Freshwater Ecology 1: Back to the Basics

It's been a while since I've updated. Between two weddings, a funeral, and academic concerns my time has been in high demand; though I've managed to carve out a little time for myself here and there I've been so exhausted that any productive work with Nereus seemed like a chore. With any luck I'll be able to get into a routine with my personal life and can devote more consistent effort to Nereus.

The two latest species are the first of the group representing freshwater life. Because they represent the foundation of an ecosystem, they are quite simple species, relatively speaking. Also, because they are such primitive nereids it meant I had to revisit clades that have escaped my attention for some time. I'm discovering what a shambles much of my project is in, and will probably do some taxonomic reorganization once I finish this group.

The pearl worm is a very primitive life form, which means it provided familiar challenges for me but at a somewhat amplified level. First off, I wanted to make sure it fit within the evolutionary framework of the planet, and because it's phylogeny is so very different from every other wormlike species I've done so far it required a whole new taxonomic class. I basically had to build this creature from scratch, making sure that not only did it work as a species on its own but that it had a place in evolution; you be the judge of whether I was successful or not. Also, since I don't like to have a whole class with only one example if I can help it, this means I should probably come up with a few close cousins for this guy.

Secondly, I wanted to make sure it was in fact primitive. While I understand the appeal of superpredators and monsters of prehistoric proportions, I really appreciate seeing some of the more basic species as well. To me, it shows just how in-depth the project really is and helps me see the "big picture" of the world. I like to show that same attention to detail in my own work, and I hope I've done so with the pearl worm.

Finally, and as I've said before, I always want my nereids to be interesting. Making a worm-like critter that has little visual or conceptual difference from an earthworm just doesn't seem worth my time. The swelling yellow tissue was something I thought would really make the pearl worm iconic, and figuring out how it serves the creature that much more fun. I hope it's fun for you too.

The other species I'll talk about here is the river limpet. I must confess a common mistake of mine: that of confusing a limpet with a chiton. I don't know why I always mix the two up, but as a result you may notice that the river limpet has some chiton-like traits. Luckily, when working with aliens I can make such "mistakes," blending traits from different species to make a single unique creature. I considered changing the name to "river chiton," but it didn't seem to have the same ring. Instead I added some physical traits from the limpet to make it so that fictional xenobiologists can make the choice.

At the same time, of course, the river limpet must be uniquely nereid in nature. It has inherited the nested shells, limbs, and motipalps from mollipod ancestors, and while all have specialized, duplicated, and/or atrophied, its heritage should be apparent. I decided to show this species from the underside not only to show how the limbs function as mouthparts in this clade, but I'd never shown the underneath of a mollipod and I thought it would reveal a lot about their phylogeny to do so. Have fun seeing a little critter's underbelly!