"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 18, 2010

February 18 - Gigantolina elongata

Gigantolina elongata belongs to a small group (as in only 8 species are known!) of parasitic worms known as amphilinids. Although some of these parasites infect fish, this species is found in freshwater turtles of Australia. The parasites are bright yellow in color and as many as 30 of the large (150+ mm) worms can be found in a single host. It is unclear exactly how the eggs of the worm are released in the water, but once they do, larvae hatch out and find a young crayfish where they penetrate the cuticle of their host by a complex process that involves both chemical digestion of the cuticle and sawing it open with tiny hooks. When turtles eat the crayfish, the young worms pentrate the turtle’s esophagus and make their way to the body cavity where they will grow and mature into adults.

Nominated by Klaus Rhode


  1. Very Cool. I followed the link to the tol website and was hoping to find some info on higher level phylogenies, but there wasn't much info there. Is it known where they lie within the Metazoa? Is anything known about their embryological development? Is there a prototroch, for instance?
    Facinating stuff. Just when I think I have heard of all the Phyla.....

  2. They are currently placed in the class Cestoda, though distinct from the eucestoda, the more familiar tapeworms.