Description of a New Genus and Species of Cyathocotylid Digeneans from Australia.

PURPOSE: Cyathocotylidae Mühling, 1896 is a cosmopolitan family of diplostomoidean digeneans characterized by a broad range of vertebrate definitive hosts, including fishes, birds, reptiles, and mammals. Cyathocotylid diversity in Australasia remains poorly known. In the present study, we describe a new genus and species of cyathocotylid digenean collected from the small intestine of the Australasian gannet, Morus serrator, in Queensland, Australia.

METHODS

Adult cyathocotylid specimens were collected from the small intestine of an Australasian gannet in Queensland. Specimens were stained, mounted, and examined using DIC microscopy. Genomic DNA was extracted, and a fragment of the large ribosomal subunit (28S) rDNA was sequenced and compared with available sequences from cyathocotylids.

RESULTS

A new genus and species, Glandocirrus crikey n. gen., n. sp., is described. It can be readily distinguished from all other cyathocotylid genera by its exceptionally large, strongly glandular cirrus sac. The 28S sequence is identical to previously published unidentified cercariae from Australia, thereby linking larval and adult stages and confirming the distinctiveness of the lineage.

CONCLUSIONS

This discovery represents the seventeenth genus of Cyathocotylidae and only the second from Australasia supported by DNA data, emphasizing the underexplored diversity of diplostomoideans in the region.