"So, naturalists observe, a flea has smaller fleas that on him prey; and these have smaller still to bite ’em; and so proceed ad infinitum."
- Jonathan Swift
July 23, 2010
July 23 - Ribeiroia ondatrae
Meet Ribeiroia ondatrae, a nasty and evil (if you ask a tadpole) digenetic trematode. R. ondatrae has quite the complex life cycle requiring three different hosts. Briefly, R. ondatrae uses an aquatic snail as the first intermediate host, tadpoles as the second intermediate hosts and finally, an aquatic bird as the definitive host. R. ondatrae has gained world wide attention as a possible ecological driver behind amphibian declines due to the severe and grotesque limb/body malformations caused by infection, as the cercariae typically encyst as metacercariae within the developing hind limbs of a tadpole. Over the past decade or so, the consequences of this parasite for its tadpole intermediate host have been intensively investigated, especially in the context of additional stressors such as environmental contaminates. However, much more work is required in order to determine the specific mechanisms behind how this parasite actually messes up normal limb patterning and development.
Contributed by Dorina Szuroczki.