Known as one of the most intelligent animals in the ocean, many factors make octopus so intriguing, including their camouflage skills, their multiple hearts, their locomotion technique, and their use of tools (in the case of the coconut octopus). We don’t like to pick favorites, but here are the five octopus species we’d most like to see on a dive.
The most poisonous
The blue-ringed octopus (which divides into four distinct species) is one of the most poisonous animals on the planet. Despite its small size (10 to 20 cm), its powerful venom causes muscle paralysis and can kill and adult person within a few minutes.
Luckily, however, they are docile and not aggressive toward humans, and they tend to hide and camouflage during the day. If they are provoked or feel threatened, the rings on their body will get brighter and display a flashing color pattern.
Like a lot of octopus, they prey on crabs and shrimp, as well as small fishes, piercing the other animal with their beak and using venom to paralyze it. You can find them on reefs and in tide pools in the Pacific and Indian Oceans, more specifically in Australia (Sydney/Melbourne), Indonesia (Bali, Lembeh, Raja Ampat, Komodo), Malaysia (Mabul), Philippines (Anilao, Puerto Galera), and Japan.
The con artist
The mimic octopus gets its name from its incredible imitation abilities. Like all octopus species, they can change color and shape, but they can also mimic other species by reproducing their behavior and shape in order to scare off predators. In an instant they can “turn” into a flounder, a lionfish, a sea snake — it’s the only animal that can imitate so many different others. It’s an amazing sight to see underwater.
Mimics are fairly small and grow to about 2 feet (60 cm) including arms. They have a fairly distinctive light brown/beige color, but the pattern tends to change to brown/white when they are defensive.
You’ll spot mimics most often in Indonesia, though they also inhabit the Red Sea, Gulf of Thailand and Great Barrier Reef. They tend to prefer estuaries and river mouths to reefs, so this is where you have the best chance to spot them.
At only .75 inch (2 cm) long and weighing less than a gram, the wolfi octopus (also known as the star-sucker pygmy octopus) is the smallest species known today. You’ll commonly find it in the Western Pacific’s shallow waters. In terms of coloration, it typically displays a light brown/pink color. Their size makes them hard to spot, and there is little data about this species, although it was identified in the early 1900s.
Though they’re all smart, the smartest octopus of all might be the coconut octopus. These animals have learned how to use a coconut, or sometimes another shell, as both a home and a defense mechanism. They display a rare aptitude called bipedal movement, meaning that they use two legs to walk on the sea floor while the others hold the shell as protection or camouflage.
Coconut octopus are quite small, reaching up to 10 inches (23 cm) including arms. They are usually brown with sometimes distinctive, glowing suckers, which is why they are also called “blue-glowing coconut octopus.” They inhabit tropical waters all over the Pacific, including Indonesia, Australia and South Africa.
The giant Pacific octopus is the biggest species scientists know today, with one specimen recorded at 156 pounds (71 kilos). Their arm span can reach between 13 to 20 feet (4 to 6 m) among the biggest individuals. They also have quite a long lifespan compared to other octopus species, from 3 to 5 years. They have one of the fastest growth rates, up to 0.9 percent per day from the moment they hatch until they become full-size adults.
You can find them on the North Pacific coast from Alaska to California, as well as in Russia and Japan. This species is quite popular in aquariums; they display very intelligent behavior and seem to recognize specific humans after a while. They can also solve puzzles and display problem-solving skills.