The Interconnection of Reproductive Biology and Conservation Strategies for the Lesser Spiny Eel in the Progo River Ecosystem

The lesser spiny eel (Macrognathus aculeatus) is a significant species in Southeast Asia's freshwater ecosystems, particularly in the Progo River, Indonesia. This study investigates the reproductive biology of the lesser spiny eel, focusing on size, weight, sex ratio, gonad maturity, fertility, and environmental influences on spawning. A total of 217 eels were sampled, and data on gonadal maturity index (GMI), fecundity, and oocyte size were collected and analyzed. The study found a balanced sex ratio of 0.95:1.0, with significant fluctuations during the spawning season. Female eels averaged 33.4 cm in length and 130.4 g in weight, while males averaged 31.6 cm and 107.7 g. Over 58% of females reached gonadal maturity level IV during peak spawning months, indicating synchronized reproductive cycles. The average fecundity at maturity level IV was 2062 ± 605 grains, with larger oocytes being released during spawning. The findings highlight the importance of hydrological conditions in the reproductive success of lesser spiny eels. The study confirms that environmental factors, such as rainfall and water temperature, significantly influence spawning behavior. The low relative fecundity suggests vulnerability to overfishing and habitat degradation, emphasizing the need for targeted conservation efforts. The lesser spiny eel's reproductive biology is intricately linked to environmental conditions, necessitating comprehensive conservation strategies that include habitat protection and community engagement. By fostering local involvement and awareness, conservation initiatives can enhance the sustainability of this species and its ecosystem, ensuring the long-term viability of the lesser spiny eel in the Progo River.