Stunning Starfish Facts Explained: How Do Starfish Eat? | Kidadl


Stunning Starfish Facts Explained: How Do Starfish Eat?

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You must have seen a creature on the beach that has a star-shaped body.

It is none other than a starfish, also known as a sea star! A starfish is a mysterious creature that has different ways of living its life and a unique way of eating its food.

Different species of starfish eat different types of food. Starfish eat a variety of foods such as clams and mussels. They do so by extending their stomach out over their prey, digesting it partially externally. Interestingly, then this food is brought back into the digestive glands of the sea star. This helps the sea star to consume organisms that can't fit in its stomach! Keep reading to learn more about the most interesting feeding process in the world!

If you enjoy this article, why not also read about how often to feed fish and when bass spawn here on Kidadl?

How do starfish eat?

The sea star's eating manner wasn't discovered by scientists for many years as its mouth is not clearly visible. They are slow-moving animals that feed upon prey that are also slow-moving. Their prey is typically unable to move away from them instantly or is attached to a rock. Their digestion takes place externally as well as internally with the help of their two stomachs.

A molecule has been identified in sea stars by scientists that allow them to undergo the most fascinating feeding process in the world. A starfish has a mouth and two stomachs present on the ventral side of its body. It also has arms that help it to feel and grab its food. It initiates its feeding process by stretching one of its two stomachs out of its mouth, called the cardiac stomach, over its prey. It feeds upon its prey and digests it externally. The digested prey and the cardiac stomach is brought inside so that the second stomach, called the pyloric stomach, can digest it further. This method to feed helps the starfish eat food that is bigger than its size. Movement is an essential part of its feeding as it helps it find food and capture it.

How and what do starfish eat in aquariums?

What a starfish eat varies with the species of starfish. Sea stars are carnivorous animals that cannot survive only on fish flakes. These predators need a healthy diet that will keep them satisfied. Consulting a local aquarium about the dietary requirement of your starfish species is recommended so as to ensure the well-being of your marine animal. All starfish love to be fed mollusks, clams, and mussels. The mouth of the starfish is present on the underside of its body. To feed the starfish easily, the food must be placed under it or near it so that it can eat easily.

It is quite easy to determine if a starfish is hungry. If the starfish eats the food in a short span of time after you have placed food near it or under it, it means that the starfish was quite hungry. To feed a starfish, food can be kept near it, but if there are other organisms present in the aquarium as well, the starfish can be placed over the food so as to ensure that the food is eaten by the starfish only. A starfish is a nocturnal animal that has the ability to adapt to a diurnal feeding schedule as well. It needs to be fed once every two or three days. The feeding frequency can be determined by keeping food close to the starfish at intervals. If it devours it instantly, then it means that the sea star was hungry. The feeding schedule varies from sea star to sea star and must be kept accordingly so as to avoid the pet sea star becoming famished. It is essential for a starfish owner to research its species extensively to be educated on necessities of the starfish. It is also important to research a starfish species as some species are known to eat organisms such as corals that are also kept in an aquarium. A starfish needs a well-balanced diet and appropriate care to thrive in an aquarium setting. The diet of a pet starfish is different from a starfish in the wild; thus, it must be fed healthy food once every two or three days. It is not recommended for beginners to keep starfish as a pet as they need an advanced level of care.

Many cushion starfish underwater on a sandy ocean floor

How and what do starfish eat in the ocean?

Starfish are carnivorous predators that hunt on their own. Their primary food in the ocean consists of small fish, sea urchins, crustaceans, snails, mussels, clams, plankton, coral polyps, sea cucumbers, and anemones. These organisms have one thing in common: they are slow-moving and can be easily ingested by starfish due to the weak mobility of these organisms. Starfish are defenseless, white-bodied invertebrates that can consume a wide range of prey. These marine animals do so by expelling their stomach out to catch prey and decomposing it with their digestive juices. They pull their stomach back inside their body to swallow the decomposed prey.

There are some starfish species that only feed upon decaying animal and plant matter in the ocean. The majority of starfish species are carnivorous and eat mollusks such as oysters and clams. A sea star in the wild has the ability to eat more than 50 clams within seven days. Similar to fish species, different starfish species have different diets. Some starfish are predators, whereas some are scavengers. Chocolate chip starfish eat sponges, clams, soft corals, squid, tubeworms, and shrimp. A crow of thorn starfish dines upon corals such as staghorn corals that are fast-growing. Pacific blood starfish eat sponges, bacteria, and plankton. A sunflower sea star dines upon sand dollars, crustaceans, clams, sea cucumbers, gastropods, fish, and sea urchins. Leather starfish eat anemones, sponges, sea cucumbers, fish eggs, sea urchins, hydroids, and chitons. Marble sea stars eat micro-organisms and detritus from live rock. Egyptian sea stars that can be seen dwelling in coastal waters and coral reefs eat snails, algae, and sponges. A sand-sifting starfish feeds upon foods like urchins, mollusks, and shrimp. They eat food directly from the sand bed and are known to clear out detritus instantly. Other foods that starfish eat and that are a part of the diet of many are decomposed organic material, hermit crabs, barnacles, oysters, coral polyps, sea snails, other species of starfish, plankton, gastropods, sand dollars, fish eggs, crustaceans, chitons, hydroids, sponges, squid, sea cucumbers, tubeworms, bacteria, anemones, shrimp, slow-moving fish, seaweed, algae, and sea urchins.

Do starfish have teeth?

No, starfish species do not possess any teeth. They do possess a mouth that is present on their body's flattened part in the middle. A starfish does break down its food before swallowing, but the stomach performs this function rather than teeth. The cardiac stomach of these marine animals stretches out of their mouth, onto their prey, and starts to decompose it, breaking it down so that it is easy to swallow.

Starfish have no blood or brain present in their body! Starfish utilize seawater to transport nutrients throughout their bodies instead of blood. They have a water vascular system that circulates nutrients in their body. Starfish also don't have any fins, gills, or scales present on their body. They use their small tube feet for locomotion. These small tube feet are present on their body's ventral side. These tube feet are present in large numbers, approximately 15,000, and help the starfish to move as fast as 9 ft/min (2.7 m/min). The skin of starfish is made up of calcium and has a hard, grainy, rough texture. Some species may have a smooth texture though. Starfish can be brightly colored such as white, blue, and red and can also be neutral toned. A starfish's neutral tones help the starfish to camouflage effectively and dodge predators. Starfish do have eyes that are not easily visible. The starfish's eyes are quite unique and very different from eyes of humans. They are also known as eyespots and serve as some sort of light detector for the starfish. The eyes are present at the arms' ends.

Did You Know...

A starfish is an animal that is a member of the Echinodermata phylum of creatures. Echinodermata is a vast group of marine animals that have symmetrical limbs encircling a single point present at the center, have a flat body and tube feet and the head is absent.

Most starfish species possess five radial arms, but some species can have 40 arms as well! These arms have the ability to regrow if they get damaged and even have the ability to be shed if trapped.

Sea stars belong to the class Asteroidea.

'Asteroidea' is a term that originates from Greek terms that translate to 'aster' and 'form' as asteroids look similar to aster flowers.

The class of echinoderms consists of approximately 7,000 species comprising sea urchins, sand dollars, sea stars/starfish, brittle stars, sea cucumbers, and crinoids. These organisms are not fish and are quite different from fish.

The Pacific blood starfish is also commonly referred to as the blood star.

Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for how do starfish eat then why not take a look at how many teeth do sharks have, or Starfish facts!

Written By
Rhea Nischal

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