21 Interesting StarFish Facts: You Need to Know

Sea stars or starfish are star-shaped echinoderms that belong to the class Asteroidea. Hence, these creatures are also known as asteroids. It is a fascinating creature that can be seen in oceans worldwide. These creatures can be distinguished by their star-like shape.

About 1900 species of starfish can be found on the seabed in all types of oceans, from frigid, polar regions to warm, tropical zones.

Sea stars can be seen from intertidal places to abyssal depths. So, in this article, we will explore some really amazing facts about this amazing sea creature called Starfish or Sea Star.

Facts About Starfish:

They are diverse animals:

There are more than 2000 species of starfish. Each of them has its own unique characteristics. They come in various sizes, shapes, and colors, from delicate, small species measuring less than an inch across to large, imposing species growing up to three feet in diameter. 

They are marine invertebrates:

Starfish have a unique anatomy that sets them apart from other creatures in the sea. These creatures are marine invertebrates.

They usually have five or more arms that radiate from a central disc. This disc mainly contains the digestive system of the starfish.

They Have tube feet:

Their arms contain hundreds of very small tube feet used for feeding, locomotion, and even respiration. Starfish also have a tough exoskeleton, known as the test, which protects their internal organs.

This creature’s upper or aboral surface may be spiny, granular, or even smooth and is covered with overlapping plates. Many species have attractive colors like blue, grey, brown, orange, or red.

They are opportunistic feeders:

The starfish has tube feet that are operated by a specific hydraulic system. Also, they have a mouth located at the center of the lower or oral surface. These fascinating creatures are opportunistic feeders and are generally predators of benthic invertebrates.

Though these creatures don’t have a heart and blood, they have a brain. Although starfish live underwater, they are not fish because they do not have gills, fins, or scales like fishes do. 

They are carnivorous:

Starfish are carnivorous creatures. They feed on different small sea creatures, such as clams, coral, oysters, sand dollars, algae, mussels, sponges, and other echinoderms.

Also, some species of starfish eat injured fish in the sea if possible. Some species of starfish also feed on dead animals, meaning they are scavengers.

They eat in a unique way:

Though starfish have a mouth at the center of their lower surface, it uses their feet to eat. Its feet have suction cups on the bottom, which helps to hold on to the meal.

It uses its feet to open it up when feeding on an oyster or a clam. After it is opened, the starfish’s stomach goes out of its mouth and then pushes itself inside the clam or mussel shell.

They have unique habitats:

Starfish can be seen in almost every ocean in the world, from the polar regions to the tropics. They live in various habitats, including rocky shores, coral reefs, deep-sea trenches, and even sandy bottoms. 

Some species of starfish even live in freshwater streams and rivers. You can even keep a starfish in a saltwater aquarium.

They have the ability to regenerate body parts:

Starfish have an amazing capability to regenerate their lost limbs. If a starfish loses an arm, it can easily grow a new one to replace it. Hence, they can “sacrifice” their limbs as a defense mechanism.

In some species, the lost arm can even grow into a whole new starfish. This ability is thought to be because of the decentralized nervous system of the starfish, which enables each arm to function independently.

Their fertilization takes place in the water:

Starfish can reproduce both asexually and sexually. In the procedure of sexual reproduction, starfish can reproduce with females and males releasing their gametes into the water, where fertilization occurs. 

Some species of starfish are hermaphrodites, meaning they have both female and male reproductive organs. After fertilization, the eggs hatch into free-swimming larvae.

This eventually settles on the ocean floor and then grows into adult starfish. Moreover, asexual reproduction in starfish occurs through autotomy of arms or by fission.

They can communicate through chemical signals:

Starfish can communicate with each other with the help of chemical signals. Generally, they release pheromones into the water, attracting other starfish to potential mates or food sources.

This chemical communication is also thought to play a vital role in social behavior, such as dispersal and aggregation.

They can live around 35 years and can feel pain:

The average lifespan of a sea star or starfish is around 35 years. Although generally, the bigger species can live longer than their smaller counterparts.

In addition to this, although starfish don’t have hearts, blood, and brains, they can still get hurt or feel pain because they have complex nervous systems.

Some species of starfish can even go out of the water for several hours without any harm. Moreover, some larger species of starfish can even survive out of the water for almost 28 hours.

They are usually edible:

There are a variety of opinions regarding the taste of starfish. Some argue that it tastes like sea urchins or river crabs, while others say it tastes nothing.

Delicious starfish items are sometimes served in several sushi restaurants or even on the streets in Beijing, China.

Their defense mechanism:

Starfish have different methods to defend themselves against predators. Some species have spines or even toxic chemicals in their skin that can deter a predator. In contrast, some can detach their arms to distract their predator and make a quick escape.

Sometimes, the starfish’s hard covering may feel thorny or leathery. This outer skin is made of calcium carbonate with little spikes. This protects them from predators like birds, sea otters, and fish.

Their role in ecosystems:

Starfish play a vital role in marine ecosystems as prey and predator. They help control populations of various other animals, such as crustaceans and mollusks, and are a vital food source for larger predators, such as sea birds and fish.

In addition to this, some species of starfish are vital habitat builders, creating complex structures on the sea floor that offer shelter for a variety of other ocean organisms.

Some Of Them Are Bioluminescent:

Though most species of starfish are not bioluminescent, some of the deep-sea species still have the ability to create light. This is considered to be a form of communication, as well as a method to confuse predators or to attract prey.

They also have eyes. Their eyes are located on the tip of their arms. Each of their arms has an eye that appears as a red spot. Though their eyes cannot see anything clearly, they can sense light and dark, which suits their environment.

They Can Work As An Indicator Of Ecosystem Health:

Due to their vital role in marine ecosystems, starfish are regarded as one of the indicators of ecosystem health. Changes in the starfish population can signal changes in pollution levels, shifts in the food web, or various other environmental factors.

This makes starfish a crucial species for monitoring and conservation efforts.

Starfish Have Been Used In Traditional Medicine:

Starfish have a long history of importance and use in traditional medicine. In China, dried starfish are used to treat different types of ailments, such as back pain and arthritis.

Moreover, in some Pacific Island cultures, starfish are used to treat various infections and skin diseases.

Starfish Are Vital To Scientific Research:

Starfish have been the subject of extensive scientific research due to their role in marine ecosystems and unique anatomy.

Scientists have studied and researched starfish communication, regeneration, behavior, and their response to various environmental stressors, such as climate change and pollution.

This research has helped to light up many aspects of marine biology and has the potential to inform various conservation efforts for starfish and many other marine species.

Starfish Have Inspired Culture And Art:

For a long period of time, starfish have been a vital source of inspiration for writers and artists. They have appeared in literature, mythology, and also art throughout history.

In those places, starfish are often used as a symbol of resilience, regeneration, and also renewal. In modern times, starfish inspires many artists, from tattoo artists to jewelry designers.

Their largest starfish:

The largest starfish, known as the sunflower starfish, lives in the Northeast Pacific Ocean. Their arms can reach about a length of 1 meter. Also, they have 16 to 24 arms that have powerful suckers.

This sunflower starfish has many colors, like yellow, orange, brown, red, or even purple. They usually feed on sea urchins, snails, clams, etc.

There are other famous starfish, such as the Royal, Bat, and Nine-armed starfish. You can also get to see the most uncommon species of starfish, the Square starfish, in Matheson Bay, New Zealand.

They Are Threatened:

Despite their resilience, starfish face different threats. They are even threatened by climate change, pollution, and habitat destruction. Some of them are even collected for the aquarium trade. So, starfish are interesting sea creatures with many amazing qualities and unique anatomy. At

The end of this article, we learned about 21 amazing facts about this fascinating sea creature.  These facts offer us a clear picture of this significant creature of our ecosystem. To know more, you may visit our website.

starfish infographic

Interesting Takeaways:

  1. Starfish, also known as sea stars, are not fish but echinoderms that have the ability to regenerate lost limbs.
  2. There are over 2,000 species of starfish found in oceans all over the world.
  3. Starfish play a vital role in maintaining the health of coral reefs and other marine ecosystems.
  4. Despite their important ecological role, many species of starfish are threatened by pollution, overfishing, and climate change.
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