The northern snakehead (Channa argus) has a most unusual ability: It can breathe outside of the water, as well as within. Juveniles can also wriggle their long, narrow bodies onto land, enabling them to travel from one pond or stream to another if needed.

This aggressive fish is native to China, southern Siberia, and North Korea, where it is fished and occasionally raised for food. But it’s also been introduced around the world, including most recently, the United States, where the invasive species has caused environmental problems.

The fast-growing creatures are carnivorous, eating zooplankton when they are young, but quickly progressing to insects, small amphibians, and other fish.

These fish, whose elongated bodies earned them their name, can grow up