Cyanea capillata, commonly known as the lion's mane jellyfish, is a large species of jellyfish found in the northern Atlantic and Pacific Oceans. It is recognizable by its long, flowing tentacles that can reach up to 30 meters (98 feet) in length. The jellyfish has a bell-shaped body that can vary in color from reddish-brown to blue. This species is known for its stinging cells, which can cause painful reactions in humans. Cyanea capillata primarily feeds on small fish and plankton, using its tentacles to capture prey. It plays a role in the marine ecosystem as both a predator and prey for larger animals like sea turtles.