Lakes contain salmon, catfish, trout, walleye, and perch. Lake char and lake sturgeon are freshwater-only, however eels and salmon can live in saltwater. Lake fish feed ecosystem species.
Fish
Ducks have about 160 species. Ducks live in lakes on every continent but Antarctica. Some ducks eat on the lake's surface, while others dive for food.
Ducks
Loons yodel. Loons have problems walking on land, but they're strong swimmers and can find fish, frogs, and snails underwater. Because loons can't digest food, they consume lake stones.
Loons
These carnivorous mammals hunt in rivers and lakes. Otters consume fish but also frogs and crayfish. Otters float on their backs when not hunting.
Otters
These amphibians live in lakes. Some salamanders, like mudpuppies, are aquatic, while others, like long-toed salamanders, swim. Salamanders can interact using pheromones but not sound.
Salamander
Geese are waterfowl that live around lakes. Lakes provide food and shelter for geese. A skein of geese in the air is called a gaggle on the water.
Geese
Many bat species seek protection around lakes, despite being cave-dwellers. Bats are nocturnal and feed on flying insects like mosquitoes at night. Bats drink from lakes.
Bats
Some snails have gills and can spend most of their life underwater, whereas others have lungs and must surface for breath. Lake snails eat plants and algae, but they may also devour bugs and animals.
Snails
Few lake-dwelling frog species number over 5,000. Pacific tree frogs and actual frogs live in lakes. As adults, many frog species grow limbs from tadpoles.