Octopuses are carnivores. They eat crustaceans, mollusks, and small fish. Hatchlings eat copepods, larvae, and plankton, while juvenile octopuses eat progressively bigger prey. Captive octopuses should be fed seafood they’d encounter in the wild. They are ambush predators who catch their prey with their arms.
As gentle and cautious as they might be, octopuses do need to hunt and kill. When it comes to eating, they change from noble creatures to ruthless, cunning predators.
But what do octopuses eat? What is the difference between octopus species’ diets? And how do they hunt?
In this article, we answer every question regarding octopuses’ diet. We look at what they eat, when they eat, and how they get their food.
What Do Octopuses Eat?
As carnivores, octopuses eat meat exclusively. Their diet includes smaller creatures than them. The three main octopus prey are crustaceans, mollusks, and small fish. Opportunistic octopuses rarely feed on birds and turtles.
The exclusively meat-eating octopuses have an abundance of prey in their natural habitat. They live anywhere from shallow tropical waters to cold deep waters. Deep waters are rich in small marine creatures (the main food source of octopuses).
Octopuses generally hunt animals that are much smaller than themselves. They also steer away from creatures with natural defenses but attack animals with shells and exoskeletons.
Octopus diet includes three main prey groups and an additional one:[1]
- Crustaceans
- Mollusks
- Small fish
- Marginal prey
1. Crustaceans
Crustaceans are among the main food items of octopuses. The main characteristic of these animals is their hardened exoskeleton. These exoskeletons (shells) can easily be broken by octopuses’ beaks.
Crustaceans are relatively slow-moving creatures, so octopuses generally have no hard time catching them.
The following crustaceans are eaten by octopuses:
- Crabs
- Lobsters
- Shrimp
- Barnacles
2. Mollusks
Although octopuses are mollusks themselves, they do not shy away from eating them. The largest octopus species are among the biggest mollusks, so they can easily catch and overpower their smaller relatives.
Octopuses eat the following mollusks:
- Snails
- Sea snails
- Bivalves
- Cephalopods
3. Small fish
Fish are trickier to catch, as they are slippery, flexible, and fast. Octopuses often opt to pounce on unsuspecting fish to catch them off guard. When fish are caught and get bitten by octopuses, there’s only a small chance they escape.
Although hunting them needs more calculation and effort, research shows that octopuses prefer fish to all other food items, when given the choice. They only prefer to hunt crustaceans and mollusks because they are easier to catch.
Here are some fish species octopuses eat:
- Anchovies
- Clownfish
- Cardinal fish
- Dottybacks
- Small sharks
Small sharks are prey for big octopuses which have the strength to kill them.
4. Marginal Prey
Apart from the main prey, octopuses hunt other small animals if the opportunity arises. As they eat anything they can catch, they do not shy away from any smaller animal that’s within their grasp.[3]
Here are some animals octopuses may catch and eat:
- Newborn turtles
- Storm petrels
- Terns
- Little gulls
- Sea snakes
Octopus Diet Based on Species
The more than 300 octopus species that vary in range, size, and diet. Smaller species will prefer baby fishes and copepods, while large individuals can attack smaller sharks.
What octopuses eat greatly depends on their size. As they hunt anything smaller than them, minute octopuses do not attack grown crabs as bigger octopuses would. Their diet naturally depends on their range as well.
The table below compares what the largest (giant Pacific octopus[4]), smallest (star-sucking pygmy octopus[5]), and most common octopus species eat.
| Species | Diet |
| Giant Pacific Octopus | Clams, cockles, scallops, abalone, small sharks, lobster, crabs, cephalopods, arctic char, Bering flounder, variegated snailfish |
| Star-Sucking Pygmy Octopus | Copepods, plankton, small mollusks, larvae, fish eggs |
| Common Octopus | Clam, shrimps, small crabs, small lobsters, anchovies, queen angelfish, red porgy |
What Do Octopuses Eat in Captivity?
Captive octopuses need the same food items they would find in the wild. Live food is preferred, but frozen shrimps are acceptable alternatives when feeding octopuses.
Octopuses should exclusively be fed meat, as they are carnivores. Live animals, like mollusks, are the best food source for captive octopuses. But they eat any meat-based nourishment or food of animal origin (like eggs).
Feeding can be supplemented with thawed frozen fish. Most octopus keepers feed their pets frozen shrimp a majority of the time. Apart from this, anchovies are among the favorite food items of octopuses.[7]
Captive octopuses can be fed the following animals:
- Frozen shrimp
- Anchovies
- Live mollusks
- Live crabs
- Live lobsters
- Animal-based products
What Do Baby Octopuses Eat?
Young octopuses go through drastic changes while they grow, so they need specific food to consume. Hatchlings eat plankton, other larvae, copepods, and each other, while juvenile octopuses eat progressively bigger and bigger animals.
Octopuses go through four life stages: egg, larva, juvenile, and adult. They start feeding after the eggs hatch in the larval stage. Juvenile octopuses progress toward the adult diet, eating larger and larger animals as they grow.[8]
| Life Stage | Diet |
| Larval | Copepods, larvae, plankton, each other |
| Juvenile | At the beginning they eat larvae, fish eggs, and copepods, at the end they move to a regular diet (crabs, clams, fish) |
What Do Octopus Larvae Eat?
During the larval stage, octopuses are less-than-an-inch-long paralarvae swimming on the surface of the ocean. They mostly encounter plankton and other larvae there. Hatchlings also feed on each other, until they develop enough.
After a period lasting up to a few months, octopuses submerge and swim down to the bottom.
What Do Juvenile Octopuses Eat?
Juvenile octopuses’ body weight increases by five percent each day. They constantly feed, progressing to bigger food as they grow.
In the beginning, they feed on the same food as they ate in the larval stage (copepods, lobster larvae, and starfish larvae). As they progress in size, juvenile octopuses start hunting and eating larger animals, introducing small fish and mollusks to their diet.
By the end of the juvenile stage (a few months to two years), the octopus is considered an adult and eats its normal diet.
How Do Octopuses Hunt?
Octopuses are opportunistic and pouncing predators. They seek smaller animals out and pick them apart with their beaks. Faster fishes are caught by pouncing and injecting venom.
Octopuses hunt a variety of prey, so they have to adapt to every hunting situation. They are either methodical seekers or pouncing ambush predators, depending on what animal they are after.
The two types of hunting methods are used in two situations:
- Hunting slow prey
- Hunting fast prey
1. Hunting Slow Prey
Octopuses are intelligent animals, so they prefer to hunt for prey that is unlikely to fight back. Crustaceans and snails are slow-moving animals that are easy to catch.
When hunting slow-moving animals, the main brain of the octopus sends a “seek food” signal to the mini-brains of the arm. After the prey is found, the arms reach out and raise it to the beak of the octopus.
If the target is shelled, the octopus scrapes the meat out with its toothed tongue-like organ called radula after it breaks it with its powerful beak.
2. Hunting Fast Prey
If octopuses decide to hunt fast animals (like fish), they opt to remain stationary and wait. They are helped by their camouflage. Octopuses’ skins are able to change color to blend in with the surroundings.
When an unsuspecting animal gets near the octopus, it gets pounced upon. It will naturally struggle, so they are paralyzed by the octopus’ octopus’ venom found in its saliva. The paralyzed prey is helpless and the octopus returns to its den with a hassle-free meal.
How Much Do Octopuses Eat?
Octopuses can eat up to four percent of their body weight. Although most octopuses hunt every day, some species only need to eat about every four days.
As each octopus has a different size, there is no exact amount of food they eat. Instead, they eat between two and four percent of their body weight.
Some octopus species do not need to eat each day. Octopus mothers that are brooding their eggs can live for months without feeding. They die around the time their eggs hatch due to starvation.
| Species | Body Weight | Food Intake/Day |
| Giant Pacific octopus | 110 pounds | 2.2–4.4 pounds |
| Common octopus | 22 pounds | 0.44–0.88 pounds |
| Mimic octopus | 20 pounds | 0.4–0.8 pounds |
| Caribbean reef octopus | 3.3 pounds | 0.066–0.132 pounds |
Conclusion
Octopuses are carnivorous predators. They eat any animal that is smaller than them, but their main food sources are crustaceans, mollusks, and fish. Octopuses additionally eat baby turtles and small pelagic birds from time to time. Captive octopuses should be fed the same as wild ones, but they also eat frozen shrimp and animal-based food items.
Baby octopuses eat copepods, larvae, planktons, and each other in the larval stage. Juvenile octopuses begin their life stage with the same diet and progress toward their adult diet. They either hunt for slow-moving animals or ambush fast-swimming prey. Octopuses can eat up to four percent of their body weight.
FAQs
Do Octopuses Eat Humans?
No, octopuses do not eat humans. They are cautious around us and flee when they are disturbed. Octopuses prefer smaller animals to prey upon. If octopuses become offensive, they are generally weaker than us, and their venom (apart from the blue-ringed octopus) is too weak to harm us.
Do Octopuses Eat Themselves?
Yes, octopuses eat themselves and each other. Octopuses are known to be cannibalistic. As they are solitary animals, they only leave their dens when they want to hunt or mate. If an octopus encounters a smaller octopus when it doesn’t want to mate, it might see it as prey. Octopuses are susceptible to self-harm after mating and might gnaw off chunks of their arms.
Are Octopuses Prey or Predators?
Octopuses are both prey and predators. They prey upon smaller animals, so the risk while hunting is reduced, but they are hunted as well. Octopuses behave like prey when they are attacked, with their first instinct being to flee. Large carnivorous fish, orcas, whales, and some pelagic birds are all octopus predators.
