Aptorchis glandularis n. sp. (Digenea: Plagiorchioidea) from the northwestern red-faced turtle, Emydura australis, (Pleurodira: Chelidae) in the Kimberley, Western Australia.

Aptorchis glandularis n. sp. is described from the intestine of the northwestern red-faced turtle, Emydura australis (Pleurodira: Chelidae), in the Kimberley, Western Australia. This digenean is morphologically most similar to Aptorchis aequalis but can be differentiated readily from the latter species by the presence of ventral glands arranged in 3 rows. This feature is unique among plagiorhioidean digeneans and resembles the glands observed in some monostome digeneans in Notocotylidae and Microscaphidiidae. Comparison of approximately 2,600 bases of ribosomal DNA (partial 18S, complete ITS1+5.8S+ITS2, partial 28S), obtained from all 5 known Aptorchis species, strongly supports the status of Aptorchis glandularis n. sp. as a new species. Phylogenetic analysis of these sequence data demonstrates 2 strongly supported clades (A. pearsoni + A. megacetabulus) and (A. aequalis + A. glandularis n. sp.), with A. megapharynx representing a separate lineage. This is the first report of an endoparasite from Emydura australis.