Animals Wildlife 17 Bizarre and Beautiful Starfish Species Discover the chunky granulated sea star, the venomous crown-of-thorns, and more. By Jaymi Heimbuch Jaymi Heimbuch Twitter Writer California Polytechnic State University, San Luis Obispo Jaymi Heimbuch is a writer and photographer specializing in wildlife conservation, technology, and food. She is the author of "The Ethiopian Wolf: Hope at the Edge of Extinction." Learn about our editorial process Updated March 30, 2022 Treehugger / Catherine Song Share Twitter Pinterest Email Animals Wildlife Pets Animal Rights Endangered Species Starfish, also known as sea stars, are famously resilient, aesthetically alluring, and amazingly diverse. Commonly perceived as a five-armed intertidal species, these echinoderms come in many shapes, sizes, colors, and arm counts (as many as 40). There are some 2,000 starfish species around the world—some found along shorelines and others existing only in deep-sea environments. Here are 17 bizarre and beautiful species of sea star. 1 of 17 Leather Star Brent Durand / Getty Images Found along the west coast of North America, from Alaska to Mexico, the leather star (Dermasterias imbricata) lives in the intertidal zone down to depths of about 300 feet, where it dines on everything from algae to sponges and sea cucumbers. Meanwhile, it does its best to avoid and outrun the morning sun star, a common predator that we'll explore below. 2 of 17 Morning Sun Star Jonathan Martin / Flickr / CC BY 2.0 With anywhere from eight to 16 arms and usually red or orange in color, the morning sun star (Solaster dawsoni) resembles a cartoon sun but is much more voracious than it looks. Found in the northern Pacific, from Japan to Siberia and down the coast of North America, it preys on many of its relatives—the mottled sea star, striped sunflower star, rose star, slime star, and others—which try to outrun it, outsmart it, fight it, or play dead in its presence. Since sea stars are blind, large ones will often try to flee when touched by a smaller one because they do not know they have a size advantage. 3 of 17 Sunflower Star Jennifer Idol / Stocktrek Images / Getty Images The sunflower star (Pycnopodia helianthoides) is the largest sea star in the world, reaching an arm span of more than three feet. Found along the coast of North America—from Alaska to California, in subtidal areas where there is always water—it can have between 16 and 24 extremities. So, how does it get so big? By dining on sea urchins, clams, and snails. These sea stars are fast and efficient hunters, moving at a speed of 3.3 feet (1 meter) per minute. Their population is in decline, however, due to warming sea temperatures and increasing diseases. 4 of 17 Pink Sea Star jkirkhart35 / Wikimedia Commons / CC BY 2.0 The pink sea star (Pisaster brevispinus) can reach a whopping two feet in diameter and weigh up to two pounds, but it's most known for its bubblegum-pink color. You may recognize it as the inspiration behind Patrick Star of "SpongeBob SquarePants" fame. The real thing dines on clams and sand dollars, and is thus found on sand or mud. Its soft texture allows it to also grip on coral and rocks, where it can feast on mussels, tube worms, and barnacles. 5 of 17 Granulated Sea Star Reinhard Dirscherl / Getty Images The granulated sea star (Choriaster granulatus) has many nicknames: cushion sea star, doughboy star, big-plated sea star, and others pertaining to its characteristic plumpness. The only species in the genus Choriaster, this uniquely puffy starfish is found in shallow waters on coral reefs and rubble slopes, always tropical, where it feeds on algae, coral polyps, and dead animals. It prefers an above-average water temperature, ranging from 74 to 84 degrees Fahreneit. 6 of 17 Royal Starfish TheMargue / Wikimedia Commons / CC BY 2.0 The royal starfish (Astropecten articulatus) gets its name from its decadent purple and gold color. The vividly hued 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 to 100 feet deep, where there are plenty of mollusks to eat. Unlike many other species of starfish, the royal starfish eats its prey whole. 7 of 17 Bat Sea Star Raymond Gehman / Getty Images The fascinating bat sea star (Asterina miniata) is called so because of the webbing—resembling bat wings—between its arms. It is found along the North American West Coast, from Alaska to Baja. While the species usually has five arms, it can have up to nine, and it can occur in a range of colors, including green, orange, and purple. This sea star has "eyespots" at the end of each arm that are able to detect light. It uses sensors on its tube feet to "smell" and hunt its prey. 8 of 17 Crown-of-Thorns Starfish Gerard Soury / Getty Images The crown-of-thorns starfish (Acanthaster planci) is one of the largest sea stars in the world, and its upper surface is covered in spines (hence the name). To satisfy its extraordinary appetite, it eats stony coral polyps in the subtropical waters where it lives. Where crown-of-thorns exist in small quantities, they help boost the biodiversity of coral reefs by preying on the fastest growing coral species. But where their populations are high, they can wreak havoc on the reefs. Their population booms are due in part to fishing and collection of their natural predators, the humphead wrasse and triton snail. 9 of 17 Pacific Blood Star Ed Reschke / Getty Images Named for its red-orange color, the Pacific blood star (Henricia leviuscula) is common along the Pacific coast of North America, found at depths of more than 1,000 feet. It likes to hang out on rock and shell surfaces and is not commonly found on beaches except at very low tide. It's actually a very small, slender species—up to 10 inches in diameter—that feeds on sponges and bacteria. Its main predators are birds and humans. 10 of 17 Brisingid Sea Star NOAA Photo Library / Flickr / CC BY 2.0 The order Brisingida comprises 70 or so deep sea-dwelling starfish species. Residing at depths of 330 to 19,000-plus feet below sea level, they are suspension feeders, which means they use their six to 16 spine-covered arms to filter water and capture food as it drifts by. They resemble seaweed or coral more than they do traditional starfish. 11 of 17 Necklace Starfish imageBROKER / Norbert Probst / Getty Images Known for its jewel-like ornamentation and unusual, beguiling coloring, the necklace starfish (Fromia monilis) hails from shallow parts of the Indian Ocean and western Pacific Ocean. It feeds on sponges and small invertebrates and can get as large as 12 inches across. It's also called the red tile starfish for its elaborate design. Unfortunately, this sea star is also found in many an at-home saltwater aquarium. This isn't good, since it subsists exclusively on red sponges and most aquariums cannot provide that. These starfish usually die of starvation within a year of capture. 12 of 17 Giant Spined Star Hal Beral / Getty Images The giant spined star's (Pisaster giganteus) pedicellariae—minute pincers—present like pretty white, pink, or purple beads, but really, they help protect the animal from predators, such as sea otters and birds. The species can reach two feet in diameter and is found in rocky areas of the North American west coast, from southern California to British Columbia, along the low tide mark. It has remarkable regenerating capabilities. If it loses all but one of its legs, it will slowly regrow them; if it gets cut in half, it can regenerate the other half of its body. 13 of 17 Pincushion Starfish Gerard Soury / Getty Images Found in tropical waters of the Indo-Pacific, the pincushion starfish (Culcita novaeguineae) is unique in its inflated appearance, which can grow to a diameter of one foot (30 centimeters). Not physically similar to most traditional starfish, it creates its own little habitat within itself, providing water-filled shelter for small shrimp and copepods in the meantime. Even a species of fish, the star pearlfish, may take shelter inside this starfish's armored body cavity. 14 of 17 Chocolate Chip Sea Star Placebo365 / Getty Images Though the knobs on the chocolate chip sea star (Protoreaster nodosus) may look appetizing to humans, they look dangerous to predators. Because of this, the starfish actually protects other species, such as shrimp, tiny brittle stars, and juvenile filefish, that live on its surface. Due to being overharvested for tourist trinkets and the aquarium trade, humans are its greatest threat. These sea stars subsist on sponges and other detritus and are often found on coral reefs. 15 of 17 Blue Sea Star Marnie Griffiths / Getty Images This gorgeous blue sea star (Linckia laevigata) 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, feeding on dead animals, and has been coveted by the seashell trade for a long time. Because of this and reduced coral reef area, populations in some regions have seen significant decline. As with many sea stars, their mouth is on the underside of their body, but prey is "absorbed outside their mouths by forcing out their digestive organs from their stomach." 16 of 17 Australian Southern Sand Star John Turnbull / Flickr / CC BY-NC-SA 2.0 The mottled coloring of the Australian southern sand star (Luidia australiae) helps to camouflage it in the sediment of seagrass beds in the Pacific Ocean around Australia and New Zealand. Typically sporting seven arms, it can grow to be around 16 inches in diameter. It is sometimes found washed up on the beach after storms. 17 of 17 Panamic Cushion Star LASZLO ILYES / Flickr / CC BY 2.0 One of the most beautiful starfish of all, the Panamic cushion star (Pentaceraster cumingi), is considered a keystone species in tide pools thanks to the work it does to keep mussel populations under control. It's not without effort, of course—it can take upward of six hours for the starfish to eat a single mussel. These knobby, puffy stars are found around the Gulf of Panama and the Pearl Islands, all the way up to the northern parts of the Pacific Ocean. Unfortunately, it's nearly extinct in Peru, where its population has greatly decreased due to people buying the sea stars as souvenirs. View Article Sources "Sea Stars." National Aquarium. "Are Starfish Really Fish?" NOAA. "Critter News: Scary and Slimy Sea Stars." Seattle Aquarium. "Solaster dawsoni: Morning Sun Star." Race Rocks Ecological Reserve. Yagoda, Shayna. "Pycnopodia helianthoides." Animal Diversity Web. "Pink Sea Star." Georgia Aquarium. "Granulated Sea Star." iNaturalist.ca. "Astropecten articulatus (Say 1825)." Encyclopedia of Life. Wells, Harry W., et al. "Food of the Sea-Star Astropecten articulatus." The Biological Bulletin, vol. 120, no. 2. "Bat Starfish." The Dallas World Aquarium. "Bat star." Monterey Bay Aquarium. "Crown of Thorns Starfish (COTS)." Khaled bin Sultan Living Oceans Foundation. Bruckner, Andrew. 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