Get Guide To Aquatic Invertebrates Of The Upper Midwest

While most invertebrates don't strictly hibernate, some will go into a state of 'diapause' - halting their development and spending the winter as either eggs, larvae, pupae, or adults, while some will slow down their metabolism in a state known as 'torpor'.

The kinds of aquatic invertebrates in freshwater systems include protozoans (single cell animals), freshwater sponges, various types of worms, mollusks (snails, clams, freshwater mussels), and arthropods (animals with jointed legs such as spiders, mites, crustaceans, and insects).

Ice helps protect most aquatic plants and animals throughout the winter months. As ice melts in spring, it absorbs heat from the environment to slowly change its state back to liquid.

Aquatic macroinvertebrates include insects, bivalves, gastropods, annelids, and crustaceans. Aquatic insect orders include Trichoptera, Ephemeroptera, Odonata, Megaloptera, Plecoptera, Diptera, and Coleoptera.

Aquatic invertebrates are an integral part of aquatic food webs, and in some cases are important in terrestrial food webs. They break down material from primary production (e.g., leaves, algae) and consume materials such as fungus, dead animals, and bacteria.

But there is still plenty of life in those streams when they start to freeze over. In fact, most aquatic macroinvertebrates live in streams throughout the winter. Water is an incredible insulator and resists changes in temperature. Although streams can freeze over, the ice is typically only a few inches thick.

Aquatic invasive invertebrates are non-native animals that lack a vertebral column (backbone) and spend the majority of their lives in freshwater, marine, or estuarine environments (including inland waters, riparian areas, and wetlands).

Aquatic macroinvertebrates encompass thousands of species with varied life history strategies, but most include three distinct morphological stages: the larval stage, the pupal stage, and the adult stage. The timing, length, and development of these stages vary from species to species.