Highlight Research:The bullet tuna (Auxis rochei) was identified and analysed.The length at first maturity (Lm) of bullet tuna (Auxis rochei) was analyzedThe eligibility status of bullet tuna (Auxis rochei) has been analyzed and estimatedThe LWR curve can be used to estimate age groups of fish compared to the sigmoid curveThe CF cannot be automatically used to estimate fish worth selling AbstractThe bullet tuna (Auxis rochei), BLT or tongkol lisong (Indonesian) is a species of neritic tuna which is one of the target fish for small scale fishers. The problem of bullet tuna fisheries was that it has reached overexploitation and the immature bullet tuna are still caught. This study aimed to assess the population dynamics of the BLT and its size composition caught by small scale fishers in the Indian Ocean, West Nusa Tenggara area was carried out in Bangko-Bangko (West Lombok), Cemplung Beach (South Sumbawa) and Tanjung Luar Fishing Port (East Lombok) between July 2019 and June 2020. The data was derived from the measurement and weighing results of 1,217 BLT collected from the respective collector traders at each sampling location. The growth pattern of BLT was isometric () which meant the ideal body shape (mesomorph) and length at first maturity (FLm) was 31.11 cm. The length-weight relationship curve showed that BLT was in an immature age group (adolescent fish). Meanwhile, the composition of BLT is worth selling (Condition Factor > 1.00), fit for catch (FLc / FLm > 1.00) and worthy of maturity (FLc > FLm), respectively 99.92%, 0.82% and 0.00%. The BLT fish composition indicates that the stocks of resources and populations do not support current sustainable fisheries management.

Acute hepatopancreatic necrosis disease has been a major challenge faced by white shrimp farmers in many shrimp-producing countries inducing Indonesia. The etiological agent of this disease was a virulent strain of Vibrio parahaemolyticus. However, a technology to treat or to prevent the disease infection has not been established yet, and probiont could be a potential approach for this disease. Thus, this study aimed at screening 35 lactic acid bacteria (LAB) that originated from the gastrointestinal tract of wild white shrimp for the production of antivibrio compounds using an agar well diffusion. The result showed that three LAB strains (LAB-1, LAB-2, and LAB-3) showed antivibrio activity indicated by the formation of clearance zone (diameter of >10mm) on the diffusion agar plate. When the extracellular products (ECP) were incubated with proteinase K, the antivibrio activity was disappeared which indicated that the antimicrobial compounds were bacteriocin-like inhibitory substances (BLIS). Phenotypic studies suggest that the LAB were Labctobacillus sp. (LAB-1 and LAB-2), and Enterococcus sp. (LB-3). These results suggest these LAB are potential candidates for preventing V. parahaemolyticus. Infection, although, further assays by in vivo using live white shrimp, are still required.

HighlightBullet tuna (Auxis rochei Risso 1810) has been identified (measured, weighed) and analyzed.The resource status of bullet tuna has been estimated based on body shape and age group.LWR curve is implemented to describe and express the age group of bullet tuna (immature, adult/mature, old)This study has resulted the composition and ratio of bullet tuna that is suitable to be caught, fit for consumption and worthy of maturationAbstractBullet tuna (Auxis rochei Risso 1810) or tongkol lisong (Indonesian) is important for human consumption and health as well as an income source for fishers and coastal communities. Its utilization problems are over exploitation, catch domination by immature groups, and the threatened stock security of the bullet tuna (BLT). This research aimed to determine the status of the prospective parent of bullet tuna caught in the Lesser Sunda region, particularly from the Alas Strait to the Indian Ocean, West Nusa Tenggara (WNT). Meanwhile, the data were collected from July to September 2020 (2nd transitional season) at the Tanjung Luar Fishing Port, East Lombok and a dependent survey method was adopted with sampling, interview, observation, and documentation techniques. Fork length and body weight data were used to estimate the length and weight relationship, growth pattern, condition factor, fish age group, and catch worth. The primary and secondary data were processed quantitatively using several equations. The growth pattern of bullet tuna was minor allometric (b = 2.875), worth selling (K > 1.00), and the majority was adult fish or mature group. The LWR model is . This condition indicates the bullet tuna is worth catching  and worth spawning, so that it is eligible to be a potential broodstock candidate to support a sustainable management of BLT fisheries. Furthermore, fishers have applied the code of conduct for responsible fisheries (CCRF) in supporting the sustainable development goals.

Highlight Research Based on technological and economic dimensions, the sustainability of seaweed cultivation in Ekas Bay was less sustainable (index value lied between 26 and 50). The distance between seed clumps, drying places, seedling binding locations, and warehouses were the most sensitive attributes from technological dimension. Market status, market scale, and target market were the most sensitive attributes from economic dimension   Abstract Indonesia is one of the major countries in the world that produces seaweed. West Nusa Tenggara has become one of the centers of seaweed producers in Indonesia because it has many bays that are used for seaweed cultivation activities. The problem of seaweed aquabusiness is the low productivity of the production unit managed by seaweed farmers. This study aimed to assess the effectiveness and production level of seaweed cultivation technology and the success of seaweed cultivation by seaweed farmers in Ekas Bay based on technological dimensions (17 attributes) and economics (14 attributes). The Rapsewaqua application is used to analyze the sustainability status of seaweed cultivation. Based on the results of the analysis, the index value was 50.08 for the technology dimension and 39.50 for the economic dimension. The result showed that the sustainability of seaweed in Ekas Bay was in the less sustainable category. Spacing between seed clumps, drying area, seedling binding location, and warehouse were the most sensitive attributes on the technological dimension. Market status, market scale, and target market were the most sensitive attributes in the economic dimension. These sensitive attributes need to be improved to support the sustainability of seaweed in Ekas Bay.

Pakan merupakan faktor yang memegang peranan penting dalam kegiatan budidaya ikan.Penelitian ini bertujuan untuk mengetahui persentase penggunaan eceng gondok yang optimal dalam pakan buatan terhadap pertumbuhan benih ikan nila. Penelitian ini dirancang dengan menggunakan metode Rancangan Acak Lengkap (RAL) yang terdiri dari 3 ulangan dan 3 perlakuan.Masing–masing perlakuan ditambahkan eceng gondok 10% (P1), 20% (P2), dan 30% (P3). Benih ikan nila memiliki kisaran berat 0,82-0,91 gram dan kisaran panjang 3,5-4 cm yang ditebar dalam akuarium (40x40x40) cm dengan jumlah benih yang ditebar sebanyak 15 ekor Ikan uji di beri pakan sebanyak 3% dari bobot biomasa dengan frekuensi pemberian tiga kali sehari, yaitu pukul 08:00, 02:00 dan 17:00 WITA. Pengaruh perlakuan pada penelitian ini menujukkan hasil yang berbeda nyata (P>0,5 terhadap berat mutlak, laju pertumbuhan berat harian, pertumbuhan panjang mutlak, dan laju pertumbuhan panjang harian. Perlakuan terbaik diperoleh pada perlakuan P1 dengan pertambahan berat mutlak 0,81±0.04 gr, laju pertumbuhan berat harian 0.65±0.03 %, pertumbuhan panjang mutlak 1 cm ±0.05, dan laju pertumbuhan panjang harian 0.23±0.01.