TETROCHETUS BALOCHISTANENSIS N.SP. (DIGENEA: ACCACOELIIDAE) FROM DOLPHIN FISH CORYPHAENA HIPPURUS (PERCIFORMES: CORYPHAENIDAE) OF GWADAR COAST, BALOCHISTAN, PAKISTAN.

Abstract

Thirty dolphin fish Coryphaena hippurus Linnaeus, 1758 (Perciformes: Coryphaenidae) were collected from the Gwadar Coast, Balochistan. Four hosts were found positive with trematodes of genus Tetrochetus Looss, 1912. Present specimen differs from its congeners in having a smaller body, muscular and robust body; both the oral sucker and ventral suckers have same size, oral sucker terminal; testes oval-shaped, pre-ovarian and laterally positioned in middle of the body; median, oval-shaped ovary located near hind testis; vitelline glands tubular, compact, extending from anterior border of ovary up to mid-level of ventral sucker. On the basis of these varying characters between present species and its congeners, a new species Tetrochetus balochistanensis proposed. However, this genus is the first host recorded from Balochistan, Pakistan.