BACKGROUND: Intensive aquaculture and commercialization production are believed to be needed for improving fish health status and probiotics are candidates to achieve this goal. OBJECTIVES: In this study, we utilized Lactobacillus plantarum and Lactobacillus pentosus as autochthonous food supplementation for biochemical investigation in rainbow trout. METHODS: In the current study, 240 juvenile rainbow trout with an average weight of 15 ± 2 g were randomly divided into four groups with three replications. Group 1, 2, and 3 were fed with 108 CFU/g of L. plantarum, L. pentosus, and the combination of these two probiotics, respectively. The control group was fed with the normal diet, for 60 days (2 % of body weight, 3times per day). Samples were taken at days 0 and 60 and biochemical parameters and hepatic enzymes activity were then investigated. RESULTS: Most biochemical factors had positive changes in the fish fed with probiotics, particularly in L. plantarum group (p < 0.05). Furthermore, the results exhibited a significant decrease in ALP level in the probiotic groups, particularly in L. pentosus group (p < 0.05). Meanwhile, AST enzyme activity in plantarum+pentosus group was higher than that in the other groups (p < 0.05). CONCLUSIONS: The present results indicated the effectiveness of food supplementation with probiotics in fish diet with the preference of probiotic to improve the biochemical factors and hepatic enzymes activity of rainbow trout, Oncorhynchus mykiss.

The zebra-snout seahorse, Hippocampus barbouri, is an economically important marine fish and a potential candidate for aquaculture in Thailand. However, the reproductive ultrastructure of this seahorse is still poorly known. Transmission Electron Microscope (TEM) was used to characterize cellular morphology and ultrastructure of gametogenic stages in both sexes of H. barbouri. Based on morphology of the nucleus and unique characteristics of cytoplasmic organelles, oocytes in the oogenesis process of H. barbouri was classified into three distinct phases: primary growth phase (PG), secondary growth phase (SG) and atretic oocyte phase (AO). The early PG oocytes contained multiple nucleoli in close proximity to the nuclear membrane, showing the formation of cortical alveoli. The cytoplasm of late PG oocytes contained two distinctive cellular structures including lipid droplets and cortical alveoli and was enriched in rough endoplasmic reticulum, ribosome and mitochondria. The follicular complex complelety covered the oocyte at this phase and was classified into four distinct layers including zona pellucida, granulosa cells, basement membrane and theca cells. The yolk-granule formation was firstly observed in the early SG oocytes with well-developed microvilli in the zona pellucida and granulosa cells. During the late SG, the single-layered zona pellucida and the granulosa cells were well-organized. The dilated smooth endoplasmic reticulum and mitochondria were clearly visible in the granulosa cells. The AO oocytes exhibited disorganization of follicular complex. In male H. barbouri, spermatogonia and Sertoli-like cells occupied periphery of the germinal epithelium; however, the spermatocytes and spermatozoa were not observed in the germinal epithelium, possibly due to unique testis characteristics at this stage, season of the samples or aquaculture conditions. Taken together, this study unraveled characteristics of sexual differentiation in the zebra-snout seahorse and would provide benefit to monitor reproductive success of seahorse under aquaculture.

Objective: The study was carried out to investigate the use and impact of veterinary drugs, anti¬microbials, and supplements in commercial aquaculture for fish health management measures in three selected areas of Mymensingh, Bangladesh. Materials and Methods: Data collection was conducted through questionnaire interviews with owners of 50 fish farms and 25 drug shop owners from Trishal, Fulpur, Tarakanda, and Sadar Upazila of Mymensingh district. Results: A total of 15 trade-named veterinary antibiotics and six categories of other compounds were identified in this study. Antibiotics were found as the most used veterinary drugs (80.85%), followed by disinfectants, nutritional supplements, saline, ammonia removal agents, probiotics, and pesticides. These veterinary compounds performances for fish health management were found to vary (10%60%) significantly. Conclusion: This studys findings urge the necessity to produce and approve effective aqua drugs and treatments to ensure farmed fish and public health. [J Adv Vet Anim Res 2021; 8(1.000): 36-43]

Fish can be considered as an ideal food as it contains high protein content, minerals, vitamins and omega 3 fatty acids. Organochlorine pesticides (OCPs) are characterized by their low cost, severe toxicity against a wide array of pests, long duration of action and stability in the environment. OCPs have been used for many years in African countries, particularly in Egypt. Despite being outlawed everywhere, OCPs are still being used illegally. One of the main responsibilities of the food safety and public health sectors is to guarantee the safety and wholesomeness of such food products before they are made available to the general public. In order to determine the residual OCP contents in retailed tilapia, catfish, mullet, saurus, and pagrus, this study was conducted. The obtained results in the current investigation revealed the detection of OCPs at 80%, 50%, 20%, 15%, and 15% in the examined catfish, tilapia, mullet, saurus, and pagrus, respectively. Different OCPs were detected at variable concentrations; however, such concentrations were within the established permissible limits in Egypt. In conclusion, OCPs are still detected in different aquatic species and residual concentrations can be detected in different fish species retailed in the Egyptian fish markets. Therefore, it is highly advised to continuously check for OCP residues in fish.

This study describes the macroscopic and microscopic lesions in farmed rainbow trout (Oncorhynchus mykiss) naturally infected with genetically identified Aeromonas salmonicida, A. hydrophila, and A. veronii species. The genus Aeromonas includes bacteria that naturally inhabit both waterways and organisms. At least 27 Aeromonas species have been identified to date, some of which can cause significant economic losses in aquaculture. As up to 68.8% of Aeromonas isolates may be misidentified in routine biochemical and phenotypic tests, however, reported cases of Aeromonas infection in fish may be wrongly identified. Our findings confirmed that the 3 Aeromonas species studied are associated with septicemia and dermal lesions in rainbow trout.

Water quality is an important part of any aquaculture system. Water provides aquatic animals with oxygen, allows for waste removal, and is the conduit for their food. Similar to all other organisms, fish are heavily influenced and dependent on the characteristics of their environment. Non-optimum water physicochemical parameters as dissolved oxygen, pH, salinity, ammonia, temperature etc. can cause stress to the cultured fish and thus make them more susceptible to disease outbreaks. Nile tilapia is the most cultured fish in Egypt. While its sustainable production is hindered by many obstacles. One of them is the water quality, therefore the hygienic effects of the water parameters are important to be clear in culturing.

Water quality is an important part of any aquaculture system. Water provides aquatic animals with oxygen, allows for waste removal, and is the conduit for their food. Similar to all other organisms, fish are heavily influenced and dependent on the characteristics of their environment. Non-optimum water physicochemical parameters as dissolved oxygen, pH, salinity, ammonia, temperature etc. can cause stress to the cultured fish and thus make them more susceptible to disease outbreaks. Nile tilapia is the most cultured fish in Egypt. While its sustainable production is hindered by many obstacles. One of them is the water quality, therefore the hygienic effects of the water parameters are important to be clear in culturing.

Creation of effective and easy-to-replicate in laboratory conditions culture medium for isolation of salmonella out of water, which could make it possible to increase the safety, authenticity and efficiency of bacteriological study of aquatic medium objects, was realized in the conditions of the Republic of Belarus. In course of the numorous preliminary experiments there was developed an enrichment medium containing the following: nutrient yeast (5 g/l); potassium phosphate monosubstituted (8,6 g/l); sodium hydrate (1,4 g/l); 0,1% brilliant green solution (5 cm3/l); 0,01% solution of crystal violet (10 cm3/l); distilled water (1 l). The analyzed medium was estimated in accordance with the following propertiesd: medium sensitivity; efficiency; inhibition of bacteria growing. Research result showed that the experimental medium was more sensitive in comparison with the selenite one. Studying of the efficiency of the compared media showed that accumulation of test strains of S. enteritidis on the experimental medium was in 10E4 times higher, S. typhi – in 10E3; S. typhiniurium, S. anatum was in 10 times higher than at selenite media. The experimental studies proved that the experimental culture medium for salmonella isolation out of city water and surface water was more sensitive and easier to use than the selenite medium

In the article concept and essence of aquaponic systems for production of ecologically clean agricultural production without waste technologies is set forth. A degree of a level of studies of the given рroblem in the countries of the Europe, America, Australia and other countries is set forth too. The expediency of application of similar systems for fuller use of power resources of plants for production of heat of the electric power, an opportunity of production of agricultural production in urban conditions and on the limited ground areas is proved