Oesophagotrema mediterranea n. gen., n. sp. (Platyhelminthes, Digenea, Zoogonidae), parasite of the needlefish Tylosurus acus imperialis (Beloniformes, Belonidae) from off Tunisia

Oesophagotrema mediterranea n. gen., n. sp. (Digenea, Zoogonidae) is described from the needlefish Tylosurus acus imperialis (Beloniformes, Belonidae) off the Tunisian coast. Oesophagotrema n. gen. is distinguished from all other Lepidophyllinae genera by the combination of a prominent rounded ventral sucker, caeca reaching to the anterior edge of the posterior testis, testes arranged in tandem in the middle third of the hindbody and the vitellarium in symmetrical lateral bunches located between the ovary and anterior testis. This species shows a typical specific site of infection within the digestive tract, i.e., the oesophagus and vomer teeth. The position of this zoogonid digenean on the oesophagus is discussed.