Down by the River

There are over 100,000 animal and plant species living in rivers. The Mississippi River has over one hundred species of fish.

American eels are a catadromous species, which means they live in freshwater during their adult life before migrating to the ocean to spawn. Once it has spawned, the eel dies. Adult American eels usually eat at night, feasting on small fish, worms, crustaceans, and mollusks.

Amazon River dolphins are also referred to as the boto. They have characteristically long, skinny beaks and round, bulging noses. Their long snouts let them dig through river mud for prey like crustaceans or swim through branches searching for fish. The belief that a boto can come ashore in human form wearing a hat to hide its blowhole.

American alligators live in preserved natural habitats mostly in the southeastern portion of the US in the states of Florida and Louisiana. Alligators have bodies covered with scales and clenching jaws. They are known to inhabit rivers but also make their homes in lakes, swamps, and marshes. Once out of the water, these animals can be rather heavy and clumsy. Underwater, alligators are expert swimmers. They prey on fish, small mammals, and snakes.

Belted crayfish are medium-small sized and tan colored, overlaid by green and red bands on their abdomens. Their pincers are narrow. They live in streams ranging from creeks to rivers and prefer soft currents and coarse rock. During the daytime belted crayfish hide underneath rocks and forage for food at night. They cannot traverse land. They’re known to inhabit the Meramec River and Big River in Missouri. These crayfish are omnivores and enjoy dining on many types of plants and animals.

Blue catfish can be found in the Ohio, Missouri, Mississippi, and Rio Grande River basins. They are listed as an invasive species in the Chesapeake Bay tributaries. These fish dine on clams, worms, crustaceans, insects, smaller fish, and frogs, but their diet changes by the season. During the spring, summer, and fall, the blue catfish prefers feeding on aquatic vegetation. When attacked by bald eagles and osprey, blue catfish use their serrated spinal barbs to defend themselves. The spines contain glands that release toxins, which can infiltrate wounds on the predators’ bodies and cause a great deal of pain. To avoid being preyed on, young blue catfish scour for food at night, rather than during the day, mainly eating zooplankton and tiny aquatic insects.

Blue crabs are named for their blue-colored claws. They have brownish shells. These crabs are among the most harvested animals on Earth. They are freshwater omnivores found from the lagoons of Nova Scotia to the Gulf of Mexico. Blue crabs feed on creatures they can easily come by, such as fish, plants, mussels, and even other blue crabs. They are well-adapted swimmers.

Brazos water snakes (pictured above) are confined to the northern parts of the Brazos River in Texas. They’re identified by their brown/gray or brown/green coloring. These snakes prefer living in water with fast currents, rocky floors, and lots of vegetation. Brazos water snakes hide under rocks or among vegetation. They dine on small fish but can also prey on crayfish, frogs, and salamanders.

Chain pickerels can be found anywhere from the St. Lawrence drainage in Canada to the state of Florida. They have been seen in the southern Mississippi drainage and throughout the state of New Hampshire. These fish have torpedo-shaped bodies, huge mouths filled with sharp teeth, and large dorsal and anal fins. They’re known to prey on other fish species as well as frogs, snakes, ducklings, and muskrats. When hiding from predators, they take cover in aquatic vegetation, where they also like to spawn.

Diving bell spiders are commonly referred to as water spiders. They spend much of their time underwater, seldom having to rise to the surface of the water.On land the spiders appear to have dark velvet-colored abdomens. Underwater they appear more silvery due to the air bubbles surrounding their abdomen. The hairs on their abdomen allow the spiders to capture air bubbles, creating a “diving bell.” The spider rises to the surface, captures a bubble of air, hauls the bubble underwater, and releases it under a canopy-like cover. Inside this diving bell the spider spends the majority of its time. The spider does almost everything in this sac, from eating to resting to reproducing, only coming up to the surface of the water to gulp air. The water spider prefers to prey on crustaceans as well as aquatic insects.

Red-eared slider turtles need to live in large habitats and areas where they can freely and easily move around. Young sliders have bright green shells. The carapace is the top portion of the shell, and the bottom part is the plastron. Both the carapace and the plastron are covered in scutes, which are bony plates with a keratin protein covering. Red-eared slider turtles are social creatures and expert swimmers spending a great deal of time underwater. They are omnivores that dine on fruits, fishes, amphibians, and underwater vegetation and invertebrates.

River frogs are similar in appearance to their bullfrog cousins; river frogs are fairly easy to distinguish by the light spots on their lips, especially on the lower jaw. They have rougher and more wrinkled skin across their bodies. River frog tadpoles exhibit schooling behavior, swimming together. These frogs can be found throughout the Coastal Plain of the southeast portion of the US. They inhabit a variety of habitats, among them rivers, creeks, and swamps.

River otters inhabit areas around rivers but are also known to live near lakes and streams. These are playful animals that enjoy sliding down muddy hills. They prefer to live near water that is bordered by woods or wetlands. They have long, slender bodies, webbed hind feet, and strong tails, They’re excellent swimmers and can stay underwater up to four minutes. While underwater, they keep their ears and eyes shut to prevent water from entering. They prey on fish, which is their primary food source. Once they catch their prey, they drag it onto the shore to eat.