Integration of morphological and molecular data reveals further unknown diversity of the Proterodiplostomidae in crocodilians

Abstract

The Proterodiplostomidae Dubois, 1936 is a family of digeneans within the superfamily Diplostomoidea Poirier, 1886. Members of the family are distributed mostly in the tropics and subtropics, primarily in crocodilians, although some species are known from other reptiles. Despite their broad geographic distribution, the knowledge of proterodiplostomid diversity remains limited, mostly because a number of potential host species and regions of the world have not been sufficiently explored for these parasites. In this study, we use morphological and molecular data to describe four new genera (Afroproterodiplostomum gen. nov., Dungalabatrema gen. nov., Australiadiplostomum gen. nov. and Nattererodiplostomum gen. nov.) and five new species (Afroproterodiplostomum ingwenyae sp. nov., Australiadiplostomum blairi sp. nov., Dungalabatrema kostadinovae sp. nov., Dungalabatrema snyderi sp. nov. and Pseudoneodiplostomum angustus sp. nov.) of proterodiplostomids from crocodilians in Australia, South Africa and South America. Nattererodiplostomum gen. nov. has been established upon re-evaluation of the status of Proterodiplostomum medusae (Dubois, 1936) from caimans in Brazil using combined morphological and molecular evidence. Only a few previous studies provided DNA sequence data of proterodiplostomids. We generated partial 28S rDNA and cytochrome c subunit (cox1) mtDNA sequences for three previously undescribed proterodiplostomids collected from Crocodylus spp. in Australia and South Africa. The newly generated 28S sequences were used to examine phylogenetic affinities of these taxa. All three newly sequenced proterodiplostomid species appeared in the phylogenetic tree in a strongly supported monophyletic clade comprising exclusively parasites of Crocodylus.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:C30F977D-4A0B-4D8C-8BAF-0D6C48B5396B

Key Words:

• Africa
• Australia
• crocodilians
• Diplostomoidea
• Proterodiplostomidae
• South America

Acknowledgements

We thank Dr Scott Snyder for organizing and assisting with the collection of helminths from Australian freshwater crocodiles. We are grateful to Dr Danny Govender (SANParks, South Africa), Prof. Joop Boomker (University of Pretoria, South Africa) as well as Mr Frans R. Masubelle and Mr Daniel M. Chipana (ARC-Onderstepoort Veterinary Institute, South Africa) for facilitating and assisting in parasite collections from Nile crocodiles.

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Associate Editor: Dr Peter D. Olson

Additional information

Funding

This work was supported by the National Science Foundation (grant number DEB-0515492), (grant number DEB-1120734) for VVT. TJA was supported by the University of North Dakota (Joe K. Neel Memorial Award, Esther Wadsworth Hall Wheeler Award, Student Research Stipend and Summer Doctoral Fellowship) and Annual Midwestern Conference of Parasitologists (AMCOP Student Research Grant). TPC was supported by the National Institute of General Medical Sciences of the National Institutes of Health (Institutional Development Award (IDeA) grant number P20GM103442) to the University of North Dakota School of Medicine & Health Sciences. Examination of proterodiplostomid specimens deposited in the collections of the Natural History Museum, London, received support from the SYNTHESYS + Project http://www.synthesys.info/ financed by European Community Research Infrastructure Action under the H2020 Integrating Activities Programme, Project number 823827, to VVT.