The background adaptation of the skin color in the loach Paramisgurnus dabryanus

Body color change is one of the most important manifestations of fish adaptation to the environment. In this study, the body color change of two kinds of loach (Paramisgurnus dabryanus) with different body colors under five different background colors was first studied. It was found that the color of dorsal skin of gray-black loach changed more than that in the abdominal skin, and the L* value of the dorsal skin on the red, yellow and white backgrounds changed significantly (P 0.05). Furthermore, the dynamic change characteristics and adaptive mechanism of body color in different background colors was studied in a black-white background conversion model. The results showed that the greyscale color decreased from 72.33 ± 2.55–38.22 ± 2.33, the melanocytes changed from dendritic to mass, and the L* value of the back skin increased significantly (P