E is for Elmid Beetle.

There are more species of beetles than any other insect on the planet. If beetles were a phylum, they would be the largest phylum on the planet, as well. To find a grouping larger than the beetle, one would have to look at kingdoms. Most beetles are terestrial, land dwelling, but some are aquatic. The Elmid beetle is one of many aquatic beetles. The Elmid beetle would not be found in the great Colorado River, but instead in still water ponds. This beetle lives among the stones and rocks one would find along the bottom of a pond. The Elmid Beetle can stay under water for a long period of time because it carries an air bubble with it. The beetle must periodically come to the surface to refill the air bubble.