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United States Department of Agriculture

Agricultural Research Service

Research Project: PARASITIC BIODIVERSITY AND THE U.S. NATIONAL PARASITE COLLECTION

Location: Animal Parasitic Diseases

Title: Critical Comment: On the morphology and taxonomy of Griphoibilharizia amoena Platt and Blair, 1991 (Schistosomatoidea), a dioecious digenetic trematode parasite of the freshwater crocodile, Crocodylus johnstoni, in Australia

Authors
item Platt, Tom -
item Hoberg, Eric
item Chisholm, Leslie -

Submitted to: Journal of Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 1, 2013
Publication Date: October 18, 2013
Citation: Platt, T., Hoberg, E.P., Chisholm, L. 2013. Critical Comment: On the morphology and taxonomy of Griphoibilharizia amoena Platt and Blair, 1991 (Schistosomatoidea), a dioecious digenetic trematode parasite of the freshwater crocodile, Crocodylus johnstoni, in Australia. Journal of Parasitology. 99:888-891.

Interpretive Summary: Correct interpretations of morphology (structural characters) are at the foundations for understanding the origins and evolution of different organisms and how they are related. Comparative morphology and its interpretation are consequently significant underpinnings for a taxonomy that reflects relationship and connectivity in the biosphere. In this regard, among the blood flukes (flatworm parasites of the circulatory system of vertebrates), Griphobilharzia amoena was originally described as a dioecious trematode (separate sexes) parasitic in the circulatory system of the Australian freshwater crocodile, Crocodylus johnsoni, with the female completely enclosed in a chamber of the male and the 2 worms oriented anti-parallel. A recent publication called into question the original description arguing G. amoena is monoecious (single worm containing male and female organs) and was transferred to a different genus, Vasotrema (Spirorchiidae). We reexamined the type specimens held in US National Parasite Collection and in Australia and provide convincing evidence that the original description of G. amoena is correct in all important respects and that the genus Griphobilharzia should be recognized as valid containing a single species, Griphobilharzia amoena. Definition of the correct anatomy of G. amoena is not trivial and has implications for understanding the complex origins and evolution of the dioecious condition within the Schistosomatoidea (the superfamily of blood flukes). This information is critical for parasitologists working on the evolution of blood flukes which remain among the most significant of pathogens for humans in tropical and subtropical regions. Further this work validates the correct taxonomy for specimens of these parasites that constitute the type series held in museum repositories in North America and Australia, contributing to authoritative identifications of these and other parasitic flukes.

Technical Abstract: Griphobilharzia amoena Platt and Blair, 1991, was originally described as a dioecious trematode parasitic in the circulatory system of the Australian freshwater crocodile, Crocodylus johnsoni, with the female completely enclosed in a gynecophoric chamber of the male and the 2 worms oriented anti-parallel to each other. A recent publication called into question the original description arguing G. amoena is monoecious and was transferred to Vasotrema Stunkard, 1928 (Spirorchiidae) as V. amoena n. comb. We provide convincing photomicrographic evidence that the original description of G. amoena is correct in all important respects and the genus Griphobilharzia Platt and Blair, 1991, should be recognized as valid containing a single species, Griphobilharzia amoena Platt and Blair, 1991. Definition of the correct anatomy of G. amoena is not trivial and has implications for understanding the complex origins and evolution of the dioecious condition within the Schistosomatoidea.

Last Modified: 10/25/2014
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