Using combined morphological, allometric and molecular approaches to identify species of the genus Raillietiella (Pentastomida)

Crystal Kelehear*, David M. Spratt, Sylvain Dubey, Gregory P. Brown, Richard Shine

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

43 Citations (Scopus)
6 Downloads (Pure)


Taxonomic studies of parasites can be severely compromised if the host species affects parasite morphology; an uncritical analysis might recognize multiple taxa simply because of phenotypically plastic responses of parasite morphology to host physiology. Pentastomids of the genus Raillietiella are endoparasitic crustaceans primarily infecting the respiratory system of carnivorous reptiles, but also recorded from bufonid anurans. The delineation of pentastomids at the generic level is clear, but the taxonomic status of many species is not. We collected raillietiellids from lungs of the invasive cane toad (Rhinella marina), the invasive Asian house gecko (Hemidactylus frenatus), and a native tree frog (Litoria caerulea) in tropical Australia, and employed a combination of genetic analyses, and traditional and novel morphological methods to clarify their identity. Conventional analyses of parasite morphology (which focus on raw values of morphological traits) revealed two discrete clusters in terms of pentastome hook size, implying two different species of pentastomes: one from toads and a tree frog (Raillietiella indica) and another from lizards (Raillietiella frenatus). However, these clusters disappeared in allometric analyses that took pentastome body size into account, suggesting that only a single pentastome taxon may be involved. Our molecular data revealed no genetic differences between parasites in toads versus lizards, confirming that there was only one species: R. frenatus. This pentastome (previously known only from lizards) clearly is also capable of maturing in anurans. Our analyses show that the morphological features used in pentastomid taxonomy change as the parasite transitions through developmental stages in the definitive host. To facilitate valid descriptions of new species of pentastomes, future taxonomic work should include both morphological measurements (incorporating quantitative measures of body size and hook bluntness) and molecular data.

Original languageEnglish
Article numbere24936
Pages (from-to)1-10
Number of pages10
JournalPLoS ONE
Issue number9
Publication statusPublished - 20 Sept 2011
Externally publishedYes

Bibliographical note

Copyright the Author(s) 2011. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.


Dive into the research topics of 'Using combined morphological, allometric and molecular approaches to identify species of the genus Raillietiella (Pentastomida)'. Together they form a unique fingerprint.

Cite this