A new macradeninine, Zebrasomatrema pichelinae n. g., n. sp. (Digenea: Lecithasteridae), from tangs (Perciformes: Acanthuridae) off the southern Great Barrier Reef, Queensland, Australia.

A new genus, Zebrasomatrema, with the type-species Z. pichelinae n. sp., is described from Zebrasoma veliferum at Heron and Lizard Islands, Queensland, Australia, and Z. scopas, Acanthurus lineatus and A. triostegus at Heron Island. The new genus shares with Acanthurotrema an anterior flange, 14 subglobular vitelline lobes, a divided seminal vesicle and a long aglandular duct joining the seminal vesicle and the short pars prostatica, but differs in its quadripartite seminal vesicle, single vitelline field, lack of a sinus-sac and excretory arms which unite in the forebody. This report constitutes the first record of a macradeninine lecithasterid in Australian waters. A key to the Macradenininae is presented.