We aimed to investigate how tank colour affects overall growth, survival, body composition, stress levels and digestive enzyme activities of snubnose pompano larvae at early larval stage and late larval stage. We noted that early–larval–stage larvae showed higher growth, crude protein contents and lower digestive enzyme activities when reared in blue and white tanks. Larvae showed low-stress levels when reared in grey and blue tanks. The same larvae showed low-survival and high-stress levels when reared in red tanks. The late–larval–stage larvae showed high growth and lipids, and low-digestive enzymes activities in white and yellow tanks. The larvae showed high-stress levels and low-ash contents when reared in red tanks. These differences are most likely due to the differences in light intensity inside tanks, which affects the ability of larvae to find and catch prey. Overall, our study sheds new light on cultivation conditions for snubnose pompano larvae. We recommend blue tanks for growing early–larval–stage larvae and white or yellow tanks for late-larval-stage larvae.