Abstract. Amalia R, Rejeki S, Widowati LL, Ariyati RW. 2021. The growth of tiger shrimp (Penaeus monodon) and its dynamics of water quality in integrated culture. Biodiversitas 23: 593-600. Intensive shrimp culture with high density will have an impact on environmental problems. One of them is the accumulation of organic materials. Integrated Multi-trophic Aquaculture (IMTA) is an alternative effort to reduce the environmental impact of aquaculture activities, which can help maintain the balance of the ecosystem. Seaweed and shellfish in the culture system can improve environmental quality. Therefore, it can assist in optimizing friendly environmental shrimp culture. This study aimed to find out the growth of tiger shrimp and the role of seaweed and blood cockles and its dynamics of water quality. Twelve fiberglass tanks containing 800 L of brackish water and filled with ± 10 cm of clay sediment were arranged randomly. This study used 4 treatments and 3 replications, including treatment A (tiger shrimp), B (tiger shrimp+seaweed), C (tiger shrimp+blood cockle), and D (tiger shrimp+seaweed+blood cockle). The data of tiger shrimp growth was monitored weekly, while the growth of blood cockle and seaweed was collected at the end of the study. The water quality parameters such as DO, pH, temperature, and salinity were monitored daily. Meanwhile, the data of Total organic matter (TOM), total ammonia nitrogen (TAN), NO2, and NO3 were measured weekly. The result of the research showed that the highest specific growth rate (SGR) was treatment D (5.75±0.03% day-1). While the highest SR value was treatment B 90.33±0.58%. However, survival rate (SR) on treatment B did not have a significant difference (p<0.05) with treatment C and D. In general, there was significant interaction (p<0.01) in organic waste parameters (TOM, TAN, NO2, and NO3) for all treatments. In removal rate (RR), treatment D was more effective in reducing TOM (19,20%). Meanwhile, the highest level of TAN reduction was achieved by treatment C (50%). In addition, the highest reduction in nitrite and nitrate variables was in treatment D (40% and 33,33%). In contrast, treatment A got a negative removal rate in all parameters.

The coral reefs’ condition in most regions in Indonesia has been declining due to coral diseases, such as Brown Band Disease (BrBD). A treatment for BrBD involves the use of biological control agents that have antagonistic properties against disease-causing agents. This study aimed to isolate bacteria from healthy hard coral, those associated with BrBD, and those that had bioactivities against BrBD. Sampling and identification of corals and BrBD were carried out in March 2015 at the Marine National Park of Karimunjawa. Bacteria from healthy and infected corals were isolated and purified. The isolates were subjected to antipathogenic assay using overlay and agar diffusion methods. Finally, molecular identification of active bacteria was carried out using the 16S rRNA gene amplification. As many as 57 bacterial isolates were obtained from healthy coral, as well as four bacterial isolates from coral with BrBD symptoms. A total of 15 bacterial isolates (26%) showed antipathogenic activity against BrBD-associated bacteria. Three isolates with the strongest antipathogenic activities, i.e., GAMSH 3, KASH 6, and TAPSH 1 were identified by 16S rRNA gene sequences. The results showed that they were aligned to Virgibacillus marismortui (97%), Oceanobacillus iheyensis (97%), and Bacillus cereus (96%), respectively.

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Abstract. Sarjito S, Amalia R, Sabdaningsih A. 2022. Screening of sponge-associated bacteria to control vibriosis in vannamei shrimp (Litopenaeus vannamei). Biodiversitas 23: 5333-5341. An intensive shrimp culture with a high stocking density causes a higher chance of vannamei shrimp being infected with diseases. The most frequent disease is caused by Vibrio sp. Vibrio might cause a severe production loss in the shrimp culture, leading to larvae and mature stadium mortality at 50%. Therefore, a study on the alternative management of vibriosis disease using biocontrol agents is urgently needed. The sponge is a marine invertebrate that provides as a shelter for microbes to live and symbiosis with the animal. An evident ability of sponge-associated bacteria to produce antimicrobial compounds can be exploited as a biodegradable bio-agent, potentially as a solution to control vibriosis disease in a shrimp. This research aimed to isolate sponge-associated bacteria with vibriosis antibacterial potential. Sampling was done in Tulamben, Bali and Panjang island, Jepara, Indonesia with six sampling sites consisting of 15 sampling points. Moreover, vibriosis bacteria were provided by the laboratory of fish disease at Balai Besar Perikanan Budidaya Air Payau (BBPBAP) Jepara. Totally, 24 and 47 pure cultures were successfully isolated using Zobell 2216E agar medium from Tulamben, Bali and Panjang Island, Jepara respectively. The isolates were tested for antibacterial assay using plug agar diffusion methods. The top eight potential isolates were found in isolate B6.3C, B6.3D, B6.4E, B9.3C, PA.1, PA.4, PC.3, and PH.1 against Vibrio vulnificus, V. anguillarum, V. alginolyticus, V. parahaemolyticus, however there was no activity in V. harveyi. The molecular method was carried out to identify those potential isolates using universal primer 16S rRNA. The BLAST homology showed that all potential antibacterial isolates belong to the family Bacilllaceae, such as Bacillus cereus, Virgibacillus salarius, B. aerius, B. paramycoides, B. thuringiensis, and B. altitudinis. Further research will be carried out on microencapsulation and in vivo tests.

Ikan lele sangkuriang merupakan ikan ekonomis penting yang mempunyai potensi untuk dikembangkan. Metionin merupakan asam amino esensial yang mengandung sulfur digunakan sebagai prekursor kartinin dan protein sehingga dapat meningkatkan pertumbuhan dan berkaitan dengan respon pada ikan. Penelitian ini bertujuan untuk mengetahui pengaruh interval dosis optimal penambahan metionin pada pakan buatan terhadap pertumbuhan dan kelulushidupan benih ikan lele sangkuriang (C. gariepinus). Penelitian ini dilaksanakan pada tanggal 14 Juni - 23 Agustus 2021 di Hatchery Balai Perbenihan dan Budidaya Ikan Air Tawar (PBIAT) Ngrajek, Magelang. Ikan uji yang digunakan adalah benih ikan lele sangkuriang ukuran panjang (4,98+0,03)cm/ekor dan berat (1,55+0,08)g/ekor. Metode yang digunakan adalah eksperimen, Rancangan Acak Lengkap (RAL) 4 perlakuan dan masing-masing 3 ulangan dengan interval dosis metionin yang berbeda, perlakuan A (0%); B (0,18%); C(0,36%,) dan D (0,54%). Hasil penelitian menunjukkan bahwa pengaruh penambahan metionin pada pakan buatan dengan interval dosis yang berbeda pada benih ikan lele sangkuriang berpengaruh nyata (P<0,05) terhadap PER dan SGR, serta tidak berpengaruh nyata (P>0,05) terhadap SR. Dosis optimal penambahan metionin pada pakan buatan benih ikan lele sangkuriang (C. gariepinus) adalah  0,40-0,41%/kg pakan yang menghasilkan PER (1,76%) dan SGR (2,37%/hari).