Reproductive biology of fringescale sardinella (Sardinella fimbriata Valenciennes, 1847) from Malampaya Sound, Palawan, Philippines

Reproduction is a fundamental biological process that is essential for the continuous survival of fish species. Understanding their early life history and reproductive biology can explain how the population behave over time. A total of 1,238 fish samples were examined to determine the reproductive patterns and period of fringescale sardinella (Sardinella fimbriata) from Malampaya Sound, Palawan, Philippines. Monthly sampling from April 2023 to March 2024 revealed a 1:1 sex ratio. Gonadal examination of the fish revealed the presence of spawning individuals throughout the study period. The minimum size of matured fish observed was 11.0 cm and 11.1 cm for male and female S. fimbriata, respectively. The peak of spawning was April as indicated by the highest calculated GSI of 7.62% and fecundity of 18,465. A smaller peak was again observed in the month of September. The length at maturity was estimated to be 11.4 and 8.8 cm for males and females, respectively. Fecundity ranged between 2,700 to 36,067 eggs per spawn for size class between 11.1-14.8 cm and weight 13.07-31.93 g. Regression analysis between fecundity and morphometric characteristics such as body length, weight, eviscerated weight, and gonad weight revealed a positive correlation. Very low coefficients of determination were computed, ranging between 0.0028-0.1233. A significant association between fecundity and the morphometric variable gonadal weight was observed, as shown by the p-value of 0.0000. These outcomes are valuable data in the formulation of conservation and management strategies for the area. Implementation of appropriate conservation measures, monitoring of environmental parameters, strict enforcement of fishery regulation, coupled with increased environmental awareness and community participation will guarantee the long-term sustainability of the fringescale sardinella population and the preservation and sustainable use of marine biodiversity in Malampaya Sound.