~ 1075 ~ Journal of Entomology and Zoology Studies 2018; 6(5): 1075-1076 E-ISSN: 2320-7078 P-ISSN: 2349-6800 JEZS 2018; 6(5): 1075-1076 © 2018 JEZS Received: 04-07-2018 Accepted: 05-08-2018 Inam Ullah Department of Zoology Wild life and Fisheries, University of Agriculture Faisalabad, Punjab, Pakistan Muhammad Fiaz Khan Department of Zoology, Hazara University, Mansehra, Pakistan Muhammad Seyab Khan Department of Zoology, Hazara University, Mansehra, Pakistan Safir Ullah Khan Department of Zoology, Hazara University, Mansehra, Pakistan Shakeel Hussain Department of Parasitology, University of Veterinary and Animal Sciences, Lahore, Pakistan Muhammad Javid Department of Zoology, Hazara University, Mansehra, Pakistan Correspondence Inam Ullah Department of Zoology Wild life and Fisheries, University of Agriculture Faisalabad, Punjab, Pakistan Copepod ecto-parasites of Labeo rohita from Dera Ismail Khan, Khyber Pakhtunkhwa Pakistan Inam Ullah, Muhammad Fiaz Khan, Muhammad Seyab Khan, Safir Ullah Khan, Shakeel Hussain and Muhammad Javid Abstract In the present study two hundred rohu (Labeo rohita) form Dera Ismail Khan, Khyber Pakhtunkhwa were examined for ecto parasites, the copepod ectoparasites found were Lernaea cyprinacea, L. arcuata, L. lophiara. Out of 200 fish, 37 were infested (18.5%). In which the predominant parasite was Lernaea cyprinacea. An overall prevalence of ectoparasites was Lernaea. cyprinacea (18.01%), L. arcuata (15.5%). L. lophiara (10.51). Lernaea. Cyprinacea is the most abundant ectoparasite in the overall study. Keywords: Fishes, Copepod, ectoparasites, Labeo rohita 1. Introduction External parasites are the most common parasites encountered in aquatic animals raised in both ponds and aquaria. The major groups of parasites include protozoans, monogeneses and crustaceans [1] . Among crustaceans the copepods which parasitize fish, are the most commonly known pathogenic parasites of cultured fresh water fish in many Asians countries including Pakistan. Their injurious effects on the host are believed to be direct or indirect as their infestation causes formation of lesions and inflammation at the site of attachment which often leads to secondary infections by bacteria [2] . In parasitic copepods, the body segments are often fused. The abdomen has four segments, which are usually all fused in the parasitic species as a result of adaptation to the host. These species are difficult to recognize as arthropods, let alone copepods. Approximately 8,000 species of copepods exist, most of which are free-living. Parasitic infection not only effects the normal growth of fish but also reduce fish population by increasing mortalities. Ecto-parasites attacks to the gills and skin resulting in localized hyperplasia disturb osmoregulation and ultimately kill the host [3] . The incidence and intensity of parasite also varied with season [4] . Young fishes are more prone to infection than old ones [5] . For cultured fish population, the parasites are reported as to involve in the serious outbreak of disease [6] . The crowded culture conditions, temperature and slow water flow increases the parasites multiplication and infestation [7] . Lernaea cyprinacea parasitizes freshwater fish, attaching on the outside surface by boring into the underlying muscle tissues, although the greater part of the parasite body remains outside the host. Heavy infestation by Lernaea is fatal to the host [8] . 2. Methods and Materials 2.1 Study Area District of D. I. Khan bounded on the east by the Bhakkar and Dera Ghazi Khan Districts, of Punjab, to the southwest by South Waziristan, and to the northwest by Tank and Lakki Marwat districts. The district has an area of 7,326 km2 (2,829 sq mt) and a population of 852,995 as per 1998 Census (WWW.GOOGLE.COM). 2.2 Sample Collection Host Fish (Labeo rohita) were collected live from River Indus of Dera Ismail Khan. Fish were collected twelve times during the year (2014-15). 2.3 Examination of specimen A total of 200 fresh water fish, (Labeo rohita) were collected alive from River Indus. The necropsy technique of parasitological examination of skin, fins and gills was carried out for the