Cannibalism is a clear example of a predatory trait between similar species in a population that is triggered by aggressiveness. This study definitively shows that increasing serotonin in the body can suppress aggressiveness. 5-HTP (oxitriptan) is the name of the substance used in the study to achieve this, as it acts as a precursor for forming serotonin. The serotonin pathway is a hormonal pathway that reliably reduces aggressive behaviour. The study will evaluate the effect of oxitriptan on cannibalism of juveniles sea bass. The research method was an experimental, completely randomised design, with 5 treatments and 3 replications for each. It did not include l-tryptophan and oxitriptan (K), 5% l-tryptophan/g fish (T5), 5 µg oxitriptan/g fish (O5), 10 µg oxitriptan/g fish (O10), and 15 µg oxitriptan/g fish (O15). The juveniles seabass used were 30 days old, with an average length of 3.48 ± 0.15 cm and an average weight of 1.00 ± 0.1 g. The juveniles are maintained in a flow-through system for 30 days, with a feeding rate of 15%. The results showed that oxitriptan supplementation reduced the level of cannibalism (P<0.05). The 10 µg (O10) treatment was undoubtedly the most effective, reducing cannibalism by 20.67% and improving survival rate by the same amount (P<0.05). Oxitriptan is the solution to reduce cannibalism and increase the survival of juveniles seabass. Keywords: cannibalism, oxitriptan, seabass juvenile, survival rate
This study examines plankton abundance, site characteristics, and plankton associations in silvofishery ponds at the Research Center for Brackish Water Aquaculture and Fisheries Extension in Maros Regency. The water quality and plankton samples were collected from December 2022 to January 2023. The study sites are located in rivers (1), polyculture ponds (2), mangrove reservoirs (3), bait ponds (4), pond canals (5), and fishery loading and unloading sites (6). Sampling locations were determined using the purposive sampling method. A randomized group design with ANOVA analysis was used to compare plankton abundance between locations and observation times. Site characterization was analyzed using principal component analysis (PCA) and the associations between plankton genus and observation time were analyzed using correspondence analysis (CA). The results showed the highest total phytoplankton abundance in week 4 at site 1 (3124 ind/L). In the initial observation, the highest total zooplankton abundance was found at site 1 (508 ind/L). This study also showed that phytoplankton abundance was partially influenced by salinity and NO3, while zooplankton abundance was not affected by all water quality variables. Based on PCA, sites 4 and 2 are characterized by water temperature, pH, and PO4 parameters. Sites 1 and 6 are characterized by salinity, brightness, and NO3 parameters. PO₄ poorly characterizes site 5. showed no deviations in any water quality parameters. Chaetoceros has the highest mass value in the line profile (0.279). The largest mass value of zooplankton (0.501) was from subclass Copepoda. Keywords: correspondence analysis, plankton abundance, principal component analysis, silvofishery, water quality ABSTRAK Penelitian ini mengkaji kelimpahan plankton, karakteristik lokasi dan asosiasi plankton pada tambak silvofishery di Balai Riset Perikanan Budidaya Air Payau dan Penyuluhan Perikanan Kabupaten Maros. Sampel kualitas air dan plankton dikumpulkan dari bulan Desember 2022 hingga Januari 2023. Lokasi penelitian terletak di sungai (1), kolam polikultur (2), waduk bakau (3), kolam umpan (4), kanal tambak (5), dan lokasi bongkar muat perikanan (6). Rancangan acak kelompok dengan analisis ANOVA digunakan untuk membandingkan kelimpahan plankton antara lokasi dan waktu pengamatan. Analisis karakterisasi situs dilakukan menggunakan principal component analysis (PCA) dan hubungan antara genus plankton dan waktu pengamatan dianalisis menggunakan correspondence analysis (CA). Hasil penelitian menunjukkan kelimpahan total fitoplankton tertinggi pada minggu ke-4 di lokasi 1 (3,124 individu/L). Pada pengamatan awal, kelimpahan total zooplankton tertinggi ditemukan di lokasi 1 (508 individu/L). Penelitian ini juga menunjukkan bahwa kelimpahan fitoplankton secara parsial dipengaruhi oleh salinitas dan NO3, sedangkan kelimpahan zooplankton tidak dipengaruhi oleh semua variabel kualitas air. Berdasarkan principal component analysis (PCA), Lokasi 4 dan 2 dicirikan oleh parameter suhu air, pH, dan PO4. Lokasi 1 dan 6 dicirikan oleh parameter salinitas, kecerahan, dan NO3. Lokasi 5 dikarakterisasi secara lemah oleh PO₄. Lokasi 3 tidak ditandai oleh parameter kualitas air apa pun. Chaetoceros adalah fitoplankton dengan nilai massa tertinggi dalam profil garis (0,279). Nilai massa zooplankton terbesar (0,501) berasal dari subkelas Copepoda. Kata kunci: analisis komponen utama, analisis korespondensi, kelimpahan plankton, kualitas air, silvofishery
Spiny lobster (P. homarus) cultivation currently has good prospects due to its high economic value. However, there are obstacles to cultivating sand lobsters, such as the difficulty in providing seeds. The way that can be done to overcome this is by engineering lobsters reproduction. Laserpuncture is a method that can be used to engineer reproduction in sand lobsters by utilizing low wave helium-neon light which provides safe stimulation to accelerate the production of developmental and growth hormones in sand lobsters. Laserpuncture induction was carried out on the eye stalk and ventral part of the female sand lobster. This research used the completely randomized design experimental method with female sand lobster weighing 110 ± 5 g. This research was carried out using 4 treatments with 5 replications of each treatment. The treatments in this study were different durations of laserpuncture induction, including A (2 second induction), B (4 second induction), C (6 second induction), and K (no induction). The analysis in this study was carried out qualitatively and quantitatively which included parameters of absolute weight, absolute length, specific growth rate, length-weight relationship, gonad maturity level, and gonadosomatic index. The results showed that treatment A had the most significant effect compared to other treatments on all parameters, so that optimal laserpuncture induction on female sand lobsters could be applied for two seconds. Keywords: development, growth, induction, laserpuncture, lobster
The increasing global demand for high-protein foods has heightened interest in high-quality fishery products such as abalone. This study examined seasonal variations in magnesium (Mg2+) and potassium (K+) concentrations in natural abalone (Haliotis squamata) tissues, surrounding seawater, and associated Sargassum sp. Sampels were collected during the rainy and dry seasons of 2023 from coastal waters in Pekutatan, Jembrana, Bali. Ion concentrations were measured using atomic absorption spectrophotometry (AAS), and proximate composition was analyzed for both abalone meat and Sargassum sp. Results revealed higher Mg2+ and K+ concentrations in abalone meat and shell during the rainy season. Similarly, Sargassum sp. showed greater ion accumulation during the rainy season, while seawater displayed contrasting trends: Mg2+ levels were higher in the dry season, whereas K+ levels increased during the rainy season. Proximate analysis indicated higher protein (48.03 ± 0.89%) and moisture (21.56 ± 0.90%) contents in abalone meat during the rainy season. In contrast, most nutrient components in Sargassum sp. peaked during the dry season, except for ash content, which was highest during the rainy season (48.94 ± 0.63%). These findings suggest that seasonal changes significantly affect ionic uptake and nutritional quality in aquatic organisms through complex environmental-physiological interactions. Keywords: Haliotis squamata, magnesium, potassium, Sargassum sp., seasonal variation
