THE SPRING CREEK WATERSHED ATLAS

A female Callibaetis mayfly from Millbrook Marsh. Aquatic invertebrates are animals without backbones that live in water. Invertebrates that are too small to be seen with the naked eye are “microinvertebrates,” while those that can be seen without the help of a microscope are “macroinvertebrates.” Most macroinvertebrates are larger than 1 mm in size, and freshwater macroinvertebrates include thousands of species of insects, crustaceans, mites, molluscs (clams, mussels and sn

Among all the invertebrates in Spring Creek, crayfish probably have the most profound effect on the ecology of the stream, yet they are among the least noticed. During the day, you can carefully observe a small area of stream bottom and never see a single crayfish. If you were to go back to that location at night and shine a flash light on the bottom, it would be crawling with crayfish ranging in length from one to four inches. The Rusty Crayfish is characterized by a large