The abundance of alien fish species flowerhorn (Cichlasoma trimaculatum (GÜNTHER, 1867) in its fishing ground area at Lake Mahalona, South Sulawesi

Abstract

Abstract Lake Mahalona is located in Towuti District, South Sulawesi Province. There are 29 species of fish found in Lake Mahalona and most of them are endemic fish. The presence of alien species deliberately or unexpected is one of threats causing the declining of the number of biodiversity in fresh waters. This study aims to determine the relative abundance of alien fish species Flowerhorn in its fishing ground area at Lake Mahalona. The research was conducted from January to June 2021 at six stations. Fish samples were obtained by using gill nets. The total Flowerhorn caught during the study were 15,677, the most caught in January was 3,346 and the least in June was 1,451. The Flowerhorn in January were the most number of fish at Kusapa (735), February and March at Muara (566 and 618), April at Tandumata (593), May and June at Badilla (434 and 375). The highest number and relative abundance of Flowerhorn fish were found at Kusapa in January (735 and 33.23%), while the lowest number and relative abundance of Flowerhorn fish were found at Lengkomali in June (129 and 4.62%). Flowerhorn as a alien fish species is distributed throughout the Lake Mahalona station. Flowerhorn fish occupy a lot of habitats with lots of aquatic plants, sandy and rocky substrates.