Invertebrates include all of the animals lacking an internal skeleton of bone or cartilage
Many are microscopic; macroinvertebrates are those that may be seen without magnification
Biologists often use macroinvertebrates to assess the health of waterbodies
The composition of the invertebrate community tells a story.Some groups are very sensitive to pollution , others are very tolerant, some are sensitive to specific types of pollution (nutrients, heavy metals etc).
Identifying species within each group typically requires a microscope and years of dedicated study
With few exceptions identification here is at the Family level or higher
