Efficacy of Aloe vera Against Aeromonas hydrophila in Gold Fish (Crassius auratus)
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Date
2016
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Publisher
Uva Wellassa University of Sri Lanka
Abstract
Sri Lanka is a pioneer county of ornamental fish industry. Guppy, Goldfish, Swordtail, Moly are some fresh water fish species which have high export potential. Disease is one of the major constraints to the development of the ornamental fish industry and bacterial infections are very common in ornamental fish. Herbal medicines have become cheaper and better alternatives to antimicrobial drugs to treat bacterial infections in fish. Therefore, this experiment was conducted to determine the efficacy ofAloe vera for gold fish growth and against artificially injected A. hydrophila. A. hydrophila was isolated from a septicaemic fish and the identity was confirmed through conventional bio chemical tests and Polymerase Chain Reaction- Restriction Fragment Length Polymorphism (PCR¬RFLP). Fresh and mature A. vera leaves were used for the experiment. Antibacterial efficacy ofA. vera was tested in in- vitro by using A. vera supernatant. To examine in- vivo antibacterial efficacy, A. vera supernatant was combined with commercial fish feed and three different A. vera concentrations, i.e; 250 g/kg, 500 g/kg and 750 g/kg were used with a control. According to the results, there was a positive effect of A, vera against A. hydrophila in-vitro. Original A. vera supernatant had the highest inhibition zone in-vitro. Inhibition zone diameter was decreased with increased dilution. When consider about the in- vivo method, a noticeable increase in body weight and Feed Conversion Efficiency was observed as the A. vera concentration in feed goes up, though the values are not statistically significant. Different levels of mortalities were observed in all groups, but the highest mortality within the observed period was recorded in control group and the lowest in the group fed with highest A. vera concentration.
Keywords: Bacterial infections, PCR- RFLP, Feed conversion efficiency, Antimicrobial drugs, Ornamental fish industry.
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Keywords
fish Industry, Animal Sciences, Aquaculture and Fisheries, Aquatic Resources