Guide to Aquatic Invertebrates

This resource is designed to provide a better understanding of the wide vareity of aquatic invertebrates found in our rivers, streams and wetlands. In addition to images, general information is included about the distinguishing features of the aquatic stage that aid in identification, and a scale for the organisms feeding group, tolerance, size range and habitat.  Larval and adult images are also provided for many families. Note: Benthic illustrations are courtesy of the Cacapon Institute and artist Jennifer Gillies.  

Aquatic invertebrates are excellent indicators of watershed health because they: Live in the water for all or most of their life; stay in areas suitable for their survival; are easy to collect; differ in their tolerance to amount and types of pollution; are easy to identify in a laboratory and in the field; often live for more than one year; and are important components of a streams nutrient and energy system.

Plants and animals are classified according to a hierarchal system that arranges the organisms into groups based upon their similarities. These groups are arranged from general to very specific. The science of classification is known as taxonomy

Insect Groups Non-Insect Groups
Ephemeroptera (Mayflies)

Arachnida (Spiders and Mites)

Plecoptera (Stoneflies)

Crustacea (Crayfish, Scuds, Sowbugs etc.)

Trichoptera (Caddisflies)

Annelida (Leeches and Worms)

Lepidoptera (Moths)

Turbellaria (Flatworms)

Odonata (Damselflies and Dragonflies)

Gastropoda (Snails)

Coleoptera (Beetles)

Bivalvia (Clams and Mussels)

Hemiptera (True Bugs) Hydrozoa (Jellyfish)

Megaloptera (Alderflies and Fishflies)

Spongilla (Sponges)

Diptera (True Flies)

Functional feeding groups

Collembola (Springtails)

Glossary of select terms 

Neuroptera (Spongillaflies)

Evaluating biological integrity

 Click-Here to download the SOS advanced BMI guide or HERE for a  quick guide to select aquatic insect families.
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