Pemberian pakan berlebih berdampak pada menurunnya kualitas air yang mengakibatkan pertumbuhan terhambat dan tingkat kelangsungan hidup ikan yang rendah. Tujuan penelitian adalah mengetahui pengaruh pemberian probiotik Lactobacillus sp terhadap laju pertumbuhan dan kelulushidupan ikan lele mutiara yang dipelihara menggunakan sistem bioflok. Dosis probiotik yang digunakan adalah 10, 15 dan 20 ml/kg pakan. Penelitian ini menggunakan metode ekperimen dengan rancangan acak lengkap 4 perlakukan dan 3 kali ulangan. Ikan lele dipeliharan selama 30 hari, pemberian pakan 3 kali sehari dengan FR 5% dari biomassa tubuh. Parameter yang diamati adalah pertumbuhan panjang, kelulushidupan, Feed Convertion Ratio (FCR) dan Spesific Growth Rate (SGR) dianalisa dengan menggunakan ANOVA (P

The main problems faced by fish farmers are waste, uneaten feed and feces.  Which can reduce water quality and have a significant impact on fish growth and survival. This study aims to determine the effect of giving various types of probiotics on the growth rate and viability of Mutiara catfish raised using the biofloc system. We used Lactobacillus sp., Bacillus subtilis, and Nitrobacter as probiotic bacteria. This study used a completely randomized design experimental method with 4 treatments and 3 replications, namely K = probiotic less/control, P1= Lactobacillus probiotic, P2= Bacillus subtilis probiotic, P3= Nitrobacter probiotic. Catfish are reared for 30 days, feeding 3 times a day with FR 5% of body biomass. The parameters observed were absolute length growth, survival, Feed Conversion Ratio (FCR) and Specific Growth Rate (SGR) which were analyzed using ANOVA (P <0.05) and Duncan's test to see the differences between treatments. The results showed that the bacteria probiotic treatment had no significant effect on FCR and fish survival, but had a Lactobacillus sp significant effect on growth in absolute length (3.96 ± 0.06 cm) and the growth rate of daily specific weight (5,45±0,18 %/day).  To increase the length and weight growth of catfish fry, probiotic bacteria of the type Lactobacillus sp. on cultivation media.Key words :biofloc, growth rate, lactobacillus, mutiara catfish, probiotics

Dry land-based catfish fishery is one of the promising rural aquabusiness in Gunungkidul, Yogyakarta. There are several problems in this business, for example, supply-demand balancing, calculation accuracy of production capacity, and equitable profit distribution to each stakeholder. This research aimed to design a closed-loop supply chain of dry-land catfish industrial-fishery model by employing the system dynamics approach. Powesim Studio 7 coupled MINITAB 14 was applied to measure the robustness of the supply chain management system, to predict optimum production capacity, and to balance profit distribution. A financial analysis was also performed to determine business feasibility. Three scenarios of price were created by considering the predicted trend of catfish consumption and formulated three alternative prices by appraising the juvenile fish production, aquaculture practices, local feedstock manufactured by farmers, and fish-by products distributed by small-enterprises. Those consideration units were constructed of four observed models. The highest profit to stakeholder was obtained by scenario III that was directed to increase the juvenile fish price to Rp 240/fish, consumption-sized fish at the price of Rp 18,000/kg, fish-by product at the price of Rp 150,000/kg, and local feed at the price of Rp 9,000/kg. According to financial analysis, the four subsystems in dry land-based catfish aquabusiness were all feasible by BCR>1; PP was 5-9 years, NPV>0, PI>1, and IRR>15%/year. The implementation of the system required synergetic action among policymakers, farmer cooperative, and local innovation centers.