"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.