"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

February 19, 2010

February 19 - Pterygodermatites peromysci

Pterygodermatites peromysci is a common intestinal nematode of Peromyscus leucopus, the white-footed mouse and Peromyscus maniculatus, the deer mouse. P. peromysci inhabits the small intestines of these two rodents where it lives out its days feeding on the nutrients taken in by the mouse. The life cycle of this parasite is complex and requires passage through an intermediate host Ceuthophilus pallidipes, the camel cricket. Eggs are shed in the mouse faeces and ingested by the cricket. The nematode develops inside of the crickets hemocoel, or body cavity where it floats around encysted inside gut epithelium until a hungry mouse gobbles up the tasty cricket treat, continuing the parasites life cycle. The parasite in the photo was isolated from Peromyscus maniculatus captured in the Great Basin desert in Utah.

Contributed by Craig Gritzen.


  1. Susan, I would try to say the name, but need the phonetic transcription. Please consider adding it for us non-parasitologists. Thank you!

  2. I hate to attempt this -I'm not a phonetic person, but it would kind of be like this (written with common words or word-like things).

    terry-go-der-ma-tighties pair-oh-misk-eye

  3. Thank you! It sounds good to me.