In intensive shrimp culture, oxygen consumption of shrimp is an important indicator that greatly affects the physiological condition of shrimp as a reared organism. The purpose of this study was to dynamically determine the oxygen consumption of shrimp in intensive culture as well as the variables of water quality and shrimp growth. This research was conducted with the concept of ex-post facto causal design in intensive aquaculture ponds during the shrimp cultivation period. During the shrimp culture period, the rate of oxygen consumption of shrimp is inversely related with the  sigmodial average increase in shrimp body weight. Meanwhile, based on the simulation analysis with the dynamic modeling concept, it is shown that oxygen consumption was linear to the dynamics of  average daily gain and inversely proportional with the increasing rate of shrimp biomass in the ponds. In addition, oxygen consumption rate of shrimp in intensive ponds had a close relationship with water salinity and total organic matter. In conclusion, dynamically, the fluctuation of oxygen consumption rate and average daily gain of shrimp in intensive culture are closely related to the stability of the water quality conditions on the shrimp habitat.

Barriers to cultivation activities are disease attacks, one of which is caused by infection with the bacterium Edwardsiella tarda. Treatment efforts can be made using natural ingredients such as jackfruit (A. heterophyllus) leaves. This study aims to determine the content of antibacterial compounds in the jackfruit (A. heterophyllus) leaves crude extract and their effect on Edwardsiella tarda bacteria in vitro. The inhibition test used disc test with five different concentrations of jackfruit (A. heterophyllus) leaves crude extract with three replications: 75 mg/L, 150 mg/L, 225 mg/L, 300 mg/L and 375 mg/L with a comparison using two types of controls (positive with 5 mg/L chloramphenicol antibiotics and negative with no treatment) using Tryptone Soy Agar (TSA) media and incubated for 2x24 hours. The results of phytochemical screening proved that the jackfruit (A. heterophyllus) leaves crude extract contains flavonoids, alkaloids, tannins and saponins. Treatment E with a dose of 375 mg/L gave the highest inhibition of 7.80 mm and treatment A with a dose of 75 mg/L gave the lowest inhibition of 4.38 mm.  The relationship between the treatment given to the test parameter in the form of the resulting inhibitory power obtained the equation y = 0.0111x + 3.6297 with an R2 value of 0.974 which means 97% of the treatment given in the form of crude extract of jackfruit (A. heterophyllus) leaves affects inhibition of bacteria E. tarda.

Abstract. Akabessy JL, Yahya, Fadjar M, Suprayitno E. 2022. Identification of Tambelo (Bactronophorus thoracites) in Wamesa Waters, Manokwari, West Papua, Indonesia. Biodiversitas 23: 6021-6030. Tambelo, otherwise known as shipworm, is a marine bivalve mollusk comprising 16 genera in the Teridinidae family, of which Teredo is the most frequently mentioned. Furthermore, the only species in the genus Bactronophorus is the wood borer, Bactronophorus thoracites (Teredinidae), which has a wide distribution in the Indo-West Pacific biogeographical region. Identifying shipworm species is difficult due to their high diversity and the limited information about their taxonomic characteristics, which often leads to identification errors by collectors. Papuan people consume tambelo as a substitute for side dishes because they are believed to be able to cure various diseases. Therefore, this study aims to establish by morphology and molecular analysis that tambelo belongs to the B. thoracites of the Teredinidae family. Tambelo was identified using the morphological method of observing the physical characterization of the palette, which is unique between genera. It was collected from a mangrove forest near Wamesa Beach, South Manokwari, Manokwari Regency, Indonesia. Meanwhile, this study adopted PCR, an identification method that uses DNA from a small number of samples and can provide a DNA sample sequence. Morphological analysis based on pallet characterization showed that the characteristics of the tambelo pallet were similar to those of the B. thoracites based on the identification book. In addition, the molecular phylogenetic analysis using two mitochondrial protein-coding genes, cytochrome c oxidase subunit I (COI), showed tambelo was 91% similar to B. thoracites from mangroves environment on the west coast of Peninsular Malaysia, Malaysia.

Production problems related to aquaculture cannot be separated from diseases that can cause death in fish. Efforts to overcome the bacterial disease Edwardsiella tarda can be done by using natural materials such as the leaves of croton (Codiaeum variegatum). This study aimed to analyze the content of active compounds contained in croton leaf extract which is antibacterial against E. tarda bacteria. Inhibition test was performed by dilution method Minimum Inhibition Concentration (MIC test) and agar diffusion (disc test). The MIC test used five concentrations: 1 mg/L, 10 mg/L, 100 mg/L, 500 mg/L, and 1000 mg/L on Tryptone Soy Broth (TSB) media, while the disc test used five doses of croton leaf extract, namely: A (100 mg/L), B ( 200 mg/L), C (300 mg/L), D (400 mg/L) and E (500 mg/L), 2 controls (positive and negative), and three replications on Tryptone Soy Agar (TSA) media and incubated for 2x24 h. The positive control used chloramphenicol (5 mg/L) antibiotic. Croton leaf extract contains several compounds, namely saponins, flavonoids, tannins, steroids, and polyphenols, which are antibacterial and could kill the test bacteria with the highest average inhibition zone results obtained at a dose of E (500 mg/L) of 6.34 mm, while the lowest results were obtained at dose A (100 mg/L) of 3.12 mm.

Highlight Research S. platensis has been analyzed for its productivity. Analysis of the productivity of S. platensis on the use of fish culture wastewater media. S. platensis production can be increased by aquaculture wastewater. Aquaculture wastewater enhances the production of cell density, SGR, biomass, protein, and carotenoid of S. platensis. Abstract Increased productivity of Spirulina sp. in the form of high protein, carotenoids, and biomass content can be achieved by improving its nutrient supply. Inorganic fertilizers are nutrient sources, which are generally used in the culture of this organism on laboratory and industrial scale, but there are several drawbacks, including their high costs and limited availability. Several studies have also reported the use of zarrouk fertilizer as a standard culture medium for Spirulina platensis. Therefore, this study aims to determine the effect and the best concentration of fish culture wastewater treatment in Spirulina platensis culture using biomass, protein content, and carotenoid pigments as indicators. A two-factorial completely randomized designs (CRD) was used in this study, where the factors include the dose of organic waste and Zarrouk fertilizer. The microalgae samples, namely S. platensis were cultured using fresh water. This research consists of two factors. The first factor is the dose of organic waste, and the second factor is the dose of Zarrouk fertilizer. The wastewater treatment consisted of 0, 2, 4, and 6 ml/L, while Zarrouk dosages include 0, 0.5, and 1 ml/L. The best results were obtained from the sample treated with 6 ml/L aquaculture wastewater without the addition of Zarrouk. Furthermore, this treatment gave biomass production of 0.781 g/L, 50.441% protein, and 1.246 mg/L carotenoids. Based on the results, S. platensis culture can be carried out using fish culture wastewater without the addition of Zarrouk fertilizer.