Opecoelidae (Digenea) in northern great barrier reef goatfishes (Perciformes: Mullidae).

The Opecoelidae (Digenea) of eight species of goatfishes (Perciformes: Mullidae) were studied off Lizard Island on the northern Great Barrier Reef (GBR). Host species included Mulloidichthys flavolineatus (Lacépède), M. vanicolensis (Valenciennes), Parupeneus barberinus (Lacépède), P. ciliatus (Lacépède), P. cyclostomus (Lacépède), P. indicus (Shaw), P. multifasciatus (Quoy & Gaimard), P. spilurus (Bleeker) and P. trifasciatus (Lacépède). Seven opecoelid species were found, of which Paropecoelus corneliae n. sp., Pa. leonae n. sp. and Pseudopecoeloides engeleri n. sp. are described as new. Paropecoelus elongatus (Ozaki, 1928), Pa. sogandaresi Pritchard, 1966 and Podocotyloides parupenei (Manter, 1963) are recorded and a description is provided for each. A second species of Pseudopecoeloides remains unnamed for want of sufficient morphological material. The seven species were distinguished on the basis of morphology and molecular analysis of 56 ITS2 rDNA sequences. Sequences differed by nine to 68 base pairs between species combinations recognised by morphology; no intraspecific variation was detected. Each opecoelid species infected between two and five mullid species, but none of the species has been found in non-mullid hosts. Every mullid species was infected with at least one species of opecoelid and Parupeneus ciliatus had all seven species. The Opecoelidae of GBR goatfishes are consistent with the typical pattern of stenoxenicity seen for trematodes of GBR fishes.