Tri Djoko Lelono, Arief Setyanto, Kristina Marsela, Mihrobi Khalwatu Rihmi, Agus Tumulyadi, Eko Sulkhani Yulianto, Wirastika Adhihapsari, Lisa Nur Hidayah, Wahida Kartika Sari, Siti Nur Qmariyah, Oktiyas Muzaky Luthfi, Andik Isdianto, Desy Setyoningrum
This study investigates the reproductive biology and gonadal histology of Decapterus macarellus in Pondokdadap, East Java, to inform size- and season-based fisheries management. Gonadal maturity stages were identified through combined morphological (Cassie) and histological analysis. The length at first gonadal maturity (Lm) was estimated at 21.08 cm, whereas the length at first capture (Lc) was 20.63 cm, indicating that the current fishery predominantly harvests immature individuals (Lc < Lm). Histological examination of the ovaries revealed five oocyte developmental stages (primary growth, yolk vesicle, vitellogenic, maturation, and post-spawning). Most ovaries were dominated by early oocytes (primary growth and yolk-vesicle stages), with only a small proportion of females reaching advanced maturity stages (III–IV). Oocyte diameters increased from 40.84–56.09 μm at early vitellogenesis to an average of 316.25 μm at stage III, and up to 411.80 μm in fully mature oocytes, while post-ovulatory follicles were not observed in the sampled individuals. The coexistence of multiple oocyte stages within the same ovary confirms asynchronous oocyte development characteristic of batch spawners. Our results show that the current fishery mainly exploits pre-spawning fish and that the combination of Lc < Lm and asynchronous spawning necessitates the implementation of a minimum landing size of at least 21.1 cm, together with the identification of peak spawning periods to design temporal fishery closures. These measures would help protect spawning biomass and support the long-term sustainability of D. macarellus in Indonesian small pelagic fisheries. ©2025 The authors.
Department of Fishery and Marine Resources Utilization, Universitas Brawijaya, Malang, 65145, Indonesia; Coastal Resilience and Climate Change Adaptation Research Group, Universitas Brawijaya, Malang, 65145, Indonesia
