A new rhabdochonid species (Nematoda: Rhabdochonidae) parasitizing Cyprinion watsoni (Cyprinidae) in Pakistan

During a survey for parasitic helminth fauna of freshwater fishes,a new species of rhabdochonid nematode rhabdochona (rhabdochona) bifurcatum n. sp. is described parasitizing the intestine of the fish host cyprinion watsoni (day,1872) capture in the valley of district bolan. the new nematode specimens differ in several diagnostic features compared with previously known species of the genus rhabdochona railliet,1916. unique to the new species is the presence of small spicule which is anteriorly bifurcated in to two unequal arms pointed at the tip. the present species is also characterized by having 8 prostomal teeth,9 pairs of caudal papillae including 4 preanal and 5 postanal in males and eggs devoid of filaments or lateral floats in females. excretory pore of both the sexes is postequatorial. copyright 2012 zoological society of pakistan.