Pinning down a polymorphic parasite

New genetic and morphological descriptions of Eimeria macropodis from the Tammar wallaby (Macropus eugenii)

Nichola J. Hill, Carolin Richter, Michelle L. Power*

*Corresponding author for this work

Research output: Contribution to journalArticle

16 Citations (Scopus)


Identification of the protozoan parasite, Eimeria has traditionally relied on oocyst morphology, host range and life-cycle attributes. However, it is increasingly recognized that Eimeria species can vary in size and shape across their host range, an attribute known as 'polymorphism' that presents a unique challenge for identification. Advances in molecular tools hold promise for characterising Eimeria that may otherwise be misclassified based on morphology. Our study used morphologic and molecular traits of the oocyst life stage to identify a polymorphic parasite, Eimeria macropodis in a captive Tammar wallaby (Macropus eugenii) population in Australia. Molecular characterization highlighted the need to use multiple genetic markers (18S SSU and cytochrome c oxidase subunit I) to accurately identify E. macropodis owing to heterozygous alleles at the 18S SSU locus. This study provided an opportunity to assess the utility and shortcomings of morphologic and molecular techniques for 'pinning down' a polymorphic species. Moreover, our study was able to place E. macropodis in an evolutionary context and enhance resolution of the under-studied marsupial clade.

Original languageEnglish
Pages (from-to)461-465
Number of pages5
JournalParasitology International
Issue number3
Publication statusPublished - Sep 2012


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