Ichthyofaunal community structure after restocking, in the Cacaban Reservoir, Tegal, Indonesia

Increased fishing activities can reduce the abundance of ichthyofauna populations in the Cacaban Reservoir. One effort to increase population abundance is through restocking. Selection of species that are not suitable for restocking will have an impact on the decline of native species. This study aimed to determine the community structure and wealth of native ichthyofauna species after increasing the stock in the waters of the Cacaban Reservoir, Tegal, Indonesia. Samplings were conducted periodically from June to September 2019. Fish samples were taken using gill nets measuring between 1.75 and 2.5 inches, which were installed from 17:00 to 05:00 and placed in 5 different sampling locations. The fish caught were identified and grouped according to the species. Water quality parameters were measured at the ichthyofauna sampling location. 17 species were found from 8 families consisting of 10 native species and 7 species of introduced fish, in a composition of introduced fish and native fish of 69% versus 31%, respectively. The native species were Barbodes binotatus, Barbonymus gonionatus, Rasbora argyrotaenia, Puntius orphoide, Osteochilus vittatus, Oreochromis mosambicus, Channa striata, Clarias batrachus, Mystus nigricep, and Tricogaster tricoptera. The results of water quality measurements indicated that the Cacaban Reservoir is still suitable for fish life, based on the provisions of the Government of the Republic of Indonesia Number 82 per 2001 and on the Indonesian National Standard for fisheries and aquaculture activities.