Starfish are invertebrates that live in the ocean and have a five-pointed radial symmetry. They are a very peculiar species. They don’t have a brain and their mouth is extremely small. Which makes the question of what they eat even more fascinating.
They have a special way to get their food. They can reach it with a very sticky arm that lets them hold on tight, and then they use venom in order to kill the prey, which makes it easier for them to eat it.
Their stomach is designed to help them digest food before it gets in.
In this article, we are going to see what starfishes eat, but most importantly how, since it affects their eating patterns more than anything else. When you’re built a certain way, you are forced to eat only certain types of food.
Starfish Diet 101
Starfish might look innocuous. They come in many color patterns and look very cool. But they are actually dangerous predators.
They have an arm that they can shoot out and attach to their prey, then inject venom to kill it. Once the prey is dead, they use their stomach acid to digest it before eating it. This makes their eating process slow, but they can eat things that other predators can’t because of their toxins.
They don’t have a brain, so they can’t really think about what they’re going to eat. Their mouth is small because their diet comprises sessile animals, with a few exceptions.
They eat a variety of prey, including mollusks and crustaceans. Different species have different types of toxins in their venom, which makes the element more unique by each starfish’s characteristics. The process of catching to eating is slow, but once they find food, it’s hard for them to let go.
Starfish Main Sources of Sustenance
Starfish diet consists mainly of mollusks, but they also eat crustaceans and echinoderms.
- Mollusks are a type of soft-bodied invertebrate that have a muscular foot, which they use to cling onto things. They can be found in both salt water and freshwater habitats, and come in a wide range of shapes and sizes.
- Crustaceans are part of the arthropod family, so they have exoskeletons and jointed legs. Starfish only eat sea crustaceans, but there are some species that will also eat freshwater ones too. Crustaceans include crabs, lobster, crayfish, etc.
- Echinoderms are marine animals that live in salt water. They have radial symmetry and they also possess a unique hydraulic system, with its own set of muscles, which lets them move quickly for their size.
Starfish will usually eat whatever they can find at low tide on the beach or just below the surface of the sand. They have an excellent sense of smell, so they can easily find their prey.
But because they don’t have a brain, they cannot store food and they have to eat it as soon as they catch it. Which is why starfish are usually only seen during low tide.
Starfish also scavenge for food that has died and sunken to the sea floor. This includes fish that have died of natural causes, or other animals that were killed by predators and then sunk to the bottom of the ocean.
Do Starfish Eat Coral?
There is some debate over whether starfish eat coral. Some people say that they do, while others say that they don’t. The reason for the disagreement is that there are different starfish, and some of them eat coral while others don’t.
Specifically, the Crown of Thorn Starfish found in the Indo-Pacific region are corallivores. This means that they only eat coral. Other types of starfish, such as the Crown-of-Thorns Starfish found in Australia’s Great Barrier Reef area, are not corallivores.
This makes them dangerous for our environments, as corals are vital to the ocean habitats. Corals are very important because they provide shelter for many types of fish.
They also help to maintain the health of coral reefs, which are crucial to marine life and humans who rely on these habitats today. The Crown-of-Thorns Starfish feeds by extracting tissue from living coral polyps using their tube feet with venomous spines. This can cause a lot of damage to the coral and it can take years for it to recover.
Do Starfish Eat Algae?
Starfish rarely eat algae, but there are a few species that do. The reason starfish rarely eat algae is because it’s not very nutritious as it doesn’t have a lot of protein in it.
But some species of starfish have been known to eat micro-algae, which is a type of algae that is tiny. This type of algae is usually found in the water column, and starfish can get it by filter feeding.
Filter feeding is when they open their mouths wide and suck in water, which then passes through their gills. The micro-algae will get trapped in the gills, and the starfish will eat it.
What and How do They Eat: Variations in Diet in Different Starfish Species
Different starfish have different diets. Some species will eat a lot of one type of food, while others can be quite diverse in what they eat.
There are thousands of different starfish species. We made a small list to show you the coolest looking ones, and the ones you are most likely to find lying on a beach.
As the name suggests, the common starfish is the most common type of starfish. It’s found all over the world in both salt water and freshwater habitats. It looks very similar to most other types of starfish, and it has a very wide range of prey.
This includes mussels, clams, oysters and barnacles which they eat by puncturing the shells with their tube feet. They also catch shrimp, fish larvae and small crustaceans with these feet as well.
he Crown-of-Thorns Starfish is one of the most dangerous starfish in the world. They are found mostly in Australia’s Great Barrier Reef or Indo-Pacific region.
Crown-of-Thorns Starfish eat coral. They usually feed on branching corals, which are hard and have many nooks and crannies for the starfishes’ tube feet to hold on to while they’re eating it.
The crown of thorns starfish has about 150 spines on its surface, which it uses to puncture coral polyps and extract tissue for food. When these spines break off, they cause a lot of damage to coral reefs.
The brittle starfish is a type of sea star that can be found in both salt water and fresh water habitats.
It has a very brittle skeleton (hence its name) that is made up of calcium carbonate, and it’s covered in spines. It usually has five arms, but there are some species that have more or less.
Its diet includes small fish, shrimp, crabs and other invertebrates. It catches its prey by extending its arms out towards them and then gripping them with its tube feet. It then pulls them into its mouth and eats them.
The sea urchin is a type of echinoderm that lives in the ocean. They can be found in both salt water and freshwater habitats, but they prefer salt water.
Sea urchins have a sharp spiny shell which they use to protect themselves from predators. They also have tube feet, which can move them along the sea floor and bring food towards their mouths.
Their diet comprises algae, invertebrates like clams and mussels, dead fish and other organic matter that floats in the water column.
Sunflower starfish look like sunflowers. Shocking, I know. They are the biggest starfish species, as they can grow up to over a meter in diameter.
They eat animals like sea cucumbers and scallops, which they catch by using their tube feet. They also prey on snails and molluscs, such as clams and oysters. One sunflower starfish can eat up to six of these per day!
The Sunflower Starfish is one of the few species of starfish that can eat coral.
Spiny starfish are found around the UK, Canary Islands and Mediterranean.
The spiny starfish is usually brown in colour with large spikes on their surface to help protect themselves from predators. They have white spots near where their mouth is located, but they can also be speckled with other colours too.
The Spiny Starfish is another example of a species that has a diverse diet. It will often feed on oysters, clams and mussels which they catch by using their tube feet. These tube feet are filled with poison that stuns the prey first before pulling them into the starfish’s mouth for eating.
Spiny Starfish are one of two types of sea stars that can eat coral, but this only happens when there isn’t anything easier available to eat nearby!
Starfish: Predators and Prey
Because starfish are slow-moving animals, they have a lot of predators. Some of their predators include seagulls, crabs, fish, octopuses, etc.
But the biggest predator of all is man. This is because we harvest them for food, as well as for their shells and other parts of their body.
Starfish also have predators that eat them, such as the Sun Starfish. This is a type of starfish that lives in the Pacific Ocean. It preys on smaller starfish, as well as mollusks and echinoderms.
The Sun Starfish has powerful jaws that can easily crush the shells of its prey. It also has a toxic venom that it uses to kill its victims.
Starfish Hunting: The Process and Venom
The entire process of hunting is very slow, but once they find their prey, it’s hard for them to let go. Once the starfish finds its prey, venomous barbs on each arm inject a toxin that paralyzes or kills small fish and other marine life like urchins.
It then uses its stomach to suck out the innards and turn them into a soup which it can digest. It also has very sharp eyesight, which helps in finding prey like urchins hiding in their holes.
The starfish then attaches itself onto the top of its victim with its tube feet and uses enzymes from mucus-secreting cells on its body to digest the prey alive. This process can take up to several days, during which the starfish will not move from its spot.
The venom is very potent and it can cause a lot of pain if it comes into contact with human skin. In fact, in some cases, it can be deadly. So, if you ever see a starfish on the beach, it’s best to leave it alone.
But you might wonder: how do these things move? They look innocuous on beaches. Starfish can move quickly for their size by using the water pressure in their hydraulic system. This system comprises a series of muscles that run the length of their body and can be controlled independently. When they want to hurry, they use this hydraulic system to suck in water and then squirt it out again, which makes them move forward. Therefore they can move so easily across the sand.
Here’s how it looks like:
It’s fascinating. They have thousands of tiny limbs on their underside that they use to move.
Starfish can regenerate lost limbs, so if you step on one, don’t worry too much—it will probably be okay.
Are Starfish Dangerous to Humans?
Starfish are not dangerous to humans. They have powerful venom, but they can only use it if their prey is touching one of the thousands of tiny spines on their arms.
Their toxins will kill a human fast enough, but there aren’t many cases where this has happened. The most common injuries starfish cause to people are because of the spines on their arms.
When we troll the beach and touch starfish, they often contract their muscles to make themselves look bigger than they actually are. This causes many of them to jab people’s feet with their sharp spines, which can cause a lot of pain if it punctures the skin.
The good news is that these types of injuries are not life-threatening. They usually only cause a lot of pain and bleeding, but there isn’t any lasting damage from them either.
Starfish are dangerous predators to other marine life and have the potential to be dangerous to us if we don’t pay attention. They have very strong venom which can kill prey quickly and their spines on the arms also cause pain if it pierces human skin.
But in general, starfish are safe for people to be around because they only attack when provoked or while hunting. They are very interesting creatures we find fascinating because of their varied color patterns.
Starfish have a variety of diet options, including smaller starfish, mollusks, and echinoderms. When the prey is touched by a sunfish’s arms, it has thousands of tiny spines that inject venom into their victim. Alternatively, if this does not work, and the prey lives through the attack, the starfish uses its mouth to suck out all of its innards before digesting them as food.