"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

March 12, 2010

March 12 – Lepidapedon sp.

Here’s Lepidapedon, a lepocreadiid digenean. Lepocreadiids are very common in marine fishes and are almost a prototypical digenean; they have oral and ventral suckers, two testes (the big medial blue blobs), one ovary (darker blue blob in front), a lot of cortical vitelline follicles for making egg shells (the brown blobs all round the outside) and a lightly spiny tegument, which probably aids them in holding onto the intestinal mucosa of their teleost fish hosts. Like all digeneans, they have complex life cycles involving a mollusk first intermediate host, but in most cases, including this one, that host is not known. After the mollusk comes a crustacean of some sort, again unknown in this case, which is actively penetrated by the cercarial stage that emerges from the mollusk. The definitive fish host becomes infected by eating the crustacean. This Lepidapedon is from the intestine of the butterfish, Peprilus triacanthus, a common midwater schooling fish on the Atlantic coast.

Contributed by Al Dove.

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