On Exhibit: Open Sea
bell up to 2 feet (61 cm) in diameter, tentacles extending 20 feet (6 m) in length
lion's mane jelly; Family: Cyaneidae
eastern Pacific temperate waters from the Gulf of Alaska to Chile, Eastern Pacific, the Atlantic and the Mediterranean
Like a large bird egg cracked and poured into the water, that three-foot, translucent bell is yolk-yellow at the center, with hundreds of tentacles clustered around the margin. The egg-yolk jelly is one of the larger species of jellies commonly found in Monterey Bay. This massive jelly usually drifts motionless or moves with gentle pulsing. Acting like an underwater spider web with a mild sting, an egg-yolk jelly captures other jellies that swim into its mass of tentacles.
Many animals rely on egg-yolk jellies and other gelatinous creatures for food, including sea turtles, at least 50 species of fishes (like the ocean sunfish) and marine birds (like the northern fulmar). These animals can mistake a plastic bag for a jelly, and then get sick or die when they eat it. Help keep harmful plastics and other trash out of the sea—one simple way is by using cloth or paper bags instead of plastic when shopping.
Egg-yolk jellies sometimes carry passengers: crabs and amphipods have been found hitchhiking inside and on top of their bells. Young jack fish often can be found swimming among their tentacles.