10 Rare Starfish Species You Likely Haven't Encountered

Sea stars, commonly known as starfish, are stunning and hardy marine animals. These echinoderms, found on the ocean floor, feature a central disc body protected by a robust calcium carbonate layer, offering structural support and safeguarding their intricate circulatory system and vital organs.

Starfish possess remarkable resilience, even capable of regrowing lost limbs. If a predator manages to break through their tough exterior, the detached arm heals itself, and specialized cells gather at the site to initiate the growth of a new arm.

These fascinating marine creatures also engage in asexual reproduction through a process known as binary fission. This occurs when the organism splits its cells into two genetically identical offspring. The eggs are subsequently fertilized by sperm released into the surrounding water, enabling self-fertilization.

Do Starfish Have a Brain?

Unlike most animals, sea stars lack a conventional brain. However, they feature light-sensitive "eyes" at the tips of their arms, enabling them to detect visible light. This adaptation allows them to flourish in sunlit, shallow waters like coral reefs and rocky shores.

Sea Urchins: A Sea Star's Favorite Snack

Sea stars are deliberate hunters, relying on their numerous tube feet to capture prey like sea urchins, clams, mussels, and small fish. These prey species often feed on algae and other marine organisms, making them a key part of the sea star's diet.

Starfish consume their prey by everting their stomachs. Their flexible stomachs extend outward through their mouths, bypassing the spines of urchins or the shells of clams to access and digest the soft tissues inside.

10 Sea Star Species You Can Find on the Ocean Floor

Narrowing down a list of well-known starfish is no easy task, given the vast diversity of over 2,000 species. Below are a few fascinating examples to quench your curiosity about these unique marine creatures.

1. Bat Sea Star (Asterina miniata)

This isn’t a superhero or a tool from the Dark Knight, but rather an intriguing starfish species. Named for the bat-like webbing between its arms, the bat sea star typically has five rays, though some individuals can develop more than nine.

2. Brisingid Sea Star (Brisingida)

These plant-resembling brisingids are among the deepest-dwelling sea stars, often found at depths exceeding 19,000 feet (5,791 meters). Their leaf-like arms filter water, allowing them to capture fleeting meals from unsuspecting prey and decaying organic matter drifting from above.

3. Crown-of-Thorns Starfish (Acanthaster planci)

If the ocean hosted a fashion show, these vibrant creatures would undoubtedly steal the spotlight. With their striking neon hues and spiny exteriors, they’re impossible to overlook — just hope you encounter them visually rather than stepping on their sharp spines.

4. Granulated Sea Star (Choriaster granulatus)

Fortunately, starfish lack ears, as some of the nicknames given to this species—like "cushion sea star" or "doughboy star"—might otherwise be quite disheartening.

5. Leather Star (Dermasterias imbricata)

This sea star dominates the intertidal zone by consuming a significant share of small prey. However, it faces a formidable threat from the morning sun star, one of its main predators.

6. Morning Sun Star (Solaster dawsoni)

With 8 to 16 arms and countless tube feet, this impressive predator devours mussels, small fish, and even other sea stars, using its appendages to capture and consume its prey.

7. Pacific Blood Star (Henricia leviuscula)

This orange-hued sea star features five slim, elongated arms. Its remarkable ability to regenerate limbs is particularly vital for this species, as it has fewer arms to lose compared to others, significantly enhancing its lifespan.

8. Pink Sea Star (Pisaster brevispinus)

This sizable species can reach up to 2 pounds (0.9 kg) in weight and measure 2 feet (0.6 meters) in diameter. The pink sea star famously inspired Nickelodeon's beloved character Patrick, the starfish who shares adventures with his best friend, Spongebob.

9. Royal Starfish (Astropecten articulates)

Known for its regal deep purple hue and striking orange-edged rays, the royal starfish inhabits rocky North American coastlines. There, it skillfully captures small fish and mollusks, consuming them whole.

10. Sunflower Star (Pycnopodia helianthoides)

This species boasts an impressive number of arms, typically around 24, making it one of the most limb-rich sea stars. It roams the ocean floor at speeds of up to 3.3 feet (1 m) per hour, hunting prey in the chilly Pacific waters stretching from Alaska to California.