* Oval and flat body

* Range in length from 1.5 millimeters to 35 millimeters

* Well adapted to aquatic environment

* Hind pair of legs is long, flattened, and fringed to provide surface area that aids in flotation

* The spiracles (openings through which the beetle breathes) are on the abdomen just under the tips of the wing covers

* In a resting position--below the water surface on an incline with the head down--the beetle raises the tips of the elytra and breathes through the spiracles

*When ready to dive, it stores a supply of air under its wings for breathing while under water

* Predacious diving beetles are carnivorous, preying on insects and other aquatic organisms, including fish larger than they.

*The female deposits eggs in the water or on aquatic vegetation; the larvae, known as water tigers because of their voracious appetite, are long and slender and have sickle-shaped jaws.