Use of minute duckweed (

Catfish farming is very profitable because the fish is easy to rear and can be harvested quickly. However, the cost of feed as the most significant component in production costs is currently getting higher. The availability and utilization of alternative feed is an urgent solution in creating sustainable catfish farming. This research was carried out during December 2020 – January 2021 in the Research Center for Limnology, Cibinong, Indonesia, which aims to determine the optimal proportion of minute duckweed (Lemna perpusilla) biomass added as feed supplemental to obtain an optimum growth of catfish fingerlings (Clarias sp.). Catfish were reared for 63 days in nine aquariums with a density of 25 fish per aquarium. The commercial pellet given in the control aquarium was 100% pellet portion (5% of the total fish weight), while in the treatment aquariums were 60% and 40% of the total fish weight. As compensation, fresh duckweed (L. perpusilla) was provided ad libitum. Fish were sampled twice to measure their weight and body length. This study showed that the proportion of duckweed as much as 40% as a supplement for commercial pellets could produce optimal catfish growth

EVALUASI KUALITAS AIR PADA SISTEM RESIRKULASI BUDIDAYA IKAN GURAMI, Osphronemus goramy MENGGUNAKAN PEMODELAN DINAMIKA SISTEM

Perkembangan teknologi dalam pembudidayaan ikan menggunakan sistem resirkulasi sangat cepat dalam beberapa tahun terakhir karena bersifat ramah lingkungan dan memberikan banyak keuntungan yaitu mampu memproduksi ikan dengan kepadatan tinggi. Namun, penurunan kualitas air akibat limbah dari feses dan sisa pakan dapat membahayakan sintasan ikan. Penelitian ini dilakukan untuk mengevaluasi kualitas air, khususnya konsentrasi amonia pada sistem resirkulasi budidaya ikan gurami, Osphronemus goramy melalui pemodelan dinamika sistem. Simulasi pemodelan dilakukan dengan software Vensim PLE menggunakan data sekunder. Selama 30 hari periode simulasi, konsentrasi amonia dalam kolam ikan meningkat sampai dengan hari ke-15, kemudian turun bertahap hingga hari ke-30. Konsentrasi amonia yang aman diperoleh dari laju resirkulasi 50 dan75 L/jam dengan sintasan ikan gurami 95%. Persentase eror sebesar 8,6% dibandingkan dengan data hasil penelitian sebelumnya menunjukkan bahwa model dinamika sistem ini valid dan dapat digunakan untuk pemantauan kualitas air, khususnya amonia, dalam budidaya ikan gurami yang menggunakan sistem resirkulasi.The development of recirculating aquaculture systems (RAS) has been rapidly increased in recent years due to environmental and economic advantages, i.e., the system can support farmed fish at high density. However, declining water quality in RAS could occur as a result of the accumulation and decomposition of fecal and uneaten feed materials that can be harmful to fish. This study was conducted to evaluate water quality, particularly the concentration of ammonia in the recirculation system of gouramy, Osphronemus goramy aquaculture through a system dynamics model. The model simulation was performed via Vensim PLE software using datasets from secondary sources. During the 30-days of simulation period, the ammonia concentration in the fish pond increased until day 15, then decreased gradually until day 30. Safe ammonia concentrations were obtained from recirculation rates of 50 and 75 L h-1 with gouramy survival rate of 95%. The percentage error of 8.6% compared to the previous experimental data shows that the prediction of the developed system dynamics model is valid and acceptable. The model can therefore be used for water quality monitoring, particularly for ammonia concentration in gouramy farming using recirculating aquaculture systems