Browsing by Author "Harishchandra, R.D.J."

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Diurnal variation in the feeding patterns and food preferences of Dwarf panchax (Aplocheilus parvus)
(Sri Lanka Association for Fisheries and Aquatic Resources, 2015) Fernando, G.K.A.W.; Jayakody, S.; Wijenayake, W.M.H.K.; Galappaththy, G.N.L.; Yatawara, M.D.M.D.W.M.M.K.; Harishchandra, R.D.J.; Wanninayake, W.M.T.B.; Deniyage, S.L.
The food and feeding studies of fish are useful to explore the possibilities of using them for various purposes such as aquaculture and biological control of problematic organisms. In the current study feeding patterns and diet composition of Aplocheilus parvus (E: Killi fish/Drawft panchax), a common surface feeding predator inhabiting freshwater systems were explored. A. parvus was collected from an abandoned brick pit in Pannala in 2012. Twelve fish were caught every two hours for 24 hours. Plankton net was used to obtain a representative sample of food items present in the system. Gut fullness, total and standard length of fish, total weight and gut weight were determined and using copepod as an arbitrary unit, total numbers of food items of individual fishes were estimated. The time at which active feeding occurred was established from total food particle amount and relative gut weight. Diet of A. parvus mainly consisted of adult or larval stages of insects and copepods. Also, gut had a higher fullness in day time compared to night. The peak gut fullness occurred during 1630 in males whilst females had the peak gut fullness at 1230. Copepods were detected mostly during late morning, whilst insect parts and coleopterans were present in all time periods. Main food items detected in the environment in descending order of abundance were copepods, filamentous algae and insects. This study demonstrated that A. parvus selectively preys on insects compared to other aquatic food sources during day time.
The feeding patterns and food preferences of Aplocheilus parvus: a potential biological control agent for malaria?
(Sri Lanka Association for Fisheries and Aquatic Resources, 2012) Fernando, G.K.A.W.; Jayakody, S.; Wijenayake, W.M.H.K.; Yatawara, M.; Harishchandra, R.D.J.; Deniyage, S.L.; Galappaththy, G.N.L.
The ultimate aim of Anti Malaria Campaign is to eliminate indigenous malaria from Sri Lanka. Better environmental and economic benefits could be achieved by the use of indigenous fish species compared to chemical controlling methods as they have minimum or no impact on the existing aquatic fauna. Aplocheilus porvus is a common indigenous species available in both lotic and lentic systems in wet, intermediate and dry zones and is one of the surface feeding predators. The feeding pattern and food preference of A. parvus was determined to test its efficacy as a biological control agent for malaria larvae. A 24 hour sampling for A. porvus wos conducted (n=12 fish every 2 hours) at a brick pit in Pannala MOH region in Northwestern province positive for potential malaria larvae (Anopheles jomesii, 0.1l6/dip) between September 2011 January 2012. Gut fullness, total and standard length of fish, total weight and gut weight and using copepod as an arbitrary unit, total number of food items per 1ml of dissolved gut was calculated with a Sedgewick Rafter Cell. The time at which active feeding occurred was established from total food particle amount and relative gut weight (gut weight/total weighx100). Diet of A. porvus mainly consisted of adult or larval stages of class Insecta (Coleoptera, Hymenoptera and other unidentified insect parts and insect larvae) and class Maxillopoda (Copepoda). Also, gut had a higher fullness in day time (4.3:t0.121) compared to night (2.4:t0.120) (p