Ever since the wonderful article on how to find Tardigrades in your backyard, I have been doing my bit to find them in local lichens and as it usually happens, I am completely drawn away by other life forms I see in the same space: the complex of fungi and chlorophytes in an intimate association, ciliates at times and even an insect or two. While I haven’t found a Tardigrade in this hunt yet, I was quite pleased with a nematode that revived itself from its dauer/cryptic state to dance away under the foldscope. Several anatomical aspects are quite clear in the first video, although I think a still nematode and some stains might have revealed more. I think this is a rhabditiform related to C. elegans, but nematodes can be very diverse with the same body plan. In fact, ever since the genome of C. elegans was published their relationship to other animals has always been a matter of some debate (the ecdysozoa vs coelomata hypotheses). Part of the problem is that many proteins of the nematode are fast evolving giving long branches in phylogenetic trees and artificial groupings. Some feel that the worm state is only a degeneration from a more complex morphology.
Nematodes are perhaps as diverse as insects, and some even estimate that this is the largest group of animals. They are extremely hardy, found in all kind of environs and numerous. I remember reading about a survey around the Dutch coast where they found 4 million nematodes per square meter. A large number of them are also parasitic, and some cause deadly diseases in humans such as elephantiasis-filariasis, ascariasis, Loa Loa filariasis, Dracanculiasis and so on. This one though is definitely not parasitic :-), but it danced on my table and walls as you shall see below.
First a compilation of various videos of the nematode.
Video 1: Compilation of nematode videos
At this point, the kids wanted some entertainment and so we decided to project the moving nematode through our cardboard setup and what a scary movie it was!
Video 2: Scary movie (Warning use your discretion :))