What Do Starfish Eat?

what do starfish eat

Many starfish species sold as pet fish are omnivorous scavengers; however, some species can also act as predators of coral polyps and fish!

Starfish probe their prey with their arms before enveloping it in their bodies. Once inside, their stomachs protrude through their mouths to release acid that dissolves the inedible shells and operculum before pulling back any dissolvable food into their bodies for digestion.

Algae and Detritus

Starfish are multi-part invertebrates that are prevalent throughout marine saltwater environments, typically inhabiting sandy sea floors, rocky shores, kelp forests and even deeper ocean depths. Starfish have evolved to live in numerous habitats and feed on various forms of aquatic organisms found throughout their environments such as algae, detritus (dead organic material), snails or bristleworms; waste from other tank occupants may even provide food sources.

As scavengers, they play an essential role in maintaining a balanced ecosystem in an aquarium. In their natural environments, these predatory organisms feed on mussels, oysters, clams and sand dollars among other benthic invertebrates; preying upon coral polyps, marine snails, sea cucumbers and sea urchins as well as various fish species and coral polyps.

Aquarium life offers fascinating observations. When starfish spot edible food sources, their arms extend out into the currents like fans to capture it. When swallowing any shelled mollusks they consume using stomach eversion, their cardiac stomach secretes enzymes to break it down before passing it along for digestion in their pyloric stomachs.

Apart from algae, sea stars feed on other things as well. In particular, corallivores such as crown-of-thorns starfish may prey upon live hard or soft corals on coral reefs – something algae cannot do!

Home aquarists would do well to offer starfish some type of mollusk food such as frozen clam or oyster slurry, fresh cockle shells and/or mussel meat or brine shrimp as this will add essential proteins and nutrition into their diet and likely make for more enjoyable feeding sessions than just scraping leftover food from their tank.


Starfish may appear benign, but they play an essential part in ocean ecosystem. Scavengers as well, they play an invaluable role in clearing away dead animals that sink to the bottom.

Sea cucumbers provide food sources for many other sea creatures in their environment, including marine life such as clams, mussels, barnacles, bristleworms and coral polyps as well as crustaceans like hermit crabs, shrimp, lobsters and small crabs.

Some starfish species are suspension feeders, sucking up food particles as they pass over. Others are cnidarians that eat algae or decomposing marine organisms for sustenance; and still others are omnivorous, feeding on various sources including other starfish species.

Starfish move around quickly across the ocean floor to search for food. Their tube feet, attached at each arm’s tip, allow them to scoot along quickly from one place to the next allowing the starfish to move rapidly between different environments.

Starfish use their arms to seize food by pulling on it with their arms; this process, known as eversion, allows them to pry open its shell before inserting their stomachs inside it for consumption.

As well as using eversion, some starfish also pierce their prey’s skin in order to extract fluids from within its body and then use its digestive system to break down meat and organs.

Most starfish possess natural defense mechanisms to ward off potential predators. They may spray slime, release harmful chemicals or use their spines to deter larger fish that might try to consume them. Furthermore, many sea stars possess unique regeneration capabilities which make them valuable marine invertebrates.

Snails and Clams

Starfish in the wild feed on a wide array of marine life, from shellfish like mussels, clams and oysters, crustaceans such as shrimp and crabs as well as worms snails and sea cucumbers, to organic material from sources like waste disposal sites. Their varied diet allows them to obtain essential vitamins from multiple sources.

Starfish have evolved an unusual feeding mechanism that makes use of the small opening at the base of all their arms to capture and digest large prey, but such tiny openings would seem incapable of doing this alone. But starfish have created an alternative feeding strategy.

Most starfish are suspension feeders; their lower parts of their arms feature cilia that capture small food particles and channel them towards their mouths. Others are active predators that use tube feet to grasp prey before everting their stomachs to release digestive enzymes into their crack between outer and inner shells and absorb its flesh while discarding indigestible shell.

Some species of starfish such as Pisaster oculatus corallivorous crown-of-thorns starfish require specific diets that may be hard to replicate in an aquarium setting, while most seen for sale as pets can thrive with generalized feeds.

To recreate their natural diets, offer your starfish foods such as clams, mussels and oysters. Add a small serving of kale, spinach or lettuce as well; just be sure to cook it first!

Baby starfish are too weak to hunt for food themselves and must instead consume microorganisms and other microscopic organisms as food sources. Some studies indicate they also feed on mud to absorb organic molecules from it.


As with other sea creatures, starfish are carnivorous predators and feed on an assortment of prey items depending on their species, environment and availability in their area. Prey items usually consumed include clams, mussels, oysters snails sea urchins crabs shrimp as well as coral polyps kelp algae detritus as dietary staples.

Starfish use their arms to form feeding fans that capture prey, then position their mouth so it can best swallow it. When they have found their target, they move their mouth to where it can best swallow it before taking advantage of their unique anatomy to devour even larger prey items than could fit into its small mouth through something called stomach eversion; moving jaws quickly forward before using their cardiac stomach (secretes enzymes to break down food item before passing it off to their pyloric stomach to be digested further).

Starfish that wish to feed on hard shell mollusks employ their tube feet to overpower the muscle that keeps their shell closed, then use their claws to break through and begin eating their interior. Although it might take time, starfish have no difficulty cracking open and devouring even large clams, mussels or oysters!

If you have a starfish in your aquarium, take care to feed it only freshwater fish species such as Paralithodes camtschaticus red king crab. Certain fish species have been known to prey upon starfish and kill them quickly, so make sure that you consult either your tank care manual or inquire at local pet stores about which foods may be harmful for its survival. Likewise, ensure the age of water in your tank allows it to support this delicate animal before adding one into it.

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