Detergents are a chemical product that is commonly used in personal care and household product on a daily basis. Its huge consumption in human activities resulted in the increasing awareness of its toxicity in the aquatic environment due to their active ingredients. Daphnia is a planktonic invertebrate organism that usually found in freshwater ecosystems. It plays an essential part in the lower trophic level of food chains. Because of its sensitivity to various environmental changes, they are generally used as a model organism in toxicology. In the present study, we analyzed the toxic effect of household detergent exposure on Daphnia sp. Four different concentration of detergent (25, 50, 75, and 100 mg.L−1) were prepared and the aquadest was used as control. The mortality of Daphnia was observed for 24 hours. The result showed that the mortality of Daphnia increased along with the increasing concentration of detergent exposures. LC50-24 hours values obtained in this study was 28.89 mg.L−1. This result described that the higher level of detergent in a water body can be harmful to the aquatic organism, especially on Daphnia sp. as predominant food for planktivorous fish.

The purpose of this study was to determine the effect and optimal dose of addition of Moringa oleifera leaf extract on culture media to the growth and content of carotenoids of Dunaliella salina. The research method used was experimental with Completely Randomized Design (CRD) as the experimental design. The treatments used were different doses of Moringa leaf extract, namely A (100% walne media), B (75% Media walne + 25% Moringa leaf extract), C (50% Media walne + 50% Moringa leaf extract), D ( 25% Media walne + 75% Moringa leaf extract), E (100% Moringa leaf extract) with a dose of Moringa leaf extract that is 28 ml (100%) with repetitions 4 times. The results showed that the addition of Moringa oleifera leaf extract had a significantly different effect (P <0.05) on growth. Based on the density of Dunaliella salina showed the best treatment, namely at treatment B (75% walne + 25% Moringa extract). The best specific growth rate is found in treatment B (75% walne + 25% Moringa extract). The carotenoid content after treatment was not significantly different (P> 0.05) so that the carotenoid content in the control (treatment A) had the highest level of 1.39 µg / ml and the lowest was in treatment C of 0.19 µg / ml.

This research aimed to identify types of bacteria existed in nursery rearing pond of catfish (Clarias gariepinus) using closed water system. The observed data include bacterial abundance and diversity in the water and in the fish digestion system, fish growth and water quality. This research was performed in the media of 3 concrete pools with the size of 3 x 1 x 0.8 m3 containing fish stock spreading of 3000 tail / pond. The obtained results showed that the highest abundance of bacteria was found in the surface and the bottom of pond C with the abundance number of   3,0 x 104and 1,2 x 103for aerobic and anaerobic bacteria, respectively. Moreover, it was figured that the dominant bacterial species found in the water and the gastrointestinal tract were from the genus of Bacillus, Clostridium and Lactobacillus. Meanwhile, water quality in the pond was observed in the normal range with the temperatures of 28 - 30 oC, pH (6.0 - 7.0), DO (4.5 - 5.7 ppm), ammonia (0.06 - 0.03 ppm), nitrite (0 ppm) and nitrate (0 - 5 ppm). Keywords: Type of bacteria, catfish (Clarias gariepinus), Closed water system.

Kombucha is a tea beverage obtained from the fermentation of sugared tea by a symbiotic culture of bacteria and yeast. Kombucha is known to have many beneficial effects in health due to its chemical content and a high source of acetic acid and lactic acid bacteria and yeast. This study aimed to investigate the effect of kombucha supplementation in feed on growth performance and feed efficiency of catfish (Clarias sp.). Four hundred fish were distributed randomly into five feeding treatment groups includes a basal diet (control) and kombucha supplementation in the fish diet at 4 mL, 6 mL, 8 mL, and 10 mL/kg of feed. The feed was administered for 30 days. Results showed that the administration of kombucha in feed significantly improved the growth performance of catfish (P<0.05). Fish fed with kombucha supplementation at 8 mL produced the highest weight gain, absolute growth rate, and specific growth rate. Feed conversion ratio and feed efficiency ratio were significantly enhanced in the administration of 8 mL kombucha in a fish diet compared to the control diet. This study indicated that administration of kombucha in fish diet had a potential for enhancing the growth performance and feed efficiency of catfish (Clarias sp.)