Aquaculture has been known as one of solutions in dealing with food security problem through applying best practices of aquaculture and increasing fish production. In many countries, fish production is considered an essential activity contributing to household income and trade. However, fish feed has an expensive price, and it constitutes 60-70% total cost of production. The objective of this study is to reveal an alternative cheap source for additional ingredients to fish diet formulation of Tilapia larvae (Oreochromis niloticus). 240 fish larvae from local hatchery were used and cultured in 4 aquariums with different dose of protein diet (30%, 35%, 40%, and control). The source of protein diet is Polychaeta Nereis sp which was collected from surrounding Kastela Sea. Nereis sp was processed into dry meal and was added into the feed formulation. The result shows that the useful of 40% protein of Nereis sp gives the highest growth and survival rate of tilapia larvae, which is 44,99 g and 100%. It is followed by 35% and 30% Nereis protein, respectively. It is interesting that protein control which is feed commercial has almost similar growth level as the highest one. Specific growth rate (SGR) is 3,74%-3,79% per day for different protein dose of Polychaeta. Survival rate is 100% for all treatments which means all fish can survive and growth continuously from beginning to the end of the study.

Fish bone is a solid waste that usually found in traditional fish markets of Ternate. The bone fraction contains high minerals such as calcium, phosphorus, and collagen proteins which are important for fish growth. Tuna fish bone waste was processed into dry fish feed and mixed into feed formulation of Tilapia. Four different dose of tuna fish bone powder were applied namely 0%, 1%, 3%, and 5% as mentioned treatment A, B, C, and D. Fish diet were given to Tilapia juvenile for 42 days. Results show that the body weight and specific growth rate are highest in fish which given 3% dose of tuna fish bone than other treatments. It reaches 38.66 g and 9.617% BW/day. The lowest FCR is 1.34 in treatment C and the survival rate is not significantly different among treatments (p>0.05).

This study aims to determine the effect of ocean acidification and temperature on growth, survival, and shell performance of fluted giant clam (Tridacna squamosa). Juvenile fluted giant clam put into an aquarium which is given a combination of CO2 pressure treatment (415, 1000 and 1800 ppm) and temperature (30, 32, and 34°C). Measuring the length, width and height of the shell perform in every two weeks for five times. CaCO3 content and shell strength was test at the end of the study. The best growth of shell length, shell width, and shell height in the treatment of CO2 concentrations of 415 ppm and temperatures of 30°C were 23.28 mm, 11.51 mm and 0.69 mm respectively. Survival live also obtained in the treatment of CO2 concentrations of 415 ppm and temperatures of 30°C and CO2 concentrations of 415 ppm and temperatures of 32°C each of 100%. The strength of the shell and CaCO3 content decreased in the treatment of CO2 concentration and high temperatures. Higher concentration of CO2 and increased temperature negatively affected the growth of length, width, survival of scales, reduced strength and the CaCO3 content of shell.

Water quality management for aquaculture is very important because water is a living medium for aquaculture organisms. One of the technological products that use microbes to create a better environment by breaking down organic matter is probiotics. This study aims to determine the effects of different probiotic administration times on water quality in white leg shrimp culture at a laboratory scale. Juveniles of white leg shrimp with PL27 size were reared for 45 days and given four treatments with probiotics at different times. The result showed that the administration of probiotics with a short period interval had a significant effect on floc volume, absolute growth, survival rate, concentrations of ammonia, nitrate, and nitrite. Provision of probiotics with a short time span tended to reduce the concentration of ammonia, nitrate and nitrite. The difference in time of giving probiotics to bio-floc media increased the growth of white leg shrimp, improved water quality, and reduced the concentration of ammonia (NH3), nitrate (NO3), and nitrite (NO2).

<p>This study was aimed to determine the immersion frequency of recombinant growth hormone (rGH) in the growth stimulation of giant gourami juvenile. A total of 50 larvae at second day after first feeding, was immersed in 30 ppt salt water for 2 minutes, and then transferred into 200 mL of 9 ppt salt water containing 30 mg/L rGH in inclusion bodies form. Immersion was performed for 60 minutes and repeated once a week for two, three, four, and five weeks. As the control, fish was immersed with inclusion bodies without rGH (control-1), bovine serum albumin (control-2), 9ppt saline water without rGH (control-3) and in freshwater (control-4). Fish were kept in 7L aquaria during the first four weeks, transferred into 50L aquaria for two weeks, and then in hapa (2×1×1 m³ in size) for two weeks. The results showed that the highest (p&lt;0.05) average body weight of giant gourami juvenile (2.23±0.19 g) was obtained at four times (four weeks) immersion treatment. Similar body weight of fish in two times (1.72±0.29 g), three times (1.68±0.34 g), and five times (1.81±0.17 g) immersion was obtained. Fish body weight of all controls was lower than the rGH-immersed fish. Average body weight of four time rGH-immersed fish (4.01 g) remained higher than other treatment and control (1.96 to 2.36 g) on 8^th week of fish rearing. Survival of four times (96.67±1.15%), and five times rGH-immersion fish (95.33±4.16%) was similar, and higher than other treatments and controls (77.33 to 89.33%). Thus, higher growth rate and survival of giant gourami juvenile could be achieved by four times rGH immersion.</p> <p><strong> </strong></p> Keywords: recombinant protein, growth hormone, immersion frequency, giant gourami