A Closer Look

This slide show introduces some of the benthic macroinvertebrates* found in our Potomac Highland streams. Many of these organisms are the aquatic larvae of insects that will leave the water as flying adults for only a brief time - often just long enough to mate, lay their eggs and then die. Students, watershed groups, and professional biologists can use these animals to help them gage the health of our streams.

The following slide show is not a guide to benthic macroinvertebrate identification, although you will probably recognize some after seeing them here. Instead, we hope you will learn something about the important roles these animals play in our stream ecosystems.

All of the insects in this slide show were captured in just a few minutes in a small headwater stream on a cold day in January. A healthy stream is always full of life.

*Benthic macroinvertebrates are bottom living animals without backbones you can see without magnification.