The background colour of the fibreglass tanks attributed to their significant correlation
with light intensity and spectrum serves as one of the major factors influencing
growth performance and stress levels of cultured fish. Moreover, it plays a key role in
the successful production of the cultured species, which is challenging under confinement
conditions. On the other hand, Asian sea bass (Lates calcarifer) has received significant
attention among researchers due to its high-profit
value and growing demand
in the global market. Hence, the current study was designed to investigate the effects
of different tank background colours (white, red, black and blue) on growth indices,
body composition, digestive enzymes, haematological parameters, expression of
stress and growth-related
factors in L. calcarifer. Therefore, fish (160.90 ± 6.0 g) were
distributed into 12 fibreglass tanks (250-L)
including four treatments in triplicates and
were reared for 6 weeks. According to the present results, the highest specific growth
rate was observed in fish raised in red-coloured
tank followed by white and black
tanks. Maximum weight gain (WG) and high protein efficiency ratio (PER) were observed
in fish raised in red-coloured
tank followed by white-,
black-and
blue-coloured
tanks, respectively. Modulation of the main digestive enzymes was observed across
four treatments indicating different strategies for the utilization of nutrients by fish.
Fish from red-and
white-coloured
tanks showed a lower level of cortisol and higher
levels of heat shock protein (HSP70) when compared to the other groups. The present
findings indicate that red colour is the most suitable background colour for rearing
Asian sea bass juveniles followed by white colour compared with the other ones.