What Do Starfish Eat and How? Best Starfish Diets 301 Reveal

What do starfish eat? Feeding Starfish In an Aquarium

Starfish are found in oceans across the globe, together with the Antarctic and the Arctic. But, the Pacific region has the most diverse range.

Globally there are almost 2,000 species. You can find them available in various colors, shapes, and sizes.

These fascinating creatures are completely different from alternative aquatic animals like fish, in the means that they move, eat, and regenerate themselves.

Starfish Fun Fact: Starfish have no bones or brains. They have a lot of other unbelievable features; it includes complex nervous systems. They are able to visualize with their arms (each arm has an eyespot and is too sensitive to light). Again they are also able to expel their stomach. Starfish use the expelled stomach to wrap around their prey and digest it.

This article goes on to look at what starfish eat in the ocean, how they eat, and the way to replicate their diet in a fish tank.

Overview of Starfish

How Do Starfish Eat

Starfish fall under the large category of marine-only animals. These are also called Echinoderms. There are a lot of characteristics of animals within the phylum Echinodermata, and a few of these features are radial symmetry, an absent head, tube feet, and a flat body.

There are around 7,000 species of Echinoderms, which include brittle stars, sea urchins, sand dollar lifestyles, sea cucumbers, crinoids, as well as starfish.

Whilst they are commonly known as starfish, some people are calling for a name change to sea stars (as they are commonly known throughout many European countries).

But the fact is star ‘fish’ do not actually fall under the category of fish. Unlike fish, starfish might live in water, however, at that point all the similarities end.

They do not have scales, fins, and gills. Instead of blood to circulate the nutrients, their bodies use seawater. Again they also use tiny tube feet to move around. Their tiny tube feet sit underneath their bodies.

A few starfish species possess up to 15,000 tube feet and every minute these permit them to make a movement at speeds of two to three meters. It is exceptional and fast for an Echinoderm.

Sea stars belong to the class Asteroidea. This word is derived from the Greek word ‘aster’, which means star, and the word ‘eidos’, which means form, likeness, or appearance.

There are more than 2,000 species of starfish that are available over the clusters. They all are marine animals; meaning they survive alone in the saltwater. They do not live in freshwater.

The majority of the starfish possess 5 radial symmetrical arms (identical arms that grow almost one central point); but there are some species that have 10, 20, and even 40 arms. They are known for their ability to regrow their arms when they have been broken. They can intentionally shed their limbs if they fall in danger, it is called autotomy.

Studies have been made to show them intentionally to get rid of a few of their legs while they have been subjected to extreme temperatures for too long.

Starfish grow up to 4.7 to 9.4 inches. It can also weigh up to 11 lbs depending on the species. They survive anywhere between 5 to 35 years.

What do Starfish Eat in the Ocean?

Linckia laevigata Starfish

Sea Star Feeding: The food that is eaten by starfish very much depends on its species. Some starfish are predators and scavengers and some have the same diet as fish.

The majority of them are carnivorous predators and feed on mollusks such as clams, mussels, and oysters that live on the seafloor. In the wild environment, one single sea star can eat more than 50 little clams every week.

To find and eat Mollusks is relatively easier for starfish. Because Mollusks are slow-moving creatures and are usually attached to rocks and to various surfaces. They are able to consume tiny fish and various other species, detritus, algae, and other decomposed plants.

What Kind of Food does a Starfish Eat?

Starfish sexual reproduction

A list of things given below that starfish typically eat in the wild environment in the ocean:

  • Barnacles
  • Plankton
  • Snails
  • *Coral Polyps
  • Sea urchins
  • Clams
  • *Decomposed organic materials
  • Slow-moving fish
  • *Hermit crabs
  • Mussels
  • *Other starfish
  • Sea snails
  • *Seaweed
  • Oysters

Only a few species can eat this * star-marked thing.

How do Starfish Eat?

How do Starfish Eat

You may be wondering how exactly starfish eat, with no visible or obvious mouth.

As mentioned earlier, they have eye spots on each arm that are sensitive to light, and their mouth and stomach are on the underside of their body. Their most sensitive arms allow them to feel around for food.

How starfish eat depends on how they move. It is because if they do not make any movement they will not be able to travel around in search of food. Here we will take a quick view of how starfish move first in reality.

Under their arms, there are lots of tube-like feet that are solely adapted to unstick and stick to things.

As well as using their arms to move and hold onto rocks etc., they also use them to hold onto their prey and pull shells apart (only a 0.1mm gap is required for them to eat the mollusk).

They have a pair of stomachs. Starfish digest their consumed food in two stomachs; the pyloric stomach and the cardiac stomach respectively.

To eat their food, they will first center their prey using their arms and tubed feet. The starfish can extend its cardiac stomach out of its mouth as the prey becomes close enough. The stomach seems like a cloud while it is extended. After that, they cover their prey with the help of their stomach and digest partially.

If starfish are eating mollusks, to open the shells they use their arms very slightly, then they spit their stomachs into the mollusk shell. After that, the stomach then releases some chemical that dissolves the mussel. Finally, they consume the body of the mollusk.

Starfish can draw the cardiac stomach back into the body when they have consumed their food, where the digestion process of the food continues in their pyloric stomach.

This process permits the starfish to eat things that are much bigger than them, by digesting the larger things outside of its smaller mouth and taking them in once they’ve been transformed to liquid.

Researchers have discovered a molecule that carries signals that trigger the stomach to retract and contract. For both environmental and economic reasons, this type of research is very useful. A few will feed on shellfish which are harvested for the purpose of our food, In the case of large surges in the population, some other species damage parts of the Pacific reef.

Therefore, this research may permit the researchers to chemically regulate starfish feeding in the wild environment.

What do Starfish Eat in Aquariums

What do Starfish Eat?

(Sea Star in an Aquarium)

A lot of attention and care is required by Starfish and they also require a huge tank set up (minimum 100 gallons in size). Too many starfish will starve in tiny fish tanks and there is not enough rock. Always ensure that you choose the right size aquarium.

Always do some research on the species you are getting before buying it. Sometimes fish stores can sell you the wrong species by using incorrect names. Many starfish are voracious carnivores and can very easily eat their way with the invertebrates of the reef aquarium!

As always, to help fish feel comfortable in their environment, and therefore allow them to eat properly without being stressed, it’s vital that you copy their natural environment as well as possible.

Some live in seagrass meadows, rocky shorelines, or sandy, tidal pools; others live in coral reefs. The fish tank must replicate whichever atmosphere your targeted species is used to.

In reality, they are popular in aquariums; but it is not possible to be fed just fish flakes alone, like most of your other aquarium fish.

As I mentioned above, starfish are grazers. They eat food that has fallen to the bottom of your aquarium, which includes pellets, fish flakes, or any other fish food.

A lot of species enjoy a mollusk’s meaty diet, so introducing some mussels or clams in your aquarium is a perfect way to keep your starfish happy.

If they are bought from the pet store or any supermarket, ensure that you rinse them nicely before adding them to your aquarium.

Like other algae eaters, they’ll consume the algae in your tank too as well as frozen shrimps, prawns, and sponges.

Some species accept vegetables such as kale, boiled spinach, and other green vegetables. Do you wanna make your own fish food at home? If yes then make sure they get the best diet possible.

The feeding frequency depends mostly on your species; you can easily able to know this by observing how often they eat.

Typically, these species are required to be fed every 2 to 3 days. It’s very easy to see if the starfish is hungry – introduce a small quantity of food in front of them and they will quickly eat the food if it’s hungry.

If you’re tense about the other fish eating the food before the starfish eat, directly place your starfish on top of the food when you introduce it at the bottom of the aquarium.

Typically, as these species are nocturnal, they can quickly adapt to feeds in the daytime after being exposed to them often.

Do some thorough research on the species before you place it in your aquarium. Some species like Chocolate Chip eat soft corals, and others are not as destructive however they still need a diet that so many hobbyists are unable to deliver.

Starfish sexual reproduction. Asexual Reproduction in Starfish

Here is a short table providing details on what each species of popular aquarium starfish eats.

Common Name



The Chocolate Chip Starfish (Popularly known as Protoreaster nodosus)

What do chocolate chip starfish eat?

Chopped clams, squid, and shrimp. They can eat sponges, soft corals, and also tubeworms.

They cannot be kept together with corals. Their appearance is like chocolate chip biscuits.

Tile Sea Star or Marble Sea Starfish (Fromia monilis)

Include a lot of live rock as they forage for micro-organisms and also detritus.

Main Supplement its diet with flaked food and small pieces of shrimp.

One of the most commonFromiaspecies. It is highly active and also enjoy complex environments. They thrive on live rock.

The Sand Sifting Starfish (Also known as Astropecten polyanthus)

Requires to be directly fed numerous foods on the sand bed, such as urchins, shrimp, and mollusks. It can very quickly clear out detritus and left-over food. They can also starve if not supplemented.

Reef safe and plain beige appearance, however useful in sifting through the sand.

The Linckia Starfish (Linckia laevigata)

Little requirements to be done to supplement the diet when it is placed in the well-managed fish tank.

If it is required to be supplemented, place some tablets, or pieces of clam meat underneath them.

Reef safe. Though these species can grow big, they are comparatively easy to care for. Come to a large range of bright decent colors.

As I have mentioned above, it is necessary to feed the starfish based on the specific species. Their primary diet is based on the food they generally eat in the wild environment, for some, this will be algae, for others, this will be meaty foods.

What Do Starfish Eat In The Ocean

How do Starfish Reproduce?

Development of starfish: Considering the unique look of these invertebrates, it’s quite normal to wonder, ‘‘How do starfish reproduce?’’. Well, in simple terms, there are two basic processes of starfish reproduction, that include:

Starfish Sexual Reproduction

The large variety of starfish species are both male and female. Many starfish species have the ability to change gender as they get older, meaning that a starfish is born with a specific gender that can change when they reach adulthood or old age.

When it comes to the starfish reproduction cycle, a starfish releases gametes (sex cells) through the gonads in its arms. When the eggs are laid, a male starfish will release sperm to fertilize the released eggs. In the case of hermaphrodite starfish species, it is possible that both parts of this process are carried out by the same individual.

After the eggs are released, there are two ways in which the starfish reproduction cycle can take place:

As part of the plankton may be improved by them, where the mother can incubate them and give protection to them covering them with her body.

They might grow by attaching to a rock.

Once the perfect size, their eggs will give way to the larvae, which float or swim in the ocean water. As they grow mature and become adults, their body morphology changes, and they can develop to inhabit the seabed.

Asexual Reproduction in Starfish

Other starfish species usually follow an asexual cycle of reproduction. Some of them do not need the intervention of other individuals, it is because they have both female and male gonads.

Budding is another asexual reproduction method in starfish. It mainly constitutes the generation of an individual. It grows attached to its parent, which separates only when it is fully developed. This method is very common in starfish larvae that live in environments with abundant food.

Starfish fun fact: Millions of eggs can be produced by a female starfish at once, however only a few of these starfish will become adult starfish.


Do starfish eat algae?

Starfish can also consume tiny fish and some species consume decomposed plants, detritus, and algae.

What do sea urchins eat?

Most of the sea urchins are herbivorous animals. They feed on algae found on seabeds. However, some sea urchins are detritivores, which means they eat decaying matter, while other sea urchins are predators and feed on smaller and slower animals.

Can you eat starfish?

Yes, starfish are edible. Its taste is very closely similar to the sea urchins and these are very happily eaten in Chinese restaurants. Also, you will find seastar eating being served on a stick in China’s food markets.

What do you feed aquarium starfish?

Clams, mussels, scallops, and oysters are the favorite prey of many large to medium-sized starfish. Linckias along with Chocolate Chips will especially appreciate these. Tube worms, bristle worms and various types of worms make excellent alternatives. They also love eating snails.

How do you feed starfish in an aquarium?

Grab a chunk of the rock using forceps for aquariums and place it on top of the starfish or set it in front of the starfish. If the size of the piece was not enough and the fish ate it fast and quickly, give another. Feed the fish about once per week to start. The frequency will vary based on the person.

Can starfish survive in an aquarium?

They are able to be kept in captivity. Some, like Linckia multiflora, are more manageable to handle than others, but you need to know their anatomy and their needs to be able to ensure the success you want.

What are the requirements for starfish in the tank?

The tanks they keep should contain rock coral, sand, and that they love to play with and kick in. 6. Some starfish can consume algae, but in general, you should be ready to feed them food that is good for them. Even frozen fish foods such as clams, shrimp, or other meats may not be enough to satisfy their cravings However, you can give them these.

Brief Summary

Sunflower Starfish Pycnopodia Helianthoides

(Sunflower Starfish (Pycnopodia helianthoides)

If you have some experience in keeping fish and looking for an extremely interesting and unique inhabitant for your saltwater aquarium, the starfish could just be for you.

Few species are very difficult to feed, others are quite simple. Ensure that you have researched carefully about the species you want to place in your aquarium to ensure you get some species-specific feeding advice.

Unfortunately, these are very common causes for starfish to die in captivity either because of not surviving the acclimatization, terrible water conditions, or starving to death.

Make sure before you want to include one in your aquarium, ensure that you know exactly how to care for it, how to keep your aquarium clean, and the perfect food to provide it with.

We do have a recommendation. Before getting a starfish, you have to make sure you educate yourself well about its requirements and needs. Starfish is not a fish tank decoration! They need proper care and an appropriate diet to survive.

We do have to emphasize consulting your local aquarium for some great starfish food options.

Which starfish are you thinking of getting? Is there a particular starfish you like the look of? Let me know in the comment section below…


Dibyajyoti Bordoloi is the creator and author of FishCampRehab.com, a third-generation experienced fish keeper and owner of a successful pet breeding farm. He is also a member of the Center for Wildlife Rehabilitation And Conservation (Assam), the Marine Aquarium Societies of North East India, and the Kaziranga Nature Conservancy of Assam.

Leave a Comment