Corellation of water quality to the prevalence of ectoparasite in milkfish (Chanos chanos) in Sedati District, Sidoarjo

The management of fish aquaculture need to be considered. The poor quality of water can cause fish being easily stressed, so that can lead a disease in fish. This study aims to determine the prevalence of ectoparasites and knows the correlation between ectoparasites prevalence in milkfish, with the quality of the water contained in Sedati District, like Segoro Tambak Village, Banjar Kemuning, and Tambak Cemandi. The method is descriptive method which determined by specific criteria (purposive sampling). The sampling method was random sampling on each farm. The main parameter is water quality, such as temperature, salinity, pH, brightness, dissolved oxygen, and ammonia. Supporting parameters was the clinical symptoms of milkfish. The results showed that one ectoparasite species infested milkfish, namely Chilodonella with 0.2% total prevalence value of the three villages in Sedati District, the highest prevalence was in Tambak Cemandi, the lowest was in Segoro Tambak 0%, the measurement of water quality in the three villages ranged from temperature 26-27 C, salinity 12-22 ppt, pH 8-8.5, brightness 23-28 cm, dissolved oxygen 2-5 mg / L, ammonia 0.03-0.15 mg / L. There is a positive correlation between temperature, salinity, pH, dissolved oxygen, ammonia, and brightness with the prevalence of Chilodonella.