Plectanocotyle major sp. n. (Monogenea: Plectanocotylidae), a gill parasite of Chelidonichthys obscurus (Teleostei: Triglidae) from the Mediterranean Sea.

Plectanocotyle major sp. n. (Monogenea: Polyopisthocotylea: Plectanocotylidae) is described from Chelidonichthys obscurus (Bloch et Schneider, 1801) collected from the Mediterranean coasts (Tunisia and France). The new species is compared to Plectanocotyle gurnardi collected on Chelidonichthys gurnardus and the only other valid species in the genus Plectanocotyle. The new species differs from P. gurnardi by the clamp size (137 microm vs 64 microm for clamp length and 110 microm vs 60 microm for clamp width, respectively) and the length of the male copulatory organ (107 microm vs 144 microm, respectively). Species of the Plectanocotylidae seem to be characterized by an oioxenic specificity.