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Aquatic Invertebrates

A beetle of the genus Peltodytes.
An aquatic beetle of the genus Peltodytes.

Another View of Plants

 

Essential Animals

Water mite.
Water mite.

Freshwater invertebrates are an incredibly diverse, although generally inconspicuous, group of animals. Despite their low profile, they play such an essential role in the aquatic ecosystem that the River as we know it would not exist without them.

Leptocerus americanus.
This Leptocerus americanus protrudes from its case to feed.

For example, aquatic insects are important because they recycle nutrients (they eat dead and decaying plant and animal matter and bacteria like E. coli) and they are a primary source of food for other animals and certain plants.

Not Only Insects
In the Rideau River, many of the aquatic invertebrates are the larval stages of insects, such as caddisflies, mayflies, dragonflies, mosquitoes and chironomids. However, there are many other invertebrates, including crayfish, worms, mussels, snails, and leeches. Some of the less visible and perhaps more unfamiliar invertebrates include many of the crustaceans (amphipods, copepods and ostracods), flatworms and water mites.

Aquatic snail of the Physidae family.
Aquatic snail of the Physidae family.

Aquatic invertebrates occupy many different feeding niches, from deposit feeders and filter feeders to herbivores and predators, which feed on other invertebrates or even small vertebrates like tadpoles, frogs and small fish.



150 Species in the River!
During 1999, the Rideau River Biodiversity Project scientists and volunteers identified more than 150 species of invertebrates living among submerged aquatic plants in the Rideau River. Many were photographed live under a microscope. These photographs are an invaluable resource.

Crayfish.
Crayfish.
During the summer of 2000, the invertebrates that live on the river bottom were sampled by taking sediment cores. The identification of hundreds more species is expected to result from the analysis of these cores.

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Neoplea striola feeding on a hydra.
Visit our photo gallery to see more gripping scenes like this one of Neoplea striola devouring a hydra.
A Project of the Canadian Museum of Nature
  
 Images: Christopher Allaway, Ed Hendrycks, André Martel