Below the glimmering surface and along the shore of the Great Lakes live over 3,500 plant and animal species. Lakes Superior, Huron, Michigan, Erie and Ontario comprise the freshwater lake system collectively known as the Great Lakes. They play a critical role in the health of our ocean and aquatic life. Have you ever wondered what creatures call the Great Lakes — and the rivers and streams connected to them — home? This Earth Month let’s meet some familiar faces in these bustling ecosystems and in Shedd’s At Home on the Great Lakes gallery.
1. Central newt
Range: ponds, swamps, lakes and slow-moving streams.
This small salamander packs a powerful punch when defending itself from predators. The central newt (Notophthalmus viridescens louisianensis) has a toxic skin secretion that makes it taste unpleasant to predators.
Newts snack on small insects, worms and invertebrates. This contributes to insect population control, which can be beneficial to humans. Fewer mosquitos mean a more pleasant summer for us all. Thanks, newts!
Amphibians, like newts, are an indicator species, meaning their presence or absence reflects an environment’s health. Pollution contaminates water sources and directly impacts newt populations. Shedd is working toward a plastic-free future that tackles plastic pollution impacting wildlife. To make an impact, join Shedd on a Woodland Habitat Restoration day.
2. White sucker
Range: freshwater lakes throughout Canada and Eastern United States.
The white sucker (Catostomus commersonii) gets its name from its unique vacuum-like mouth, which it uses to slurp up algae, crustaceans and insect larvae from the lakebed – no teeth required!
In the spring, suckers begin a long migration from the Great Lakes to thousands of creeks and rivers to spawn, which gives an unexpected boost to the food chain. Suckers leave behind sustenance like nitrogen and phosphorous, creating a buffet of nutrients that helps algae flourish and bugs grow.
Shedd's Director of Freshwater Research, Karen Murchie Ph.D., is part of a team studying the migratory fishes of the Great Lakes, including suckers. Monitoring the ongoing shift of migration of these species caused by the rise in water temperature allows us to dive deeper into the local impacts of climate change. Find time to connect and appreciate suckers in At Home on the Great Lakes gallery.
3. Alligator snapping turtle
Range: river systems, lakes and wetlands.
A powerful name like the alligator snapping turtle (Macrochelys temminckii) leaves little to the imagination. As its name suggests, this turtle has a powerful snapping jaw that easily traps prey. To lure in an unsuspecting animal, the turtle opens its mouth and uses its worm-like tongue to trick fish into swimming inside. The result: a tasty meal and a balanced fish population.
Despite its strong defense against natural predators, alligator snapping turtles face challenges, particularly from humans. The effects of hunting have led to the turtle becoming endangered in Illinois. Additionally, destruction of freshwater habitats like wetlands has made it difficult for these animals to survive.
Man-made floating wetlands, like those Shedd helped to construct on the South Branch of the Chicago River, can increase food sources and serve as an oasis for aquatic wildlife like snapping turtles. Austin Happel, Ph.D., research biologist at Shedd, is studying benefits of floating wetlands and how fish move through the Chicago River.
4. Bluegill
Range: lakes, ponds, swaps, creeks and rivers with warm water.
You can spot the bluegill (Lepomis macrochirus), Illinois’ state fish, by the black spot on its earflap. This native fish is often spotted along the harbor south of Shedd Aquarium. Its nests are easily distinguished by a bowl-shaped pit in shallow water. Try to spot one on your next summer visit!
The bluegill’s shape makes it a difficult snack for herons and river otters to swallow, a natural defense against predators. Often, bluegills serve as prey for larger fish.
Maintaining clean water helps species like bluegill thrive. Join Shedd’s Litter Cleanup and Coastal Habitat Restoration along Lake Michigan and the Chicago River or invest in a pollution-free future by using reusable products like fabric bags, water bottles and glass food containers.
5. Lake sturgeon
Range: large rivers and lakes.
Lake sturgeon (Acipenser fulvescens) first appeared in fossil records around 136 million years ago, earning them the title of living fossil. This species is the largest and oldest fish native to the Great Lakes!
Four barbels spring from its snout and help this creature detect insects, crustaceans and small clams along the bottom of the lake. Lake sturgeons contribute to a balanced ecosystem by keeping invasive species populations at bay.
Along with other freshwater animals, lake sturgeons are impacted by the increase in dams and overfishing. Sturgeons are slow to reproduce, which emphasizes the importance of safe spawning grounds and infrastructure such as dams limit this. To interact, touch and learn more about sturgeon, visit Sturgeon Touch.
Other species you may recognize and can visit at Shedd:
Largemouth bass (Micropterus salmoides): One of the largest largemouth bass ever recorded weighed 22lbs!
Channel catfish (Ictalurus punctatus): The common catfish has taste buds all over its body.
Green sunfish (Lepomis cyanellus): Green sunfish can resemble bluegills, and it may be difficult to tell who’s who! Green sunfish are greener and have larger mouths.
Pumpkinseed fish (Lepomis gibbosus): The pumpkinseed name comes from the fish’s shape, not its colorful spots.
Common carp (Cyprinus carpio): Common carp belong to the Cyprinidae family, which includes minnows and carps.
Black crappie (Pomoxis nigromaculatus): Black crappie tend to form schools and often feed in the morning.
Longnose gar (Lepisosteus osseus): Gar camouflage as floating logs in the water, with younger gars looking like tiny twigs.
Walleye (Sander vitreus): Walleye tend to eat at night.