"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
January 15, 2010
January 15 - Curtuteria australis
Curtuteria australis Allison 1979 (Platyhelimthes: Digenea: Echinostomatidae) infects bivalves (in this case, a cockle, a type of clam) on the mudflats and sandflats of New Zealand. This parasite lodges itself in the foot of the bivalves where it forms a hard cyst. As more and more parasites accumulate, the cockle loses its ability to dig itself into the underlying sediment, leaving it stranded on the surface of the mudflat/sandflat. There, it is exposed to predation by shorebirds such as oystercatchers, which are the parasites' next hosts. These parasites also have a cascading effect on the rest of the ecosystem - as the mudflat is filled with stranded bivalves, the nature of the substrate changes from one consisting largely of mud and sand, to one littered with the hard shells of bivalves. This, in turn, alters the biotic community which inhabits the rest of the ecosystem.
The photo shows a cockle's foot with encysted metacercariae of Curtuteria australis tagged with a fluorescent dye.
Contributed by Tommy Leung.
Read the full paper here.