The objective of the present study was to examine the length-weight relationships and condition factors of snapper Lutjanus russellii, ponyfish Aurigequula fasciata and white-spotted spinefoot Siganus canaliculatus harvested from Ulelhee Bay, Banda Aceh City, Indonesia. These species are the predominant fishes caught by traditional beach trawl in Ulelhee Bay, Banda Aceh City, Indonesia. The sampling was conducted for three months from April to June 2015 at one-week interval. A total of 900 fish samples (300 individuals for each species) were measured for the total length and body weight. The length-weight relationships were calculated using Linear Allometric Model (LAM), while the relative weights (Wr) and Fulton's condition (K) factors were calculated to assess the condition of the fish samples. The results showed that the b value of 3.04 in snapper indicates isometric growth pattern, while ponyfish and white-spotted spinefoot fish had the b values of 1.41 and 1.75, respectively, and these species display an allometric growth pattern. The average Fulton's condition factor (K) of snapper was 3.01 for male and 2.49 for female; female ponyfish has the K value of 2.92 and 2.92 for male. In addition, the average K value of whitespotted spinefoot was 2.61 and 2.59 for female and male, respectively. The relative weight condition factor ranges from 58.73 to 166.09 for snapper, from 70.55 to 129.65 for ponyfish, and from 71.63 to 133.53 for white-spotted spinefoot. In general, the relative weight condition factors tendedto be 100. It is concluded that snapper has isometric growth pattern, while ponyfish and white-spotted spinefoot display the negative allometric growth pattern. The condition factors are in excellent condition and indicate a balance of prey and predator.

Background The objective of the present study was to evaluate the growth performance and feed utilization of African catfish Clarias gariepinus fed a commercial diet and reared in the biofloc system enhanced with probiotic. Methods The treatment was the frequency of probiotic application into the cultured system, namely, 5-day interval, 10-day interval, and 15-day interval for 60 days of experiment. Biofloc culture was grown in an experiment tank (vol. 2000 L) by mixing the probiotic ( Bacillus sp.) 10 mL and molasses 200 mL per liter of water.  The fish was stocked into the biofloc system 7 days after cultured at stocking density of 1000 fish tank -1.  The fish was fed a commercial diet that contains 38% crude protein, twice a day at satiation. The application of probiotic was reperformed after 5 days, 10 days, and 15 days after stocking. Results The study showed that the growth performance, survival, and feed utilization of African catfish were higher in the treatment at 5-day intervals over 60 days. The ANOVA test showed that the application frequency of probiotic into biofloc system of cultured media had the significant effect on the growth performance, survival rate, and feed utilization of African catfish. Conclusion The best growth performance and feed utilization were  found at the application of probiotic into biofloc system at 5-day intervals over 60 days.

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Background: High stocking density and intensive feeding in aquaculture systems lead to the accumulation of organic waste, which results in an increase in ammonia, nitrite, and nitrite concentrations in culture media. Biofloc is a potential technology to overcome this problem. The starter is a crucial carbon source for bacteria in the formation of biofloc. The objective of the present study aimed to explore the best starter of biofloc in a red tilapia Oreochromis niloticus culture system. Methods: A completely randomized design with four levels of treatment was used in this study. The tested starter was (A) control treatment, biofloc without starter, (B) biofloc with molasses starter, (C) biofloc with tapioca starter, and (D) biofloc with sucrose starter. The floc was cultured in 100-L tanks with a salinity of 17 ppt. The tanks were stocked with O. niloticus with a size of 3.71±0.11 cm at a stocking density of 30 fish per tank. The fish were fed on a commercial diet two times a day at satiation for 40 days. The ammonia, nitrite, and nitrite concentrations were measured for an interval of 8 days. Results: The study showed that the NH3-N range was 0.02–0.07 mg L−1 (mean, 0.03 ± 0.02 mg L−1), NO2-N range was 0.20–0.43 mg L−1 (mean, 0.25 ± 0.12 mg L−1), and NO3-N range was 0.90–3.20 mg L−1 (mean, 1.42 ± 1.19 mg L−1). Conclusion: Among the starters tested, molasses was found to be the best for biofloc in tilapia culture.

Kelurahan Delima  terletak di kecamatan Tampan Pekanbaru dan memiliki sumberdaya perairan yang memadai. Di kelurahan tersebut terdapat sekolompok ibu-ibu PKK yang sudah pernah melakukan usaha budidaya ikan dalam kolam secara sederhana dan belum menerapkan sistem budidaya ikan yang efektif. Tujuan dari penyuluhan ini adalah untuk memberikan bekal pengetahuan kepada masyarakat agar mampu   melakukan usaha budidaya ikan secara sederhana dan ramah lingkungan.  Kegiatan “Budidaya ikan dengan manipulasi fotoperiod” dilakukan dengan cara ceramah dengan mengunakan slide dan buku TTG sebagai media ajar. Selain itu juga dilakukan praktek langsung untuk membuat kolam terpal, memelihara ikan patin (Pangasius hypopthalmus) memberi makan, merawat ikan serta mengelola kualitas air pada wadah budidaya ikan. Kegiatan ini dihadiri oleh 25 orang ibu-ibu PKK dari RW VIII. Setelah dilakukan penyuluhan, tingkat pemahaman peserta terhadap materi yang diberikan sekitar 85%. Hasil evaluasi dan monitoring menunjukkan bahwa ibu-ibu PKK di RW VIII tersebut sudah mampu melakukan usaha budidaya ikan dengan manipulasi fotoperiod dengan menggunakan kolam terpal dan kegiatan tersebut dapat berkelanjutan.