Consistent color preference of largefin longbarbel catfish (Mystus macropterus) across life stages: Implications for aquaculture

Abstract

This study systematically investigated the background color preferences of largefin longbarbel catfish (Mystus macropterus) at different life-history stages and assessed their potential applications in aquaculture practices. The study examined three key developmental stages: 0+, 1+ and 2+ years. It analyzed the selection behavior of M. macropterus in response to six distinct background colors (black, blue, red, white, yellow, and green). The results showed that M. macropterus exhibited a significant preference for black and blue backgrounds at all life-history stages, with this preference remaining consistent across different age groups. This finding challenges the prevailing view that fish color preferences change with life-history stage. Instead, it suggests that the color preferences of M. macropterus are closely related to their stable growth and reproductive strategies, supporting the idea that these preferences constitute a stable “fish personality” across life-history stages. Modulating environmental color is hypothesized to reduce intraspecific aggression in aquaculture environments, thereby providing a direct basis for mitigating aggression and facilitating high-density aquaculture through environmental design. These findings provide novel insights into the behavioral adaptations of M. macropterus and offer practical guidance for optimizing aquaculture environments. This study provides a scientific foundation for future aquaculture management strategies, suggesting that adjusting the background color of aquaculture ponds can simultaneously enhance fish welfare, production efficiency, and economic benefits.