Amphioctopus marginatus

The coconut octopus lives in warm seas.

It likes sandy spots with many shells. This octopus is very smart. It finds shells to use as homes. It even uses trash like bottles to hide.

It can walk on just two arms. This looks like a rolling coconut. It eats small crabs and shrimp. The mother stays to guard her eggs. She will not eat until they hatch.

The coconut octopus lives in warm, tropical waters.

You can find them in the Indian Ocean and the Pacific Ocean. They like to live in shallow water near sand and mud. They often look for spots with many shells or bits of trash.

This octopus is very smart. It uses tools to stay safe. It finds coconut shells or clamshells on the sea floor. The octopus carries these items to make a hiding place. It can even use man-made trash like bottles for shelter. This is one of the first times we have seen such tool use in small sea creatures.

They have a very special way of moving. This is called bipedal locomotion, which means walking on two arms. They roll two arms to walk like stilts. They use their other six arms to hide their body. This might make them look like a rolling coconut.

Female octopuses lay large groups of eggs. They lay them in long, woven chains. The mother stays to guard the eggs in a shell. She does not eat while she waits for them to hatch. The eggs hatch in about 15 to 17 days.

The coconut octopus is a very clever sea creature. It lives in warm, tropical waters. You can find it in the Indian Ocean and the Pacific Ocean. It likes to stay in shallow areas with sand or mud. This octopus loves places with many shells or bits of litter.

These items help it find a safe place to hide. It is a medium-sized animal with dark, vein-like lines on its body. Its arms are usually dark, but its suckers are light in color.

This octopus has a very special way of moving. Scientists call this bipedal locomotion, which means walking on two legs.

The octopus rolls two arms to walk like stilts. It uses its other six arms to hide its body. It might do this to look like a rolling coconut. This helps it move while staying hidden from danger. It is one of only two octopus species known to do this.

One of the most amazing things is how it uses tools.

In 2009, researchers in Australia saw this in action. They saw the octopus collect coconut shells and clamshells. It carries these items to build a round hiding place. It can even use man-made trash like bottles for shelter. This is likely the first time we have seen such tool use in invertebrates. An invertebrate is an animal without a backbone.

We have learned a lot about this animal over many years.

A Japanese scientist named Iwao Taki first described it in 1964. He named it marginatus because of the pale border around its eyes. In 2005, researchers at UC Berkeley studied its walking. In 2017, scientists even mapped its entire mitochondrial genome. This is a special set of DNA that helps us see how it is related to other species.

Life for a coconut octopus can be quite busy.

Females lay huge groups of eggs in long, woven chains. Each clutch can have 100,000 eggs. The mother stays in a shell to guard them. She does not eat while she waits for them to hatch. The eggs hatch in about 15 to 17 days. After they hatch, the tiny young live in the open ocean. This way of life helps the species stay part of the sea.

The coconut octopus, scientifically known as *Amphioctopus marginatus*, is a medium-sized cephalopod. It lives in the warm, tropical waters of the Indian Ocean and the western Pacific Ocean. This species is also called the veined octopus because of its unique appearance. It is a member of the Octopodidae family. These animals are important to study because they show very complex behaviors. They live in shallow, subtidal waters along the continental shelf. They prefer sandy or muddy areas that contain many shells or debris.

One of the most remarkable things about this octopus is its ability to use tools. In 2009, researchers from the Melbourne Museum observed this behavior in Bali and North Sulawesi, Indonesia. They saw the octopus collect coconut half-shells from the sea floor. These shells were often discarded by humans. The octopus then carries these pieces to arrange them around its body. This creates a spherical hiding place that looks like a clamshell. This is considered the first evidence of true tool use in invertebrates, which are animals without backbones. The octopus uses these gathered items for both concealment and defense. It can even use man-made litter, such as bottles, to build a shelter.

This octopus also has a very unusual way of moving called bipedal locomotion. This is often described as "stilt-walking." In March 2005, researchers at the University of California, Berkeley, published findings on this in the journal *Science*. The octopus rolls two of its arms to walk like stilts. It uses its remaining six arms to disguise its body. Scientists believe this disguise might make the octopus look like a rolling coconut. This behavior was first seen off the coast of Sulawesi, Indonesia. *Amphioctopus marginatus* is one of only two octopus species known to walk this way. The other species is *Abdopus aculeatus*. Dr. Crissy Huffard noted that octopuses are the only animals without a rigid endo- or exoskeleton that can walk bipedally.

Physical characteristics help identify this specific species. The main body is medium-sized, but the total length can reach approximately 28 centimeters when including the arms. An adult can weigh up to 400 grams. Its skin displays a pattern of dark, branching lines that look like veins. The arms are usually dark, which makes the light-colored suckers stand out. During certain color displays, a light triangular area appears just below the eye. The specific name *marginatus* comes from the Latin word *marginum*. This refers to the pale border found around the eyes of the animal.

The history of our knowledge of this species involves several important scientists. A Japanese malacologist named Iwao Taki first described the species in 1964. He originally named it *Octopus marginatus*. Later, it was moved to the genus *Amphioctopus*. In 1976, a researcher named Dong Zhengzhi described the species as *Octopus striolatus*. However, that name is not considered taxonomically valid today. In 2017, scientists reached a new milestone by sequencing the complete mitochondrial genome. This is the DNA found in the mitochondria of cells. This sequencing showed that *A. marginatus* is closely related to *Amphioctopus aegina*.

The life cycle of the coconut octopus is intense and demanding. The species preys on crustaceans like Calappa crabs and various bivalves. Females lay massive clutches of eggs, sometimes containing 100,000 eggs at once. These eggs are laid in long, woven chains. The female finds a shelter, such as a coconut shell, to protect them. She stays to guard and tend to the eggs for 15 to 17 days. During this brooding period, the female does not eat. As a result, she will often starve to death while protecting her offspring. Once they hatch, the tiny paralarvae live as planktonic organisms in the open water.

Currently, the coconut octopus is listed as "Least Concern" on the IUCN Red List. This means it is not currently at high risk of extinction. However, fishing remains the primary threat to the species. They are found at depths up to 100 meters. They thrive in areas where there is enough litter to provide cover. Their ability to adapt to different materials makes them very successful in their habitats. By studying their movement and tool use, scientists learn more about how intelligence works in the ocean.