Browsing by Author "Wijesundera, R.R.M.K.K."

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Efficacy of Aloe vera Against Aeromonas hydrophila in Gold Fish (Crassius auratus)
    (Uva Wellassa University of Sri Lanka, 2016) Dissanayaka, D.M.S.G.; Jagoda, S.S.S de S; Wijesundera, R.R.M.K.K.
    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.
  • No Thumbnail Available
    Item
    Preliminary study of Infectious Spleen and Kidney Necrosis Viral (ISKNV) disease in Asian sea bass (Lutes calcurifer) using histopathological method in Sri Lanka
    (Uva Wellassa University of Sri Lanka, 2018) Ekanayake, U.L.N.S.; Fouzi, M.N.M.; Wijesundera, R.R.M.K.K.; Senevirathna, J.D.M.; Kurukulasuriya, M.S.; Jayaweera, W.R.; Wanasinghe, W.M.L.A.; Sakajamary, V.
    Infectious Spleen and Kidney Necrosis Viral (ISKNV) disease is causing mass mortality in both marine and freshwater fish. Detection of this disease is crucial due to confusing clinical manifestations with many other bacterial and viral diseases. Pathology is one of the old and promising method for confirmatory diagnosis. The present study was carried out to confirm the presence of ISKNV in the cultured marine fish: Asian sea bass by histopathological method. Twenty moribund fish samples of sea bass with the mean weight of 60±20g were collected from cultured ponds in Trincomalee and Chillaw. Fish were selected based on the clinical signs suspected for ISKNV such as dark coloured fish with apathy, abnormal swimming, loss of appetite, pale gills and petechial hemorrhages in the operculum, mandible, fin base and abdomen. Spleen, Kidney, Liver, Gill and Brain samples were fixed in 10% neutral buffered formalin (NBF) for histopathological analysis. The formalinfixed tissues were processed routinely, embedded in paraffin wax, cut at 4 pm, and stained with Hematoxylin and Eosin (H&E). Postmortem finding of the study documented the presence of pale liver, pale gills, splenomegaly and fin rot. Degenerative and necrotic lesions in the kidney (mainly tubular epithelia) were observed in 15 fish (75%). Inflammatory cell (granulocytes, macrophages and lymphocytes) aggregates were observed in 10 fish (50%), while 17 fish (85%) showed degeneration, necrosis and vacuoles in hepatocytes with basophilic intracytoplasmic inclusion bodies. Inflammation of the gills were also observed in 10 fish (50%). This is the first study reporting the presence of ISKNV in the cultured marine fish: Asian Sea bass in Sri Lanka. Further studies are needed to determine the pathogenesis and pathology of ISKNV in different species of fish.
  • No Thumbnail Available
    Item
    Usability of Fish Haematological Parameters as a Biological Indicator for Freshwater Quality in Badulla District
    (Uva Wellassa University of Sri Lanka, 2016) Jayasundara, J.M.N.M.; Liyanage, N.P.P.; Wijesundera, R.R.M.K.K.; Senevirathne, J.D.M.; De Silva, D.P.N.
    Water, the fundamental of life, requires continuous monitoring because water quality deteriorates over time. Fish haematological parameters respond more quickly for environmental changes with more precise results than chemical analysis which conduct periodically. As it is profitable to authenticate eco-friendly method for assessing water quality, this study was conducted to investigate the usability of fish haematological parameters as a bioindicator for assessing freshwater quality. Comparison of physico¬chemical parameters of water quality was done in two inland static water bodies in Badulla district: Horabora and Mapakada reservoirs. Results of present study revealed that Transparency, Total Dissolved Solids, Biochemical Oxygen Demand (BUD), pH, Total hardness and Trace metal (As, Pb and Cu) levels were significantly different between Horabora and Mapakada reservoirs (p<0.05). No statistical difference was found for total alkalinity, Dissolved Oxygen level, and Surface water temperature (p>0.05). Both water bodies were identified as polluted in terms of Universal Water Quality Index, although Horabora reservoir was much more polluted than Mapakada reservoir by resulting higher BOD, Total Dissolved Solids, Total hardness and trace metal levels (Pb and As) with less clear water. Blood from Tilapia (Oreochromis mossambicus), Labeo rohita and Calla catla was used for fish haematology analysis. Red blood cell count was significantly different (p<0.05) between two different water bodies for each fish species. Eosinophil count showed a significant difference among two water bodies (p<0.05). The study revealed that a great possibility exists for using fish haematological parameters as a bioindicator for freshwater quality. Moreover, a multi-year continuous study with elaborated investigation require for clarify trends which may exist between fish haematological parameters with respect to water quality changes. Keywords: Water quality study, Haematology, Tilapia, Eosinophil, Trace metal