Monster...a closer look

I blew up some sections of a photo Cailyn and I took of a hellgrammite we seined out of a local creek yesterday. They are really amazing creatures if you can get past the scary part and take a closer look. But make no mistake they are miniature monsters. For instance take a look at this pic of its mandibles.  

Those pincers or mandibles are what entomologists (people who study insects) call heavily sclerotized. Sclerotization is a process cross-linking the various protein molecules with phenolic compounds which means that the normally very hard exoskeleton of the insect becomes even harder, turning the hellgrammites "iron" into "steel". The hellgrammite uses these pincers kill just about anything it can get a hold of, things like aquatic insects , tiny fish and  amphibians, or any small invertebrate that is a bottom dweller. And pinch the heck out of your fingers if your not careful. Yeah those pincers are short compared to adult hellgrmmites (called dobsonflies) or those of some beatles but those guys are just for show and fighting for a mate, while the hellgrammites are for killing and are very powerful. The next picture shows the other end of our hellgrammite. 

It has two anal prolegs and on the end of each is a pair of stout hooks that the hellgrammite uses to help anchor itself in swift current and not be swept away. More on that in just a bit. In the next photo we can see some of the eight pointy prolegs that like the abdominal section of the hellgrammite and the fuzzy gills at their bases.  

The feathery looking gills sticking off the sides are rather immobile and simply increase the surface area. The other set of gills, the puffy dandelion fluff looking ones, have muscles attached to them. When a hellgrammite become oxygen stressed, it can wave those gills around through the water. Considering the adaptations hellgrammites display and the swift riffles they live in, hellgrammites need a lot of oxygen to survive. That’s where the hooks and the gills come in: they both help the hellgrammite get as much oxygen from the water as possible.

Heres a great video I found on Youtube that shows all this stuff in action...