PHOTOTACTIC RESPONSE OF SEURUKAN (Osteochilus Sp.) TO DIFFERENT LED LIGHT SPECTRA

Abstract

The use of conventional lamps in light fishing activities entails low energy efficiency and environmental risks, creating a need for Light Emitting Diode (LED) innovation. However, data on the phototactic response of local freshwater fish such as Seurukan (Osteochilus sp.) to LED color spectra remain very limited. This study aimed to analyze and evaluate the positive phototactic preference of Seurukan fish toward five LED light spectra (red, green, blue, yellow, and white). A laboratory experiment was conducted using the preference zone method in a light-isolated aquarium divided into three zones (Zone 1: light exposure, Zone 2: transition, Zone 3: dark). Twenty test fish (5–6 cm) were observed for their presence in Zone 1 for 15 minutes per color treatment at 1-minute intervals, and the data were analyzed using one-way ANOVA followed by a post-hoc test. The results showed that different LED color spectra significantly affected positive phototactic preference (F = 13.66; p < 0.001). The green LED spectrum elicited the highest preference at 65.0% (mean of 13.00 fish), followed by white (47.7%), yellow (42.3%), blue (24.0%), and lowest in red (8.0%). Tukey's HSD test indicated that the response to green LED did not differ significantly from white and yellow LEDs, but differed significantly from blue and red LEDs, attributable to the green-shifted vision physiological adaptation of the freshwater fish retina. These findings provide a biological basis for designing selective, energy-efficient LED-based freshwater fishing devices and for domestication management.