What does a starfish eat?

In this short article, we will answer the question “What does a starfish eat?”, will show you how to feed them in the aquarium and show you how they and share information about their eating habits.

What does a starfish eat?

The kind of starfish determines the answer. Depending on the species and the availability of food, starfish are mostly opportunistic omnivores with a bias toward carnivory. However, some species are experts at predation or plankton filtration. 

Some starfish consume worms, molluscs, crustaceans, and other invertebrate creatures as food. Many different echinoderm species, including sponges, bivalves, crabs, and coral are preyed upon by some carnivorous species.

Scavenger species are those that eat dead fish and invertebrates. Some go farther and are classified as detrital because they rely on microscopic creatures and organic substances found in sediments to thrive. 

How are sea starfishes fed in an aquarium?

Because they are difficult to maintain, very few species are bred in aquariums. The most widely used species of aquarium starfish is the blue, red, or purple Linckia laevigata, which has a very attractive colouring. 

Depending on the species, different aquarium conditions are required for starfish to coexist in perfect harmony with their natural environment. 

Since abrupt changes have a significant negative impact on them, we need to make every effort to replicate as closely as we can in the aquarium the environment where they used to dwell. 

A marine aquarium in good condition for starfish should contain the following characteristics as average values:

  • pH 8.2, 
  • water density between 1020 and 1026, 
  • temperature between 22 and 25 °C.

They are typically fed mussels, bits of fish, or shrimp in aquariums, though they typically adapt well to different diets.

How does a starfish eat?

The starfish has a mouth in the centre of its ventral part, which is visible from below rather than from above. It is encircled by a thick peristomal membrane and is held shut by a muscular sphincter. 

The oesophagus, which connects to the stomach, can be reached through this hole. The most intriguing feature of these crustaceans is the division of their stomach into cardiac and pyloric parts. 

The first is reversible, meaning that the starfish can “regurgitate” out a portion of its digestive system. The prey begins to be digested alive in the aquatic environment as a result of the release of digestive enzymes.

The cardiac stomach returns to its usual place and the food enters the pyloric region once the prey has died and turned into a form of porridge. 

As a result, the starfish can consume live prey without the use of teeth, claws, or poison to subdue its prey. Without a doubt, humans find their feeding strategy weird. Isn’t that amazing?

What are the feeding characteristics of starfish?

The major characteristic of starfish is that, depending on the species, they are made up of a centre disk encircled by five or more limbs. The ocean’s depths are home to starfish. The majority of species spend the day in sand or rock crevices hiding since they are nocturnal. 

According to the gastric anatomy of the species, the diet of the starfish is divided into two groups: 

  • some consume their food, which consists of small particles through the mouth to be traditionally digested, 
  • while others can slow the stomach directly into their prey to carry out the digestion process. 

They can eat coral as well as static prey that is larger than themselves thanks to their external digesting. Some species of starfish have feet that aid in the digging and lifting of oysters. 

After forcing the mollusc to open its valves, which weakens its abductor organ, the cardiac stomach begins the procedure when the opening is only a few microns wide. digestion of the soft tissues of oysters. 

Two stomachs, the cardiac and pyloric stomachs, make up your digestive system. It is easier for the star to eat larger animals like oysters, clams, and fish since the heart leaves the star’s body and digests the food outside. 

The ability of starfish to regenerate is another intriguing quality. A starfish would sprout a replacement arm in its place if it lost one. Another starfish can be created from the lost organ, even if the missing arm contains a portion of the central disk.

What food habits do starfish have?

The type of starfish determines its diet, although all are predators who seize every opportunity to eat invertebrates. 

Some marine stars obtain the majority of their nutrients from suspended phytoplankton, components of the marine substrate, decomposing plant matter, or organic particles. 

Only sponges, plankton, and organic matter suspended in the water are consumed by other species of starfish. Some starfish balance their diets by eating algae, sponges, corals, carrion, and organic waste in addition to meat. 

So, the majority of their diet consists of still or slowly moving prey. It can include molluscs, crabs, echinoderms, worms, various invertebrates, crustaceans, and perhaps even small fish, depending on the species. 

Some starfishes are experts in eating other echinoderms, such as different kinds of starfish.


In this short article, we have answered the question “What does a starfish eat?”, and have shown you how to feed them in the aquarium and shown how they and shared information about their eating habits.


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