New gnathiid isopod crustaceans (Cymothoida) from Heron Island and Wistari Reef, southern Great Barrier Reef.

Eleven species including six new species of Gnathiidae (Crustacea, Isopoda, Cymothoida) are reported from the Heron Island and Wistari Reef, Capricorn Group, southern Great Barrier Reef: Elaphognathia queenslandica sp. nov., Gnathia acrorudus sp. nov., Gnathia capricornica sp. nov., Gnathia carinodenta sp. nov., Gnathia formosa sp. nov. and Gnathia glaucostega sp. nov. Gnathia cornuta Holdich Harrison, 1980 and Gnathia grutterae Ferreira, Smit Davies, 2010 are for the first time reported from Heron Island and new records from Heron Island are provided for Gnathia biorbis Holdich Harrison, 1980, Gnathia variobranchia Holdich Harrison, 1980, and Gnathia wistari Svavarsson Bruce, 2012.