Effects of monochromatic lights on the melanophores arrangement in the spotted snakehead fish Channa punctata (Bloch, 1793).

Some freshwater teleost fish have pigment cells whose arrangement and shape are affected by the environment. Natural light has a wide range of light intensity. Fish are sensitive to the background and exposed light colour. Fish body colour is a significant criterion in fixing its market value, whether it is ornamental or edible. By favourable light exposure, a culturist may get a good market value of fish on most ethical grounds. In this study, we recorded the changes in melanophore response with the changes in light colour on Channa punctata. Adult fish were treated with monochromatic lights (darkness, white, blue and red light) for 5 and 28 days. After treatment, their body colour and melanophore size, number, length and the number of dendrites were studied. The results showed a significant influence of monochromatic light on melanophore arrangement in fish skin. The data showed that blue light is appropriate for the overall species colour of photic C. punctata. Continuous black or white light caused severe damage to the fish's appearance.