Lake Poso is one of the ancient lakes in the world. This lake is known to have high diversity of endemic fish. Several exotic fish species have been introduced to increase the fisheries production in the lake. However, it is reported that the introduced fish is one of the causes of the threat of the existence of endemic fish in this lake. This study aimed to obtain the latest information on endemic (Adrianichthyidae, Gobiidae, and Zenarchopteridae), and introduced fish in Lake Poso. The research was carried out from May to July 2019 at 17 stations on the coast and rivers of Lake Poso. Fish were collected using a seine net, tray net, and hook and line. The results showed that there were 13 species of fish belonging to eight families and 11 genera. A total of six endemic fish species were still found in this study, namely Adrianichthys oophorus, Oryzias nebulosus, O. nigrimas, O. orthognathus, Mugilogobius sarasinorum, and Nomorhamphus celebensis. Seven species of introduced fish were found, namely Anabas testudineus, Aplocheilus panchax, Channa striata, flowerhorn (Cichlasoma sp.), Melanocromis auratus, Oreochromis niloticus, and Trichopodus trichopterus. Cichlids (flowerhorn, M. auratus, and O. niloticus) have the potential to be invasive due to their adaptability and ease of reproduction in Lake Poso. Conservation of the fish endemic to Lake Poso must be a serious concern for the government, academics, and the community. Ex-situ conservation can be a strategy to conserve the endemic fish of Lake Poso through controlled captivity.

Poso in Sulawesi, primarily the Lake Poso and Poso River, is known as eel (Anguilla spp.) fishing areas. Therefore, research of eel fishing is required as base information for evaluating and determining policies for its activities. The eel fishing research in the Poso area was conducted through primary data observations, secondary data traces, and interviews from April to June 2021. The fishing activities take place in the Lake Poso and Poso River shore and the rivers of the lake inlets. The fishing gear that contributed greatly to the catch was fence traps and spears. The local community’s fence trap called waya is a unique gear only found in this area, and it is installed in Poso River around the lake outlets. The gears block the rivers to catch downstream migration eels. The spear is fishing gear (including for eels) operated at night in shallow waters, especially in the outlets of Lake Poso. The eel production recorded from the Poso areas for the last four years has been 6.7–15.5 tons per year, and the highest production was in Pamona Puselemba.