Survival of Bada (Rasbora sp.) and Daphnia sp. using biofloc from Lake Maninjau as natural feed

Abstract

Biofloc is one of the water bioremediation agents in aquaculture. A consortium of microorganisms in biofloc, which include heterotrophic bacteria, phytoplankton and zooplankton, can also function as natural food sources for aquatic biota. This study aims to investigate the potential of biofloc microorganisms consortium as natural food for commercial fish feed-less aquaculture. The study was conducted using Lake Maninjau water taken from two locations at Lake Maninjau, namely Nagari Sungai Batang and Nagari Maninjau, as test samples. Maninjau Lake was chosen because it had a high content of organic compounds and various microorganisms which could be used as an indigenous biofloc starter. Daphnia sp. and Bada (Rasbora sp.) were used as an experimental biota without periodical additional feed during the trial. The results showed that biofloc could grow well using Maninjau Lake water media. Bada and Daphnia could live in the biofloc system for 20 days without supplementary feeding and afterwards entering the death phase. The decline in the population of Bada and Daphnia was thought to be caused by the decrease of biofloc role as natural feed and its ability in maintaining the water quality.