52 JUNE 2013 • WORLD AQUACULTURE • WWW.WAS.ORG et al. 1995). Parasitic load was almost insignificant when found in intestine. In Cyprinus carpio, the Dactylogyrus minutus of Monogenea and endoparasites, Bothriocephalus acheilognathi and Caryop1hyllaeus laticeps of Cestoda were very common (Kir and Ozan 2007). Nematodes, however, were more common in Labeo rohita, which may be related to species and habitat differences. Cengizler et al. (2001) studied ecto and endo parasites of mirror carp (Cyprinus carpio, L. 1758). Ectoparasites such as Monogenean trematodes (Dactylogyrus and Gyrodactylus elegans), crustacean parasites (Argulus foliaceus), protozoan parasites, (Ichthyophthirius multifiliis and Trichodina nigra), cestodes (Schistocephalus sp. and Caryophylaeus sp.) were also found as endoparasites. Ayotunde et al. (2007) analyzed the stomach contents of African carp Labeo coubie and found an abundance of annelid worms, nematodes, plant tissues, decapods, copepods, Daphnia, some rotifers, insects and insect larvae. Akhter et al. (2007) studied parasites of Hypophthalmichthys molitrix, Cyprinus carpio, Cyprinus idellus, Cyprinus carpio and Puntius gonionotus and isolated parasites from body slime, gills and intestine of the infected fishes. They found 3 protozoan, 2 monogenean, 2 trematoda, 4 cestoda, 2 nematoda, 3 crustacean and 1 insect, while the situation was different in the present study where 3 trematodes and 1 nematode species were found. Seasonal Variation of Parasitic Attacks The prevalence of ectoparasitic infection peaks in winter (December–February). Crustacean parasites are found in winter but not during the rest of the year. Among the myxozoan parasites, Henneguya occurs only during winter. Ichthyophthirius infection occurs only during September–February, when the water temperature was low in comparison to other times of the year. Heavy infestation during winter is a consequence of poor feeding and reduced immunity of the host. High stocking density of fingerlings increases the chance of ectoparasite transmission and disease outbreaks (Hossain et al. 2008). Non-uniformity in the prevalence of parasites suggests that distribution of parasites varies from one habitat to another. This can be related to host-parasite relationship and abiotic factors, such as dissolved oxygen, temperature and pH (Anderson 1992). Ectoparasitic prevalence decreases with the increasing temperature and pH of water. Shallow ponds and stagnant water favor multiplication of ciliates, including Trichodina (Kabata 1985). Trichodina sp. is the most prevalent ectoparasite followed by Dactylogyrus sp. in the Philippines (Lumanlan et al. 1992). In Bangladesh, Trichodina is the most prevalent ectoparasite followed by Myxobolus sp. (Hossain et al. 2008). Bichi and Bizi (2002) noted an infection peak in the rainy season in August, low in dry season in April. Seasonal variation in water quality has an effect on the abundance of pathogens and their ability to survive on a host. Appropriate water quality and proper stocking density should be maintained to minimize the risk of parasitic diseaese. Conclusions Parasite fauna of freshwater fishes has not yet been comprehensively explored in Pakistan. There is sparse information to support to any conclusive recommendation for the control of parasitic diseases in the country. Therefore, comprehensive knowledge of the prevalence of fish parasites and the causative factors and type of environment that promotes their proliferation is of fundamental importance for disease control. Notes Department of Fisheries and Aquaculture, University of Veterinary and Animal Sciences, Lahore 54000, Pakistan. E-mail : muhammad.ashraf@uvas.edu.pk References Anderson, D.P. 1974. Fish immunology. In: S.F. Sneiszko and H.R. Axelrod, editors. Diseases of Fishes. T.F.H. Publication Inc., New Jersey. Anderson, R.C. 1992. Nematodia parasites of verterbrates, their development and transmission. C.A.B International, Willingford, UK. Ayotunde, O.E., N.S. Ochang and B. Okey. 2007. Parasitological examinations and food composition in the gut of feral African carp, Labeo coubie in the Cross River, southeastern Nigeria. Journal of Biotechnology 6 (5):625-630. Banerjee, S. and P.K. Bandyopadhyay. 2010. Observation on prevalence of ectoparasites in carp fingerlings in two districts of West Bengal. Journal of Parasitogical Diseases 34:44-47. Bichi, A.H and A.G. Bizi. 2002. Survey of ecto and endo parasites of fishes of Challawa George Dam. NISEB Journal 2(3):219222. Cengizler, I., N. Aytac, A. Sahan and E. Genc. 2001. Ecto-endo parasite investigation on mirror carp (Cyprinus carpio L. 1758) captured from the river Seyhan, Turkey. European Union Journal of Fisheries and Aquatic Science 18(1-2):87-90. Chauhan, R.S., S.K. Malhotra and V.N. Kapoor. 1981. The distribution and abundance of cestodes in eleven species of teleosts from Garhwal Himalayas with a note on host biology. Himalayan Journal of Science 1(1):15-30. Farhaduzzaman, A.M., M. Manjurul Alam, H. Mosharrof, M. Afzal Hussain and Md. Habibur Rahman. 2010. Prevalence of parasites in the Indian major carp, Labeo rohita (Hamilton) in Rajshahi, Bangladesh. University Journal of Zoology Rajshahi University 28:65-68. Hossain M.D., M.K. Hossain, M.H. Rahaman, A. Akhter and D.A. Khanom.2008. Prevalence of ectoparasites of carp fingerlings at Santaher, Bogra. University Journal of Zoology Rajshahi University 27:17-19. Kabata Z. 1985. Parasites and Diseases of Fish Cultured in the Tropics. Taylor and Francis, London, England. Khanna, S.S. 1975. An Introduction to Fishes. Central Book Depot, Allahabad, India. Kir, I. and T.S. Ozan. 2007. Helminth Infections in Common Carp, Cyprinus Carpio L., 1758 (Cyprinidae) from Kovada Lake (Turkey). Journal Türkiye Parazitoloji Dergisi 31(3):232236. Klesius, P. and W. Rogers.1995. Parasitism of catfish and other farm-raised food fish. Journal of the American Veternary Medical Association 207:1473-1478. (CONTINUED ON PAGE 72)
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