Browsing by Author "Wanniarachchi, S.P."

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    Development of Fishmeal from Knifefish Chitala Ornata
    (Uva Wellassa University of Sri Lanka, 2014) Wanniarachchi, S.P.
    The current study was carried out to investigate the possibility of producing a fishmeal using knifefish which could be efficiently used as a protein source in fish feed. Knifefish fishmeal was prepared for the experiment by sun drying the flesh, grinding and sieving. Two experimental diets were prepared as treatment 1 (Peliyagoda fishmeal) and treatment 2 (knifefish fishmeal). Both diets were formulated to contain 30-35% protein. Feeding trial was conducted for male and female guppies (mean initial weight 0.3 ±0.09 g) separately for 20 days. Three replicates were used for each treatment with 30 fish in each tank. Fish were fed three times a day until satiation and fecal material were collected every morning by siphoning. Wet weight and standard length of the fish were measured weekly. FCR, SGR, weight gain, protein digestibility and PER were calculated. Cr2O3 was incorporated in the diets to measure digestibility. Data analysis was done by two-way ANOVA using Minitab 16 software. Results of the study revealed no significant difference in the FCR, SGR, weight gain, protein digestibility and PER between the two treatments at 5% significance level. Hence knifefish fishmeal could be suggested as a possible substitute to Peliyagoda fishmeal. However, it is not efficient to use it as a replacement due to its high cost of production. Key words: Feed conversion ratio, Specific growth rate, Weight gain, Protein digestibility, Protein efficiency ratio
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    Development of Fishmeal using Knifefish Chitala ornata
    (Uva Wellassa University of Sri Lanka, 2015) Wanniarachchi, S.P.; Liyanage, N.P.P.; Epasinghe, E.D.M.
    Knifefish (Chitala ornata) is a freshwater fish introduced to Sri Lanka as an aquarium ornamental fish in 1980’s (Gunawardena, 2007). They were introduced to wild habitat s by accidental release and now found in the rivers and lakes in Colombo and Kalutara districts (Sriyananda, 2004). The predatory nature of the knifefish and its ability to spread fast has posed a threat to native aquatic animals in Sri Lanka, especially to endemic species. At present, knifefish is listed as one of the invasive alien species in Sri Lanka (Gunawardena, 2007). Due to their large size and predatory nature, they have lost demand as aquarium fish and they have no demand as food fish. Hence, in order to eliminate these fish from wild habitats a new use should be introduced which would encourage the fishermen to catch them. In this research the possibility of using knifefish to produce fishmeal which could be used as a protein source in fish feed was evaluated. Knifefish for the experiment was collected from Kalutara area. Large bones and skin were removed and flesh was sun dried for 4-5 days. Dried flesh was ground and sieved to produce fishmeal powder. Two experimental diets were prepared as treatment 1 (containing Peliyagoda fishmeal) and treatment 2 (containing knifefish fishmeal) using the trial and error method. Other ingredients used were wheat flour, soyabean meal, rice bran and fish oil. Both diets were formulated to contain 30-35%. Proximate analysis was done for the ingredients and the two diets. Feeding trial was conducted for 20 days using guppies (2.34 ±0.24 cm), male and female separately. Three replicates were used for each treatment. Length and weight of the fish were measured weekly. At the end of the experiment Feed Conversion Ratio (FCR), Specific Growth Rate (SGR), weight gain and protein efficiency ratio (PER) were determined. Production cost of 1 Kg of each diet was calculated and compared. Statistical analysis was done using two-way ANOVA using minitab16 software. Results and Discussion Proximate compositions of the two diets are shown in Table 01. As shown by table 2 there was no significant difference between mean values of the two treatments with respect to FCR, SGR, weight gain or the PER. There was also no effect of the interaction between the sexes and the treatments on the above parameters (P>0.05) according to the results of the two-way ANOVA. Therefore, it is possible to use knifefish fishmeal as a substitute for Peliyagoda fishmeal in fish diets.