Antarctic Sun Starfish
Also known as the wolftrap starfish, the Antarctic Sun starfish goes by its scientific name Labidiaster annulatus. With its 50 long and narrow arms, it gives the appearance of the Sun brimming with its rays. These arms also give the starfish its large size, with a diameter of up to 60 centimeters across. As its name indicates, it mostly lives in Antarctic waters, but populations also exist in the South Atlantic, such as in South Georgia and the South Sandwich Islands.
The Antarctic Sun starfish also has a predatory disposition, frequently climbing on top of rocks and spreading its arms into the surrounding water. Whenever small fish or marine invertebrates pass by, it lashes out and catches them before pulling them into its mouth. Because of its remote habitat, the Antarctic Sun starfish largely remains a mystery to marine biology to this day.
Australian Southern Sand Star
Also known by its scientific name, Luidia australiae, the Australian southern sand star counts as one of the more common starfish found around Australia and New Zealand. The Australian southern sand star has long and narrow arms, with most specimens having seven arms. This starfish typically has a dull brown color, with irregular patterns of either black or green spots. At its largest, it can grow up to 40 centimeters.
The Australian southern sand star also has a carnivorous diet, something that is referenced in its name. In particular, this starfish half-buries itself in the sand, allowing it to pounce on unsuspecting prey. Scientists have also observed it scavenging on the remains of other predators’ prey.
Basket Starfish
This is the common name given to a group of several starfish species known as Gorgonocephalus. It refers to their appearance, with a mass of coiling arms that resemble the Gorgon Medusa’s head full of snakes from Greek mythology.
Their large size and delicate features, however, make them very attractive for professional aquariums. In particular, their limbs can grow up to 70 centimeters long, with a single basket starfish weighing up to 5 kilograms. This means that only very large aquariums, typically with around 700 liters of water, can house a basket starfish. Together with their nocturnal filtering habits, basket starfish pose a challenge for even professional aquarium keepers.
Bat Sea Star
Also known as the sea bat, or the broad-disc star, and by their scientific name, Patiria miniata, the bat sea star’s name references how it grows webbing between its arms, resembling those of a bat. Bat sea stars usually have only five arms, but some specimens can grow up to nine arms.
This species of starfish also comes in many colors, ranging from green, purple, and red, to brown, orange, and even yellow. Their coloring may also either come in a single uniform monochrome, or in mottled patches of several different colors.
Sea bats live across the whole length of the Pacific coast of North America. People have found sea bats as far north as Sitka in Alaska, all the way south to Baja California.
Biscuit Starfish
Also known by its scientific name, Pentagonaster duebeni, the biscuit starfish takes its name from how it more or less has the size of a large biscuit. Biscuit starfish typically have only five arms, which can grow up to 8 centimeters long. They come in either orange, red, or yellow color, with white natural armor plating on the edges of their arms and central disc. They also live fairly close to the surface, only living down to depths of 160 meters at most. Biscuit starfish also make up an interesting paradox among starfish. In particular, they’re among the most commonly-documented starfish in the world but have only received limited scientific attention.
Blue Sea Star
Also known as the blue linckia, or by its scientific name Linckia laevigata, this starfish’s name references its rich blue color. This has also made the starfish a staple of the seashell trade, whether as preserved specimens or as living additions to aquariums. Of course, naturally, this causes a drop in the populations of the blue linckia across the Indo-Pacific region.
They typically grow up to 30 centimeters across, with some specimens featuring spots in other shades of blue over their arms. They also have yellow tube feet to help them move around, contrasting sharply with their otherwise uniform coloring. The blue linckia has a carnivorous diet, with scientists even suggesting they have a role in natural pest control.
Brisingid Sea Star
Much like the basket starfish, the brisingid sea stars refer to a group of several starfish species, the Brisingida. They take their name from the Brisingamen, a necklace belonging to the Norse goddess Freya in Norse mythology. According to the myth, Loki stole the Brisingamen and tossed it into the sea, thus inspiring this starfish group’s name.
Brisingid sea stars always have more than five limbs, which can grow up to six times as long as the width of the animal’s central disc. They live in both the Atlantic Ocean and the Pacific Ocean, ranging in depth from 100 meters to 4.5 kilometers below the surface.
Brittle Starfish
Another group of several starfish species, the Ophiuroidea takes its scientific name from its narrow and snake-like arms. These arms also have a delicate build and can get injured very easily, hence their common names of brittle starfish and brittle stars.
Brittle stars make up some of the biggest starfish in the world, with their arms able to grow up to 60 centimeters in length. Some of them even count among the world’s oldest species, with some species first evolving in the Ordovician Period, around 500 million years ago.
Most of them also like to live in deep water, at over 200 meters below the surface. Shallower species of brittle stars also make for popular additions to saltwater aquariums. However, they pose a challenge, as they can reproduce quickly and overwhelm an aquarium’s small ecosystem.
Brooding Cushion Star
It has the scientific name of Pteraster capensis and takes its name not from a habit of sulking in dark corners of the sea, but from how it keeps its brood of eggs between its outer and inner skins. This also gives the brooding cushion star a somewhat bloated appearance, and not just from the eggs. Specifically, the starfish must keep its eggs constantly in moving water to provide them with oxygen to stay alive. As such, the layer between its skins constantly remains full with both eggs and water. A native of South Africa, the brooding cushion star also makes up one of the smallest starfish in the world, with a diameter of barely 35 millimeters.
Brown Tipped Starfish
It has the scientific name of Thromidia catalai and takes its name from the brown color of the ends of its arms. Otherwise, the brown-tipped Starfish has a uniformly pink-tinted white color. It’s also known as the heavy starfish, or even the fat sea starfish, from how its arms resemble thick sausages.
This species of starfish can grow up to 65 centimeters, with a weight of 6 kilograms, making it one of the heaviest starfishes in the world. They live across the Indo-Pacific, with specimens found in Australia, Indonesia, Japan, and Hawaii. They also like to live in relatively deep waters, usually between 15 and 130 meters below the surface.
Carpet Sea Star
Another group of several starfish species, the Patiriella refer to how they tend to clump together, forming carpets of many starfishes across the seafloor. They also rarely have distinct arms, instead having a solid hexagonal or pentagonal body. They also come in a wide variety of colors. However, red and orange make up the most common colors they have.
Carpet sea stars live only in the Southern Hemisphere but have a widespread habitat regardless. People have found them from Australia and New Zealand all the way to Argentina and Chile in South America. In Australia’s Great Barrier Reef, carpet sea stars prefer to remain in rocky areas instead of open spaces.
Chocolate Chip Starfish
Also known as the horned sea star, and by its scientific name Protoreaster nodosus, it takes its name from its series of horn-like spines growing on top of its body that resembles chocolate chips. This starfish usually has a red or brown color, but also comes in tan, like cookie dough.
Chocolate chip starfish usually have five arms, but six or even four-armed specimens exist. They also typically grow up to 30 centimeters across and prefer shallow habitats that may become exposed during low tide.
Common Brittle Star
Also called the hairy brittle star, it has the scientific name Ophiothrix fragilis. It mostly lives along the West European coast, as well as the South African coast. It also comes in a wide variety of colors, ranging from gray, red, violet, and yellow. Many specimens also feature red spots, with pink bands over their arms. The arms themselves contrast with the vividly-colored discs of the starfish, usually only having a white or gray color.
Common brittle stars tend to densely live together, with scientists counting as many as 2,000 specimens in a single square meter. They think this results from their status as prey animals, leading to them clumping together for some form of protection in numbers.
Common Starfish
With the scientific name Asterias rubens, this animal comes to mind when one hears the word “starfish”. The common starfish has five arms and grows between 10 to 30 centimeters across, but specimens of up to 50 centimeters across do exist. It usually comes in orange or brown color, with some specimens having an unusual violet color instead. Common starfishes that live in shallower waters also tend to have a darker color compared to those from deeper waters.
Like most starfish, the common starfish has a carnivorous diet, preying on mollusks and other shellfish. The common starfish has particularly recaptured public interest in the 2010s, over mass stranding incidents. These involve hundreds or even thousands of animalsgetting washed up on the shore. Scientists still remain unsure about the cause, although storms and bad weather remain the main suspects.
Common Comet Starfish
Also known as the green Linckia, or Guilding’s sea star, this has the scientific name of Linckia guildingi. It takes its name from how detached arms from a common comet starfish can grow a new body of its own. This process takes a long time to even begin, with the detached arm taking at least six months before developing a new disc. From there, it takes another four months to grow other limbs, averaging about 10 millimeters long each. These contrast sharply with the massive original arm, making the new starfish appear like a comet, with a small, rayed “head”, and a long tail-like arm extending behind it.
Common Sun Star
With the scientific name of Crossaster papposus, it gets its name from its large population across both the North Atlantic and the North Pacific Oceans. It grows up to 30 centimeters across, colored red on top with alternating bands of dark red, pink, white, and yellow.
It also features a large number of brushlike spines on top of its body, with the spines growing long and larger on the edges of its body. In contrast, the common sun star has a uniform white color on its underside. Its disc also features a net-like pattern of raised ridges.
The common sun star has a predatory disposition, often attacking and feeding on small starfish and sea stars. However, it may also scavenge the carcasses left behind by other predators.
Crown of Thorns Starfish
The most infamous starfish of them all, it has the scientific name of Acanthaster planci. Its name comes from the venomous spines that grow all over its upper body, resembling the Biblical crown of thorns. However, its infamy instead comes from the fact that it primarily preys on coral, latching onto them and literally sucking them dry. Once it finishes eating all the polyps inside a coral, the starfish moves on, leaving only bleached, white, lifeless coral skeletons behind it.
In fact, this has actually earned the crown of thorns starfish a place among the world’s worst 100 invasive species. It even rivals global warming as the biggest threat to the world’s coral reefs. Thankfully, however, scientists have developed a way to control their spread. This involves using sodium bisulfate, which fatally poisons the starfish but has non-toxic properties against corals.
Cushion Star
It has the scientific name Culcita novaeguineae, and it takes its name from its short arms and inflated body. As the starfish typically folds its arms under its body, this gives it the appearance of a pincushion. Despite its short arms, its disc can grow quite large, enough to give the animal a diameter of 30 centimeters.
Cushion stars come in many colors, ranging from brown, green, orange, and yellow. They also never come in monochrome, and always feature mottling patterns of different colors.
Cushion stars also make up some of the most common starfish in the world, living all over the Indo-Pacific region. People have found them in places as distant from each other: Madagascar, the Philippines, New Guinea, Australia, and Hawaii.
Double Star Starfish
Also known as the icon star, it has the scientific name Iconaster longimanus. It takes its name from how the armor plating on its disc forms a star shape in the middle. The double star starfish has five arms and can grow up to 30 centimeters.
Its disc has an orange-brown color, which contrasts with the dark brown bands and tan edges of its arms. Widespread across the Indian and West Pacific Oceans, it’s especially common in Singapore where it feeds on oceanic plants growing on rocks.
Scientists think that the double star starfish may also feed on bacteria and microscopic invertebrates. However, they also admit that many mysteries remain about the double star starfish and that they continue to study the animal to unlock its secrets.
Doughboy Starfish
Also known as the granulated sea star and the big plated sea star, its scientific name is Choriaster granulatus. Its name refers to its chubby appearance, similar to 19th-century fried flour dumplings called doughboys.
Growing up to 27 centimeters across, it usually has a pale pink color, but other specimens have colors like gray, red, and yellow. Doughboy starfishes live in tropical waters stretching from East Africa in the west to Fiji and Papua New Guinea in the east.
They like to stay in shallow waters, from only 1.5 meters to 53 meters below the surface. Doughboy starfish commonly live in coral reefs, where they typically scavenge carcasses left by other predators. This has also left them vulnerable to the global decline of coral reefs as a result of global warming and other factors.
Eleven Armed Starfish
The largest starfish in Australia and New Zealand, it also has the scientific name Coscinasterias calamaria. As its name indicates, this animal has 11 arms, although specimens with up to 14 arms, or even with as few as seven arms exist. They typically have an average diameter of 30 centimeters. However, scientists have discovered that their arms have no uniform length. This comes from how the arms can easily get detached, and while the starfish can just grow them back, this results in irregular lengths between its arms.
A carnivore, the eleven armed starfish typically feeds on mussels, but will also feed on sea snails in the absence of mussels. Strangely, though, scientists have found that eleven armed starfishes grown in captivity prefer sea snails over mussels. They think this results from chemical responses made by sea snails in the wild when hunted by the starfish.
Feather Starfish
Feather starfish is another group of starfish species also known as the Crinoida or the Crinoids. They make up some of the oldest life forms on Earth, first evolving around 500 million years ago, even before recognizably-modern starfish.
Compared to their fellow starfish, feather starfish have small sizes, growing at most to a diameter of 25 centimeters. However, they have more arms than other starfish, at up to 200 arms in some specimens. This actually gives them their common name, as between their many arms and small size, they appear covered in feathers.
Feather stars today live in coral reefs, where they feed on the corals themselves. They’re also sometimes added to saltwater aquariums, but they pose a major challenge for professional aquarium keepers. This is because of their delicate environmental needs — even small changes in temperature or salinity could kill them. Similarly, copper salts, like those used to keep bacteria from growing in aquarium tanks, kill feather starfish instantly.
Firebrick Starfish
With the scientific name Asterodiscides truncatus, it takes its name from its reddish color and stone-like appearance. The latter, in particular, results from the nodes which grow between the armor plates that cover the starfish’s upper body.
The firebrick starfish lives only in Australia and New Zealand, with their habitats depending on the region. In Australia, the firebrick starfish prefer deep waters around 120 meters below the surface. In contrast, in New Zealand, they prefer to live on rocky reefs in shallow water.
The firebrick starfish mainly feed on sponges and other invertebrates living in kelp forests. They may also host small shrimps that feed on parasites and accumulated waste in its body. Scientists also consider the firebrick starfish as among the most mysterious and little-understood starfish species in the world.
Fromia Starfish
The Fromia make up another group of starfish species, which mostly live in the Indo-Pacific but also have populations in the Red Sea. Fromia starfishes typically only grow five arms, but some specimens may have seven. They also mostly have a deep red color, with some specimens featuring patterns of white dots.
Australia’s Fromia polypora also has an orange color that makes it distinct from other fromia starfish. Similarly, the Fromia schultzei species, also from Australia, has a pale red color distinct from other fromia starfish. Most other Fromia starfish actually have a reputation of being difficult to identify from each other.
Giant Spined Star
Also called the giant sea star, the giant spined star also has the scientific name of Pisaster giganteus. They take their name from their large size, with most of them having a diameter of up to 48 centimeters.
Their bodies also come in various colors, usually shades of brown, red, and violet. This contrasts with their spines, which have a blue color and tips that come in pink, violet, or white.
Giant spined stars live along the Pacific coast of North America, ranging from British Columbia in the north to California in the south. They also prefer to live in shallower waters, only living down to a maximum depth of 88 meters. They also have a carnivorous diet, preying on small marine invertebrates like barnacles and sea snails.
Green Brittle Starfish
With the scientific name Ophiarachna incrassata, green brittle starfish takes its name from its dull green color. It also refers to their delicate, worm-like arms, which it uses to move around but can also break off easily when struck. The green brittle starfish also uses these arms to sift through the seafloor and feed off any biomatter left hidden in the sand.
Common across the Indo-Pacific region, the green brittle starfish also makes for attractive additions to any marine aquarium. In particular, its feeding habits help make for a cleaner aquarium, however, professionals advise against adding small fish to any aquarium with green brittle starfish. This is because the green brittle starfish prey on smaller fish at times.
Leather Star
The leather star counts among the first starfish studied by modern scientists, in particular, by German zoologist Adolph Grube in 1857. He also gave the species its scientific name, Dermasterias imbricata. This comes from its leathery body, a natural adaptation to protect itself given the leather star’s lack of natural armor plating. A thin layer of mucus over its body adds further protection, while also giving it a garlic-like odor outside the water.
The leather star can grow up to 30 centimeters across, with a mottled pattern of red-brown and gray-blue. Native to North America, it lives across the Pacific coast from Alaska in the north to Mexico in the south.
Luzon Starfish
With the scientific name Echinaster luzonicus, it naturally takes its name from the northern island of the Philippines, Luzon. The Luzon starfish has six arms, as well as an asymmetrical shape resulting from its habit of irregularly shedding its arms. This then causes its arms to grow back with a similarly irregular growth rate between them.
That said, scientists have since discovered this habit of shedding serves as a form of asexual reproduction for the Luzon starfish, with the discarded arms growing into new starfishes. The Luzon starfish comes in various colors, which range between shades of red and brown. Aside from the Philippines, people have found the Luzon starfish in Indonesia, as well as in farther places like Australia and even East Africa.
Marble Starfish
An example of the Fromia starfish group, the marble starfish also goes by its scientific name Fromia monilis. Like others of its kind, the marble starfish has a red body, with a pattern of white dots. However, the marble starfish stands out thanks to its white dots also doubling as armor plating. They also grow only on the lower parts of its arms, as well as the outer parts of its disc. This also gives the starfish its name, as well as another name, the tile starfish, from how it looks like a marble tile. These distinct qualities make it easier to distinguish from other kinds of Fromia starfish.
Morning Sun Star
With the scientific name Solaster dawsoni, it takes its name from its appearance which resembles a sun with rays. The morning sun star has between 8 to 13 arms, all of which feature countless small pincers to get at prey.
In fact, the morning sun star makes up the most predatory starfish in its native North Pacific Ocean. So much so, that every other starfish it encounters runs before it could get close. Unfortunately, not all starfishes can move quickly enough to avoid getting caught, such as the leather star which is the staple food of the morning sun star. The prolific starfish comes in various colors: brown, gray, orange, and red.
Northern Pacific Sea Star
Also called the Japanese common starfish, this starfish also goes by the scientific name Asterias amurensis. As its names indicate, it lives in the North Pacific Ocean, but most commonly in Japan. It has five arms, while its upper body comes in various colors, such as orange, yellow, and sometimes red or even violet. In contrast, its lower body always has a uniform yellow color.
The Northern Pacific sea star has a bad reputation as an invasive species due to its notorious feeding habits. In particular, it feeds on mollusks and other shellfish, so much so that it can actually destroy entire harvests for fishermen. This forced many fishermen to resort to expensive water filtration methods to exterminate juvenile Northern Pacific sea stars.
Ochre Sea Star
Also called the purple sea star, it also goes by its scientific name Pisaster ochraceus. Widespread across the Pacific Ocean, it has five arms and grows up to a diameter of 25 centimeters at most. As its name indicates, it usually has a violet color, but other specimens sometimes have an orange, red, yellow, or even brown color.
Scientists have since discovered that ochre sea stars play an important role in keeping shellfish populations under control. They’ve also discovered that ochre sea stars have started altering their bodies in response to rising ocean temperatures. In particular, as rising temperatures make it difficult to filter calcium carbonate from the water, the ochre sea stars have reduced the density of their bones. At the same time, they’ve also increased their muscular density to compensate.
Pacific Blood Star
With the scientific name Henricia leviuscula, this starfish takes its name from its vivid blood-red color. That said, some specimens come in different colors, such as brown, gray, and even violet. Some specimens also feature lilac patches at the base of their arms.
They usually have five arms, but scientists have found specimens with only four or even six arms. They also make up some of the smallest starfish in the world, with a diameter of at most 12 centimeters.
Despite their name, Pacific blood stars aren’t especially widespread across the Pacific Ocean. Instead, they stick to their native North American waters, roaming the coasts of Alaska and California.
Paddle-Spined Seastar
It has the scientific name Patiriella parvivipara and has the distinction of being the smallest starfish in the world. At most, they grow only up to 5 millimeters, easily the size of a human fingernail.
Featuring six arms of its own, the paddle-spined seastar takes its name from its paddle-like spines, the purpose of which remains unclear to scientists. They know it doesn’t use them for movement, as microscope observation has shown the paddle-spined seastar using microscopic tube feet to move with instead.
The paddle-spined seastar is also one of the rarest starfish in the world. In fact, they only live in their native waters off the coast of Victoria in Southern Australia.
Panamic Cushion Star
Also known as the Cortez starfish and the knobby starfish, it has the scientific name Pentaceraster cumingi. It takes its name from Panama, where scientists first studied it, and the pattern of white knobs growing over its upper body.
The Panamic cushion star has five arms and grows up to a diameter of 30 centimeters. It lives across the Eastern Pacific, ranging from Hawaii and down the coast of the Americas from California to Peru. That said, the Peruvian population of the Panamic cushion star today stands close to extinction as a result of overcollection for use as souvenirs.
Pink Sea Star
With the scientific name Pisaster brevispinus, it has the fame thanks to Patrick Star from Spongebob Squarepants. As its name indicates, it has a pink color, though some specimens feature gray shades over their body.
It usually has five arms, as well as up to a diameter of 90 centimeters, making it one of the largest starfish in the world. The pink starfish lives in North American Pacific waters, ranging down the coast from Alaska to California.
It also has a predatory disposition, feeding on mollusks and other shellfish, while also hunting for buried clams. Scientists still aren’t sure how the pink sea star finds them, but scientists have observed the starfish digging down to uncover buried clams before prying them open to eat.
Rainbow Star
Also known as the red-banded sea star, it has the scientific name Orthasterias koehleri. It takes its name from its colorful appearance, with a pink or red body banded with other colors such as dark red, gray, and orange. Its body also features many small but sharp spines in white or mauve, with each spine having its own pincer.
The rainbow star also makes up one of the bigger starfishes in the world, growing up to a diameter of 50 centimeters. It lives along the Pacific coast of North America, from Alaska to California. The rainbow star also has a predatory disposition, feeding on shellfish, and even fights rather than runs from the equally-predatory morning sun star.
Red Cushion Sea Star
Also called the West Indian sea star, the red cushion sea star has the scientific name Oreaster reticulatus. It takes its other name from its home waters in the Caribbean Sea and the West Atlantic Ocean, the so-called West Indies. It’s actually the biggest starfish in those waters, growing up to a diameter of 50 centimeters, and usually with five thick arms. Although scientists have found specimens with up to seven arms.
Juveniles of this species have a mottled green color that turns red when they become adults. However, some West Indian sea stars also come in colors like brown, orange, and yellow. All specimens of red cushion sea stars have hardened upper bodies with blunt spines for protection. This gives it a deceptively soft appearance, hence the common name of red cushion sea star.
Red Knob Sea Star
Also called the red spine star, as well as the African Sea Star, this starfish has the scientific name Protoreaster linckii. It takes its name from the red-colored bony nodes that grow all over its upper body, with red markings on its skin connecting the nodes together. The starfish’s body itself has a dull gray color, which makes its nodes and markings stand out even more.
The red knob sea star grows to fairly average size for starfishes, with a maximum diameter of around 30 centimeters. It mostly lives in the Indian Ocean. However, scientists have found small populations of the starfish in Indonesia.
Red Starfish
Another member of the Fromia Starfish group, the red starfish has the scientific name Fromia indica. Like other Fromia starfish, it has a vivid red color, however, its juveniles feature black tips at the ends of their arms. This makes this easy to distinguish from other Fromia starfish, at least until the black tips disappear with adulthood.
Red starfish typically have five arms, but scientists have found rare specimens with six arms. They suspect these resulted from severe injuries, with the starfish’s body overreacting after losing an arm, making an extra one. The red starfish lives in the Indian and West Pacific Oceans, from Sri Lanka to Fiji, as well as from Japan to Australia.
Reticulated Starfish
It has the scientific name Henricia ornata and lives only in a small part of the South Atlantic off the Cape of Good Hope in South Africa. It takes its name from a fine, reticulated, or net-like pattern of black lines all over its body. The reticulated starfish usually has a red-brown body, but some specimens have a yellow body instead.
It prefers to live in shallow waters, with scientists finding specimens living at a maximum depth of only 50 meters. The reticulated starfish also like to live on reefs, where they feed on shellfish or scavenge carcasses left behind by other predators.
Royal Starfish
With the scientific name Astropecten articulatus, it takes its name from its vivid colors. The edges of its arms and disc form a solid orange border, with the rest of the starfish’s body having a rich violet color. White spines sticking out from its arms further add contrast to the starfish’s already striking appearance.
On average, they grow to a diameter of 30 centimeters, but some specimens can grow even bigger, up to 55 centimeters across. They mostly live in the Caribbean Sea, but some specimens live further out across the West Atlantic. Royal starfish usually feed on shellfish, but scientists have discovered circ*mstantial evidence pointing to the starfish also feeding on aquatic plant life.
Sand Sifting Starfish
Also called the sand starfish and the comb starfish, this starfish has the scientific name Astropecten polyacanthus. While all starfish can and do sift the sand on the seafloor for food, this is the only way that the sand sifting starfish could get food. This leads to a lean diet, which contributes to the starfish’s small size, with a maximum diameter of only 15 centimeters.
That said, this makes the sand sifting starfish especially popular for aquarium keepers. The sand sifting starfish’s habits not only help keep the tank clean, they also mean there’s less need to regularly feed the starfish. That said, professionals recommend against keeping the sand sifting starfish in a tank with predatory fishes and other starfish.
Six-Rayed Star
With the scientific name Leptasterias hexactis, it takes its name from the six arms it has. It’s also very small, with a maximum diameter of only 5 centimeters. The six-rayed star comes in various colors, such as brown, dark gray, and olive green. Scientists have also found rare specimens featuring a brick-red color.
This starfish also features a dense array of short, mushroom-shaped spines all over its body. Despite its small size, it has a very predatory disposition, attacking and successfully preying on shellfish for food. It can even compete with bigger starfishes, such as the ochre starfish, when hunting for food.
Spiny Cushion Star
With the scientific name Culcita schmideliana, this starfish takes its name from the small, conical spines that cover most of its body. It also features large, bony nodes that grow bigger the closer they get to the starfish’s mouth.
The spiny cushion star typically has a gray body with pink patches around its nodes, which stand out with their black color. Its mouth is also notable for its vivid orange color.
The spiny cushion star also has symbiotic relationships with other animals, such as pearlfish and shrimp. A pearlfish, in particular, usually lives in the starfish’s stomach, feeding on indigestible bits and pieces. It also helps keep the starfish free from parasites. Shrimp have a similar role in keeping the starfish’s skin healthy, feeding on rotting biomatter and would-be parasites before they can harm the starfish.
Spiny Starfish
This starfish has the scientific name Marthasterias glacialis andtakes its name from the white spines that cover its entire body. These spines stand out against the starfish’s body, which has gray-green color except at the tips of its arms, which have a violet color instead.
The spiny starfish also make up some of the biggest starfishes in the world, with some specimens growing as large as 70 centimeters across. They also have a carnivorous diet, feeding on shellfish and even other starfishes. That said, they’re also not very common, with the spiny starfish living only in the coastal waters of the British Isles.
Stimpson’s Sun Star
Also called the sun star, the orange sun star, and the sun sea star, this starfish has the scientific name Solaster stimpsoni. It takes its name from William Stimpson, an American scientist who identified the species during the 19th century. Its name also refers to its appearance, which resembles a sun with rays, much like its sister species the morning sun star.
The Stimpson’s sun star makes up one of the largest starfishes in the world, growing up to a diameter of 50 centimeters. Its arms typically number between 8 and 12. The starfish’s underside has a red-orange color, which contrasts with the violet color of its upper body. Stimpson’s sun star lives across the Pacific Ocean, predominantly from Japan to Alaska and to California.
Sunflower Star
Also called the sunflower sea star, it has the scientific name Pycnopodia helianthoides. It’s also the biggest starfish in the world, with its arms alone easily growing up to a length of one meter each. They also have many arms, averaging between 16 and 24 arms. Sunflower stars come in many colors, ranging from brown, red, violet, and yellow.
The sunflower star has predatory dispositions, with sea urchins as their most common prey. They also make up one of the most vulnerable starfish species in the whole world. Ever since 2013, rising ocean temperatures have caused its population to drop, made worse by viral infections. In fact, today the sunflower star has a critically-endangered designation from international organizations.
Velvet Sea Star
The velvet sea star’s scientific name is Petricia vernicina and it takes its name from its smooth and velvet-like skin. They tend to have red or orange-colored bodies, but some specimens instead have cream-colored bodies with red mottling. Many small sacs sprout all over their bodies, which scientists call papillae. This helps the starfish draw oxygen from the surrounding water.
Velvet sea stars don’t grow very large, with a diameter of around 16 centimeters at most. They’re also not very common worldwide, mostly living in the waters off of Southern Australia. Small populations of the velvet sea star also thrive on the islands near Eastern Australia.
Vermilion Star
The vermilion star’s scientific name is Mediaster aequalis. Its common is taken from its rich orange-red color. Vermillion stars usually have five arms, but some specimens have four or six arms. They also tend to have an average size for starfish, with a diameter of around 20 centimeters. Vermillion stars live off the Pacific coast of North America, from Alaska down to California.
They’re adaptable enough on both shallow and deep water, with people finding them during low tide, while scientists have found specimens from as deep as 500 meters below the surface. Vermillion stars primarily feed on algae but also prey on sponges and worms. They, in turn, get preyed on by other bigger starfish, such as the morning sun star.
