Sexual Dimorphism, Reproductive Biology, and Growth Patterns of Sumatran Combtail (<i>Belontia Hasselti</i>, Cuvier 1831) From the Kelekar River, South Sumatra, Indonesia

Sexual dimorphism, reproductive biology, and growth patterns are fundamental knowledge in fisheries studies. This study aimed to analyze the sexual dimorphism, reproductive biology, and growth patterns of Belontia hasselti. Samples were collected in the Kelekar River, South Sumatra, Indonesia. Traditional fishing gear, specifically fish traps (``bubu'' and ``pengilar''), was used to catch fish samples. The samples were transported to the Basic Fisheries Laboratory of the Universitas Sriwijaya for collecting study parameters. A total of 100 B. hasselti were used in this study: 56 males (TL: 8.00-13.24 cm, BW: 9.50-37.49 g) and 44 females (TL: 8.00-13.99 cm, BW: 9.00-38.99 g). The results showed that there were morphometric differences between male and female B. hasselti in CFL, AFL-1, AFL-2, VF-AF, and PrDL characters, but there were no differences in meristic characters. The HSI ranged from 0.46% to 2.71% for males and from 0.57% to 3.30% for females. The GSI for males ranged from 0.05 to 0.57%, while for females it ranged from 0.35 to 11.09%. The gonadal maturity stage for males ranged from I to IV, while for females it ranged from II to V. The sex ratio was 1.19:1.00 (male: female). Fecundity ranged from 1011 to 4370 eggs. Egg diameter ranged from 0.8 to 1.7 mm. The growth pattern of males was positively allometric (y = 0.0125x3.0987, R2 = 0.8182), while females exhibited negatively allometric growth (y = 0.0596x2.4031, R2 = 0.7942). These findings are highly valuable for the implementation of the B. hasselti breeding program.