Journal of Vocational in Aquaculture (JAVA)

Pathogenicity test of Vibrio parahaemolyticus in Pacific white shrimp Penaeus vannamei

2024-10-12T15:50:30+07:00

One of the common diseases affecting the Pacific white shrimp (Penaeus vannamei) culture is vibriosis, caused by infection with Vibrio species, including Vibrio parahaemolyticus. Certain strains of V. parahaemolyticus that carry the PirA and PirB toxins are responsible for causing acute hepatopancreatic necrosis disease (AHPND). This study aimed to assess the pathogenicity of V. parahaemolyticus in P. vannamei using bacterial isolates from different sources. A challenge test was conducted using P. vannamei with an average weight of 0.9±0.1 g, exposed to bacterial concentrations of 10⁴ CFU/mL, as determined by lethal concentration 50% (LC₅₀). The experiment followed a completely randomized design with three treatments and three replicates: a control group (K) of uninfected shrimp, shrimp infected with V. parahaemolyticus from Tasikmalaya, West Java (Vp-1), and shrimp infected with V. parahaemolyticus from Situbondo, East Java (Vp-2). Parameters observed included the confirmation of V. parahaemolyticus and AHPND via polymerase chain reaction (PCR), mortality rate, clinical symptoms, bacterial load, and immune response indicators, including total haemocyte count, phagocytic activity, respiratory burst, phenoloxidase activity, and histopathological examination of the hepatopancreas and intestines. Both Vp-1 and Vp-2 isolates were identified as V. parahaemolyticus AHPND strains, infecting shrimp with clinical signs such as pale hepatopancreas, empty intestines, and lethargic movement. Tissue damage, including extensive necrosis in the hepatopancreas and intestines, was observed, leading to mortality rates of 73.33-81.67% with an average time to death ranging from 24.28 to 65.44 hours postinfection.

Growth Performance, Feed Efficiency and Feed Cost per Gain of Juvenile Redclaw Crayfish Cherax quadricarinatus Fed Different Commercial Diets

2024-10-12T05:24:53+07:00

Aquaculture production is greatly influenced by species growth, feed efficiency, and feed costs. This study aims to evaluate different commercial diets on growth performance, feed efficiency, and feed cost per gain of juveniles redclaw crayfish Cherax quadricarinatus. The study used three treatments triplicate, consisting of Diet A (commercial diet with crude protein 40%), Diet B (commercial diet with crude protein 41%), and Diet C (commercial diet with crude protein 41%). The initial crayfish, with sizes of 0,24 ± 0,03 g and 2,1 ± 0,1 cm, were stocked in nine glass tanks (100 cm × 40 cm × 40 cm) with a stocking density of 50 crayfish m^-2 for 60 days. The crayfish were fed twice daily at 07.00 and 17.00 WIB under a restricted feeding rate of 3% of biomass. The result shows that the final weight, average daily growth, specific growth rate feed conversion ratio, protein retention, and protein efficiency ratio did not differ in each treatment (P>0,05). Besides, the feed cost per gain (FCG) showed that diet B and diet C were better than diet A (P<0,05), with values of IDR 27,679±2,378 kg^-1 and IDR 26,579±2,624 kg^-1, respectively, which means those treatments having better economic value. So, This study concluded that commercial diet C is recommended as feed for redclaw crayfish because it is more economical.

Dynamics of Phytoplankton Abundance on the Growth of Pacific whiteleg shrimp Penaeus vannamei

2024-10-12T05:05:55+07:00

Fluctuations in various pond water quality parameters can lead to low survival rates and suboptimal shrimp growth, ultimately affecting production targets. One of the factors influencing the water quality is the presence of phytoplankton. This study aimed to analyze the dynamics of phytoplankton abundance and composition, as well as their impact on the specific growth rate of Pacific whiteleg shrimp. The method consisted of water sampling, identification and calculation of phytoplankton abundance, water quality measurement, and shrimp growth sampling. The abundance of phytoplankton in the B5 pond ranged from 4.78±4.35 × 10⁵ mL^-1 cells. The abundance of phytoplankton in the B6 pond was approximately 4.14±2.14 × 10⁵ mL^-1 cells. Phytoplankton abundance in the B7 pond ranged from 5.05±3.57 × 10⁵ mL^-1 cells. The abundance of phytoplankton in all ponds fluctuated, and the composition of phytoplankton was in accordance with the standards for all three ponds. Based on the results of the Pearson correlation test, there was no direct relationship between phytoplankton abundance and the specific growth rate.

The Effect of Ectoparasites on Hatchery Business of Red Tilapia Oreochromis sp. in Klaten, Central Java

2024-10-17T22:51:13+07:00

Tilapia fish hatchery in Klaten uses the Dengkeng River as a water source for fish hatchery. The polluted water quality of the Dengklek River has an effect on the increasing number of ectoparasites that can infest tilapia seeds. The purpose of this study to evaluate the effect of ectoparasites on red tilapia in Klaten area, Central Java. This research was conducted at the Freshwater Fish Seed Work Unit, Loka Janti, Klaten. The research sample used red tilapia seeds Oreochromis niloticus measuring ±4-6 cm. Fish sampling was carried out randomly at the Freshwater Fish Seeding Work Unit Loka Janti, Klaten. Sampling was taken as many as 5 samples from 28 semi-permanent ponds. Physical and ectoparasite examinations were carried out on tilapia seeds. The data analyzed included water quality, epidemiology, parasite count measurements, specific growth rates, financial values, and Sensitivity Analysis. Ectoparasites can affect tilapia cultivation activities and cause losses. Fortunately, the ectoparasites in Loka Janti did not cause harm. Tilapia hatchery harvest size 2–3 cm with a selling price of Rp75.00 fish^-1 resulted in an income of Rp426.062.70,00 and a profit of Rp71.814.554,00. The R/C ratio obtained is 1,20, and the payback period is 4,4 years.

The Effect of Different Live Feeds on the Growth Performance of Wild Betta Betta channoides Fry

2024-10-17T22:50:38+07:00

Wild betta fish Betta channoides is an endemic species from East Kalimantan, Indonesia. Currently, wild betta Betta channoides is classified as a species threatened with extinction due to a declining population, caused by environmental damage to its natural habitat. This damage is driven by the construction of the new capital city in East Kalimantan, deforestation for oil palm plantations, and overfishing to meet trade demands. To preserve the existence of Betta channoides, domestication efforts are necessary. Depok Ornamental Fish Cultivation Research Institute has been working on cultivating this species since 2019. However, one of the current challenges is the suboptimal growth of larvae due to the lack of knowledge of suitable life feeds for accelerating fish growth. The aim of this study is to enhance the growth of wild betta fish Betta channoides larvae by providing different types of life feeds. The method used was a completely randomized design (CRD) with four treatments and three replicates: Artemia sp. (K), bloodworms (CD), silk worms (CS), and water fleas (KA). Data were analyzed using SPSS with Duncan's test and the Kruskal-Wallis test. The results showed that feeding with silk worms yielded the optimum outcomes for absolute length growth 0.780 ± 0.020 cm, absolute weight growth 0.272 ± 0.005 g, and survival rate 93.33 ± 5.773%. The data indicated that silk worm treatment had a significant effect compared to the control, bloodworms, and water fleas. The study concluded that different feeds significantly affect growth performance and survival rates, with silk worms producing the highest results.