Abstract
Two new trematodes of genus Tubulovesicula (Hemiuridae: Dinurinae) are described here from the stomach of the fish
Plectorhynchus cinctus (T.S.) of Karachi coast, namely Tubulovesicula microrchis n.sp., and Tubulovesicula magnavesicula n.sp. T.
microrchis is characterized by having elongate body, short ecsoma, oral cucker small, wider than long, prepharynx and esophagus
absent, caeca long reaching to posterior extremity of ecsoma. Acetabulum larger than oral sucker, round, in anterior third of body
proper. Testes two, ovary small, between acetabulum and ovary, separate, oblique. Seminal vesicle long. Tubular, slightly twisted,
reaching far posterior to acetabulum, pars prostatica large, mostly preacetabular, hermaphroditic duct enclosed in a pouch. Genital
pore posteroventral to pharynx. Ovary post-testicular, oblong, in anterior half of body proper. Vitellaria consist of long winding, thick
tubules, laterally overlapping caeca reaching to body margins, far anterior from end of body proper, uterus winding reach posteriorly
to a little distance but not entering into ecsoma, then ascending anteriorly between the two testes to the preacetabular region. Another
species T. macrovesicula n.sp. also has elongate body with ecsoma more than half of body proper in length. Oral sucker cup-shaped,
subterminal, prepharynx and esophagus absent. Caeca long reaching to posterior extremity of ecsoma. Acetabulum large, rounded, in
anterior half of body proper. Genital opening at the base of pharynx. Testes two, postequatorial, obliquely symmetrical, seminal
vesicle large, mostly postacetabular reaching to the anterior and close to posterior testis, pars prostatica preacetabuar, hermaphroditic
duct long, preacetabular, hermaphroditic pouch prominent. Ovary rounded to oval, near posterior end of body proper, vitellaria consist
of 6-7 long, twisted tubules, two small, directed anteriorly, 4-5 directed posteriorly reaching into tail. Uterus coiled entering to a long
distance into ecsoma.
