Many micro-metazoans are affected by endoparasitic life forms in their guts. Especially polychaetic and oligochaetic worms are preferred hosts for endoparasites. Therefore the thorougly investigation of the gut of worms reveals sometimes surprising findings.
About 2 months ago I found the strange endoparasitic relationship of a metazoan within a metazoan. In this case the host is the oligochaetic worm Nais elinguis (very common in Simmelried) while the endoparasite is the rotifer Albertia naidis. At first glance with lower magnification the specimen of N. elinguis appears healthy. But at higher magnification moving, worm-like individuals within the gut of N. elinguis become visible. To have a closer look it is necessary to reduce the layer thickness beneath the coverslip to fix the movement of the host. Now the 120 – 165 µm long parasitic rotifer A. naidis can be investigated in detail. The mastax (MA) is shaped like a tweezer to pick up pieces of the endothel cells of the gut and for fixing at the inner gut wall to keep the position within the gut. Because it has not to swim the corona is strongly reduced. The alimentary system of A. naidis is reduced too. No eyespot recognizable. Sometimes in the posterior end of Albertia big eggs can be find. Many of them will be flushed out for ingestion by the next host. I have found A. naidis three times. In all cases the host was affected by 2-6 specimens Albertia. The infection rate of N. elinguis from the Simmelried with A. naidis is 1-5 % according my observations.
Beside the images shown below I could take a little video of Albertia naidis in Nais elinguis. Enjoy it!
Martin
The video:
http://www.lifecells.de/Forum/Albertianaidis-090808.wmv
The images:
). Now, with your images and footage that sentence in KAESTNER really comes alive! I think I won´t forget the endoparasitic rotifers from now on.