The competition index and growth performance between tilapia (Oreochromis niloticus) and native fish spesies Laut Tawar Lake in polyculture system

Abstract

The polyculture system provides great benefits in cultivation, including increasing the productivity of land aquaculture, utilizing leftover feed, and improve water quality. The aim of this study was to analyze the competition index and growth performance of tilapia (Oreochromis niloticus), depik (Rasbora tawarensis), lemeduk/tengadak (Barbonymus schwanenfeldii) and peres/nilem (Osteochilus kappenii) in the polyculture system. This research was conducted at Fish Seed Center (BBI) Lukup Badak, Pegasing District, Central Aceh Regency on May – June 2020. This study used a completely randomized design consisting of 4 treatments and 3 replications, namely treatment A control (tilapia 150 of fish in monoculture system), treatment B (tilapia: 112 fish and lemeduk: 38 fish), treatment C (tilapia: 112 fish, depik: 38 fish), and treatment D (tilapia: 112 fish, peres: 38 fish). The experimental fish were reared in a happa container with a cage system of size 0.5x0.5x1m. The results showed that tilapia reared in the polyculture system had a significant effect (P <0.05) on growth performance compared to monoculture system (treatment A). The competition index shows a negative value between treatments. The research indicated that the best experimental was treatment B (tilapia: 112 fish and lemeduk: 38 fish) and treatment D (tilapia: 112 fish, peres: 38 fish) can increase growth performance and biomass production in polyculture system. In conclusion that the application of the polyculture system of tilapia was able to increase the value of growth performance and there was no competition between experimental fish.