Starfish, or more technically accurate, sea stars, are fascinating creatures and amazingly diverse. Most commonly thought of as a five-armed intertidal species, starfish come in myriad shapes, sizes, colors, arm counts, and are found from shorelines to the deep sea. And while they seem like docile creatures, they can actually be voracious and rather savage predators. Here are some of the many beautiful, odd and surprising species of sea stars around the world.
Leather star (Dermasterias imbricata)
Leather star (Dermasterias imbricata):Found along the west coast of North America, from Alaska to Mexico, the leather star lives in the intertidal zone down to depths of about 300 feet where it dines on everything from algae to sponges to sea cucumbers. Meanwhile, it does its best to avoid the morning sun star, another species of sea star that makes a quick meal (well, relatively speaking) of the leather star. Leather stars make up to 50% of the diet of the morning sun star.
Morning sun star (Solaster dawsoni)
Morning sun star (Solaster dawsoni): And here is that voracious predator. With anywhere from 8 to 16 arms and usually red or orange coloring, the morning sun star looks, well, like a cartoon sun. It is found in the northern Pacific, from Japan to Siberia and down the coast of North America down to California. Other sea stars literally run away from it if they’re touched by it. Some, however, fight back, including the velcro star and rainbow star which can pinch the morning sun star to make it recoil and provide a window for escape. Others have defense mechanisms — the slime star inflates itself and exudes a noxious mucus, and the sunflower sea star can detach an arm in order to get away. If a morning sun star can’t catch a star of a different species, it has no problem chowing down on an individual of its own species.
Sunflower star (Pycnopodia helianthoides)
Sunflower star (Pycnopodia helianthoides): The sunflower star is the largest sea star in the world, reaching an armspan of 3.3 feet. That space is taken up by 16-24 arms. They’re found along the coast of North America, from Alaska to California, but they’re largest in the northern areas. They dine on sea urchins, clams and snails and are usually found in subtidal areas where there is always water, since they can’t support their bodies out of water.
Granulated sea star (Choriaster granulatus)
Granulated sea star (Choriaster granulatus): This species goes by many names, including the cushion sea star or doughboy star, for obvious reasons. The plump starfish is found in shallow waters on coral reefs and rubble slopes where it feeds on algae, coral polyps, and scavenges on dead animals.
Royal starfish (Astropecten articulatus)
Royal starfish (Astropecten articulatus): This vividly colored species is found along the east coast of North America, primarily in the southeast. While it can live at depths of up to 700 feet, it mostly hangs out at around 70-100 feet deep where it dines on mollusks. Unlike many other species of starfish, the royal starfish eats its prey whole.
Bat sea star (Asterina miniata)
Bat sea star (Asterina miniata): This fascinating species is called the bat star because of the webbing between its arms, which (so some say) look like bat wings. It is found along the west coast of North America, from Alaska to Baja. While the species usually has five arms, it can have up to nine, and it can be a wide range of colors from green to orange to purple. So if you’re wondering if you’re looking at a bat sea star, check if it has the tell-tale webbing.
Crown-of-thorns starfish (Acanthaster planci)
Crown-of-thorns starfish (Acanthaster planci): The name of this species is fairly clear. The spines covering its upper surface make it look like, well, you know. Those spines are also venomous, which aid it in its quest for world domination. Found over a wide range in subtropical waters, from the Red Sea to across the Indian Ocean, and across the Pacific Ocean to the western coast of Central America, this species preys on coral polyps. As one of the largest starfish in the world, it has a voracious appetitive. When numbers are low, crown-of-thorns starfish help boost the biodiversity of coral reefs by preying on the fastest growing coral species. But if their populations become too high, they can wreak havoc on coral reefs. Their population booms are due in part from human fishing of and collection of their natural predators, the humphead wrasse and triton snail.
Egyptian sea star (Gomophia egyptiaca)
Egyptian sea star (Gomophia egyptiaca): Found along the coasts of eastern Africa and Madagascar, this spiky sea star stays at depths of around 20-25 feet. Like may starfish, it can regenerate parts of its body that are damaged. But with those spikes, it doesn’t look like a sea star you want to reach out and mess with.
Blue sea star (Linckia laevigata)
Blue sea star (Linckia laevigata): This gorgeous blue sea star is found in the tropical waters of the Indian and Pacific Oceans, usually in shallow and sunny parts of reefs and reef fringes. It is a scavenger, and so acts as the clean up crew by feeding on dead animals. Like the chocolate chip sea star, the blue sea star has been part of the sea-shell trade for a long time, its skeleton sold as decoration. Because of this, the populations in some regions have seen dramatic decline.
Panamic cushion star (Pentaceraster cumingi)
Panamic cushion star (Pentaceraster cumingi): Talk about gorgeous. This beautiful species is found around the Gulf of Panama and the Pearl Islands, all the way up to the northern parts of the Pacific Ocean. Appropriately, it is also called a knobby star. They can reach up to 18 inches in diameter, and feast on mussels and barnacles. They are considered a keystone species in tidepools thanks to the work they do to keep mussel populations under control. But it’s not without effort — it can take a starfish upwards of six hours to eat a single mussel.
