Abstract
A new trematode belonging to the genus Bucephalus Baer, 1926 is described here from the intestine of the fish Pomadasys olivaceus of Karachi coast. The new species Bucephalus hexalobatus is characterized by having body slender anteriorly, broader behind and tapering to a rounded posterior end. Rhynchus is weakly muscular with 6 lobed at anterior extremity, mouth opening is post equatorial, testes oval to rounded in posterior half of the body, obliquely tandem, anterior testis large, immediately pot ovarian, posterior testis dorsal to cirrus pouch. Cirrus pouch is cylindrical and confined to posterior third of the body, seminal vesicle elongate, pars prostatica well developed, genital lobe occupying the genital atrium, genital pore ventral, close to posterior extremity. Ovary is ovoid, pretesticular, close to anterior testis. Vitelline follicles are relatively large, centrally located anteriorly, nearer to rhynchus, 26- 28 in number, in the anterior third of the body, these are 0.71-0.82 mm from anterior extremity. Uterus is extensive reaching to almost posterior half of vitelline field and occupying almost all available space posterior to vitellaria. Eggs are numerous, small, 0.020-0.024 by 0.017-0.019 in size. Excretory vesicle not prominent but appears to extend anterior to vitellaria.
