<![CDATA[Climbing perch (Anabas testudineus) is a local freshwater fish with considerable potential for aquaculture. The success of seed production is influenced by egg hatching success and larval survival, which can be affected by environmental factors, including light intensity. This study aimed to determine the effect of different light intensities on egg hatching rate, hatching duration, larval survival, and larval deformity of climbing perch and to determine the optimal light intensity. The study was conducted fr 40 days from May to June 2026 at the Fish Seed Center of Pariaman City using a Completely Randomized Design with four treatments and three replications. The treatments consisted of P1 (no light), P2 (500 lumens), P3 (1,000 lumens), and P4 (3,000 lumens), with continuous 24-hour LED illumination during the incubation period. The parameters observed were egg hatching rate, hatching duration, larval survival, larval deformity, and water quality. Data were analyzed using ANOVA at a 95% confidence level, followed by Duncan's test when significant differences were detected. The results showed that different light intensities significantly affected egg hatching rate, hatching duration, larval survival, and larval deformity. The highest egg hatching rate was obtained at 3,000 lumens (91.3 ± 3.2%), while the shortest hatching duration was also recorded at 3,000 lumens (8.1 ± 0.14 hours). The highest larval survival rate was obtained at 1,000 lumens (95.4 ± 3.0%). However, the high survival rate is accompanied by the high rate of defects or deformity. Therefore, overall, high light intensity can accelerate hatching, but it has a negative effect on the quality of the larvae]]>
