ABSTRACT

A new trematode Parapolylekithum karachiensis n. gen, n. sp. from the intestine of the fish Cybium guttatum of Karachi coast has been described. The trematode is characterized by having small body without spines that is 1.3-1.5 by 0.37-0.38 in size. It has oral and ventral suckers almost equal in size, a relatively long pre-pharynx, a small poorly developed pharynx, a long esophagus, and ceca not reaching to posterior end of the body that terminate posterior to the posterior testis. The acetabulum is preequatorial. The testes are tandem in the posterior third of the hind body. The cirrus pouch is relatively large extending far behind the acetabulum, enclosing a rounded seminal vesicle, a prostatic complex and long cirrus with a tuft of hairs at the bottom. The genital pore is anterolateral to the acetabulum and the prominent genital atrium is surrounded by numerous gland cells. The ovary is median, posterior to acetabulum, before the testicles, and a seminal receptacle is present. Vitelline follicles extend from nearly the posterior end to the post-acetabular region. The uterus is between the ovary and acetabulum. Eggs are large, operculated and 0.056- 0.058 mm by 0.035-0.036 mm in size.

Keywords: Parapolylekithum karachiensis, Allocreadiidae, Cybium guttatum, Karachi coast