Development of Fishmeal using Knifefish Chitala ornata
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Date
2015
Journal Title
Journal ISSN
Volume Title
Publisher
Uva Wellassa University of Sri Lanka
Abstract
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.
Description
Keywords
Animal Sciences, Meat, Meat Production, Aquaculture and Fisheries, Food Technology