Basket Star

A sunflower sea star is draped moplike over a
seafloor rock off the British Columbia coast.

A close-up reveals the backside of a sea star in Indonesian waters.
This star boasts a full complement of five arms but it may not
always keep them.

A colorful sea star heads toward a bed of mussels in Clallam Bay, Washington.

Crown-of-thorns sea stars—like this group on Kingman Reef in the Pacific—can inflict a painful sting to humans, but they are far more dangerous to corals.

Some 2,000 sea star species live throughout the world’s oceans. Some weigh as much as 11 pounds (5 kilograms) and stretch more than 2 feet (65 centimeters) across, but others are only half an inch (1 centimeter) in diameter.

Like sand dollars and sea urchins, sea stars are echinoderms,
those of the “spiny skin.”

Arching Sea Star

Sea stars are remarkable for what they lack. They have no

blood, but instead use filtered seawater to circulate nutrients
throughout their bodies

A sea star sits on the bottom of a shallow cove in Belize