Abstract
A new hemiurid trematode Prosorchis macroacetabulum is described here from the fish Stromateus niger (Bl) collected from the fish
harbour, Karachi coast, Pakistan. Body of this fluke is dorsoventrally flattened, wide. Oral sucker is subterminal, prepharynx absent,
pharynx comparatively small, esophagus indistinct, ceca wide projecting anteriorly towards oral sucker and reaching to the posterior
end of the body. Acetabulum more than three times larger than oral sucker, almost equatorial. Testes two, preacetabular, seminal
vesicle anterior to testes, slightly twisted, pars prostatica small, well differentiated, hermaphroditic duct is also small, genital pore
ventral to posterior border of pharynx. Ovary is postacetabular and postequatorial, receptaculum seminis small, vitellaria composed of
seven, long, convoluted tubules, uterus reaching to near about posterior region of the body, joining hermaphroditic duct anteriorly at
the level of cecal bifurcation, eggs numerous, small, excretory vesicle is Y-shaped.
