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What does an octopus eat? – Lily, age 4, Maryland
The octopus is one of the coldest animals in the ocean.
For starters, they are invertebrates. This means that they do not have a backbone like humans, lions, tortoises and birds.
This may sound unusual, but in fact, almost all animals on Earth are invertebrates – about 97%.
Octopuses are a specific type of invertebrates called cephalopods. The name means “head-foot” because the arms of cephalopods surround their heads. Other types of cephalopods include squid, nautiloids, and cuttlefish.
What do they eat?
As marine ecologists, we research how ocean animals interact with each other and their environments. We’ve studied most of the fish, from lionfish to sharks, but we have to admit that we are infatuated with octopuses.
What octopuses eat depends on what species they belong to and where they live. Their prey includes gastropods, such as snails and sea slugs; bivalves like clams and mussels; crustaceans like lobsters and crabs; and fish.
In order to catch their food, octopuses use a lot of strategies and tricks. Some octopuses wrap their arms — not tentacles — around the prey to draw them to them. Some use their hard beaks to drill into clam shells. All octopuses are poisonous; They inject toxins to overwhelm their prey and kill them.
where do they live?
There are about 300 species of octopus, and they are found in every ocean of the world, even in the cold waters around Antarctica. A special substance in their blood helps those cold-water species obtain oxygen. Due to this their blood also turns blue.
You can also find octopuses at different depths. Some are found on warm tropical reefs a few feet below the water surface. Others live in the deep sea, practically in the dark. The deepest known species is the dumbo octopus, which is seen down to 22,800 feet—that’s more than 4 miles (about 7 kilometers).
How smart are they?
Octopuses are the head of the class. They are among the smartest invertebrates on Earth. They have nine brains – a small brain in each hand and the other in the center of their body. Each hand can taste, touch and perform basic movements independently, but all arms can work together when prompted by the central brain.
The octopus put his brain to good use. They can solve mazes and puzzles, especially when food is the reward. Sometimes they even outnumber people: At the New Zealand National Aquarium, Inky figured out how to get out of his tank and run through a drainpipe into the ocean.
How do they change colour?
Octopuses are experts at disguising themselves so that they can blend in with their surroundings. One way to do this is to change the color. Special cells, called chromatophores, receive a signal from the brain to tighten muscles to show more color, or loosen them to show less. Blue, green, pink, gray – they change those colors and more to hide from predators, attract mates, draw in prey and warn enemies to stay away.
Some species also change the texture of their skin, making it smooth or bumpy, so they can camouflage themselves in rocks and foliage. Some spray ink when encountered by predators such as sharks; This gives the octopus enough time to swim safely.
The mimic octopus is particularly clever. It moves its arms exclusively to imitate other marine animals. For example, if he wants to appear fierce, he spreads two black and white striped arms wide to look like a venomous sea snake. Or it flattens itself along the ocean floor, with arms next to its body, to look like a venomous flattened fish.
octopus in danger
When encountering humans, an octopus tends to be non-aggressive – as long as you give them space, like you would any sea animal.
Although octopuses have ways of evading predators, they remain at risk from other threats: chemical pollutants, marine debris, habitat loss, overfishing, and climate change.
But we humans can all help by making ocean-smart choices. This includes learning to cut carbon emissions and use less plastic. Doing these things will help octopuses and other sea creatures not only survive, but also thrive.
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