Fish community structure in Sermo Reservoir, Yogyakarta, Indonesia: Initial study on invasive fish species

Abstract

Invasive species are becoming issues in freshwater ecosystems throughout the world including Indonesia. Sermo Reservoir is located in Yogyakarta, Centra Java, was indicated to have invasive species identified as Cichlidae family. The study aimed to assess fish communities’ structure and identified invasive fish in Sermo Reservoir. The research was conducted in Sermo Reservoirs, Yogyakarta, Indonesia on March-October 2019. In total, about 3,084 individuals of 10 fish species belonging to 3 families and 8 genera were captured using a experimental gillnets (mesh size 0.75; 1; 1.5; 2; 2.5; 3 inch) at five stations. The fish community in Sermo Reservoir was dominated by Cichlid fish (98.66%). Red devil (Amphilophus labiatus) and Midas cichlid (A. citrinellus) were dominant species founded in Sermo Reservoir (58.82% and 37.00%, respectively). Another species of cichlid that caught consist of nile tilapia (Oreochromis niloticus), mozambique tilapia (O. mossambicus), and jaguar cichlid (Parachromis managuensis). The study showed that Amphilophus spp. have high dispersal (One-way ANOSIM revealed Amphilophus spp. was not significantly different for spatio-temporal (p>0.05)). SIMPER analysis (p < 0.05) showed that A. citrinellus and A. labiatus had spread throughout the waters and were concentrated in Tegiri station which had more littoral zones.