In and Out of Water

Part of the Water: H2O = Life exhibition.

Life in water has both advantages and drawbacks. So some animals live in the water only when the need arises. Some frogs and insects, for instance, spend the early parts of their lives in water. Other animals, such as otters, move easily between water and land. And as bad as it may sound to be a fish out of water, some fish voluntarily crawl onto land when it suits them.

Atlantic mudskipper (Periophthalmus barbarus)
© Stephen Dalton/Minden Pictures

Invasion of the Snakeheads

The northern snakehead is a voracious predator and can wriggle its way from pond to pond, breathing air for short periods. With a large mouth and sharp teeth, it devours other fish and sometimes the occasional small bird or mammal. Snakeheads are native to Asia and Africa, but people have transported some species to other continents. They have been spotted in ponds, canals, and streams in several U.S. states. And like other invasive species, snakeheads pose a serious threat to native fish.

An Aeshna dragonfly nymph eating a stickleback fish
© Stephen Dalton/Minden Pictures

From Swimming to Flying

Dragonflies spend the first several months of life in water, and the rest of it almost entirely in the air. Juvenile dragonflies, called nymphs, crawl around ponds, feasting on other insect larvae and even small fish. If threatened, a dragonfly nymph can escape by squirting a jet of water from the gill chamber in its tail. Once fully developed, the dragonfly climbs out of the water, sheds its old skin and flies away, rarely visiting the water again until it's time to lay eggs.