Macroinvertebrate Resources

Isopoda (aquatic sowbug)

Isopoda (aquatic sowbug)

Macroinvertebrates are animals without a backbone that can be seen with the naked eye. These bottom-dwelling animals include crustaceans and worms but most are aquatic insects. Beetles, caddisflies, stoneflies, mayflies, hellgrammites, dragonflies, true flies, and some moths are among the groups of insects represented in streams. Macroinvertebrates are an important link in the food web between the producers (leaves, algae) and higher consumers such as fish.

Macroinvertebrate Identification Resources

Other Websites

Visit Stroud™ Water Research Center’s Leaf Pack Network® website to learn about a simple experiment that uses tree leaves and aquatic insects to determine the health of your local stream.

Guide Books

The following books are recommended resources. Check your local library; they are also available for purchase from online booksellers.

  • McCafferty, W. P. 1981. Aquatic entomology: the fishermen’s guide and ecologists’ illustrated guide to insects and their relatives. Jones and Bartlett Publishing Company, Boston, Massachusetts.
  • Voshell, J. Reese. 2002. A guide to common freshwater invertebrates of North America. The McDonald & Woodward Publishing Company, Blacksburg, Virginia.

Taxonomic Certification Program

The Society for Freshwater Science Taxonomic Certification Program was implemented to certify that trained and skilled persons are providing aquatic invertebrate identifications in North America. The certification program tests a candidate’s knowledge and skills in aquatic invertebrate taxonomy and provides the successful applicant with a certificate of proficiency. The program also helps promote undergraduate and graduate training of new taxonomic experts, training of taxonomic technicians through workshops, development of new manuals for identifying aquatic invertebrates, and taxonomic excellence in other disciplines and other parts of the world.

Stream Sampling Information

Protocols and Fact Sheets

Stream Sampling License and Permit Information

Citizens from outside Pennsylvania should consult with the appropriate state agency for permit requirements.

Pennsylvania law requires anyone 16 years of age or older collecting aquatic organisms for any reason to have a valid fishing license and follow current Pennsylvania Fish & Boat Commission regulations.

High school and undergraduate college students are exempt from the license requirement if their teacher/educator applies for and is issued an Educational Aquatic Field Study Permit. For more information, visit the Pennsylvania Fish & Boat commission website.

Macroinvertebrate News

Online Atlas of Aquatic Insects Aids Water-Quality Monitoring
Online Atlas of Aquatic Insects Aids Water-Quality Monitoring
A new online field guide promises to be an important tool for monitoring water quality and learning how to correctly identify freshwater insects ... Read More
Get Your Freshwater Science Taxonomic Certification
Get Your Freshwater Science Taxonomic Certification
Through the accurate and precise identification of these organisms, you will be better prepared to record taxonomic data for biomonitoring programs ... Read More
Students working on designing a 3-D macroinvertebrate model
Life Lessons in Three Dimensions: Students, Stroud Center, Retired Teacher Collaborate
By creating these teaching tools for other students to learn about freshwater ecosystems, the students developed their own curiosity about their outdoor environment ... Read More
Screenshot of Caddisflies, Engineering an Ecosystem video
Research Reveals Caddisflies are Ecosystem Engineers
Hydropsychid caddisflies spin silk mesh nets that they use to filter feed. These nets are important ecosystem engineering structures in flowing waters ... Read More
Isopoda (aquatic sowbugs)
Test Your Skills With the #MysteryMacro Quiz
Want a fun way to learn about freshwater macroinvertebrates? Check out the Pennsylvania Fish and Boat Commission #MysteryMacro quiz featuring photos by Dave Funk ... Read More
Stroud Science on NPR: Road Salt Boosts Safety But Threatens Fresh Water
Stroud Science on NPR: Road Salt Boosts Safety But Threatens Fresh Water
When StateImpact Pennsylvania wanted to understand how our addiction to road salt is impacting the environment, they came to Stroud Water Research Center ... Read More