The question has come up on ScienceBlogs as to which class of invertebrates are the best, coolest, etc. Like PZ I had though about saying Cephalopods (because of those nice octopi that helped the archaeology community find some pottery), but in the end I had to go with Arthropods. Let me give you a few examples as to why.
First, they come in both marine and terrestrial varieties. When was the last time you saw a mollusk on land (the ones at Red Lobster being slurped down by primates don’t count)? Terrestrial Cephalopods? Terrestrial Echinoderms? Feh! Never happens!
Let me introduce you to some wickedly cool arthropods. Meet Paracerceis sculpta
P. sculpta is an interesting little marine arthropod. Pictured above is the female and three male morphs. The &alpha – morph (the largest of the three) breeds by gathering a harem of females, which take residence in sponges. The &beta – morph mimics the female morphology and tricks the &alpha – morph into thinking it is a female. When the &alpha – morph isn’t looking, the &beta morph mates with the females. Pretty tricky, no? It gets better. The &gamma – morphs, and this is where things get wickedly cool, is much smaller and more agile than the &alpha – morph and simply out maneuver the &alpha morph to obtain access to females. No big deal you say. Well, there is good evidence that some of the &gamma – morphs are actually genetically female and have changed their sex to maximize their reproductive fitness.
Still not convinced?
Okay, meet the spiders of the genus Portia. Members of this genus prey on web-building spiders using some interesting trial and error tactics. When they are on a spider web they send out a wide variety of vibratory signals – modifying them based on the movements of the prey spider. Basically, they use trial and error to obtain their goals. The also take advantage things like vibration caused by the wind to move closer to their prey (in effect they use wind vibration to camouflage their movements).
Still not convinced? You are a tough crowd, but okay. How about beetles? I’m not talking any beetle here, but those, such as the leaf beetles, the Opilionid beetles, and of course the Bombardier beetle. I’m talking bad ass beetles that lay a toxic chemical smackdown on anyone or anything insane enough to mess with them. Want to be on the business end of this:
I rest my case.