How fast do octopuses grow

Lizards can regrow their tails using special, undifferentiated cells, but the new tails might be stumpier than the original. JoAnna Wendel. They can regenerate lost limbs. They do this by reorganizing cells near the wound to create whatever body part they need. Octopuses have powerful jaws and venomous saliva, according to National Geographic. Octopuses weren't always squishy creatures. The ancestors of octopuses and squid sported hard shells. A study published online March 1, in the journal Proceedings of the Royal Society B: Biological Sciences revealed these marine animals lost their hard "mobile homes" in the Jurassic and Cretaceous periods.

This shell loss likely helped the ancient relatives of today's octopus, squid and cuttlefish become more agile to evade predators and nab prey, the researchers said.

An octopus has three hearts. One pumps blood through its organs; the two others pump blood through its gills, according to the World Animal Foundation. Octopus blood is blue because it has a copper-based protein called hemocyanin. When an octopus is swimming, the organ that delivers blood to the organs stops beating.

This exhausts the octopus, which is likely the reason they prefer to crawl than swim, according to the Smithsonian article. Octopuses come in many different sizes. The common octopus Octopus vulgaris is 12 to 36 inches The giant Pacific octopus Enteroctopus dofleini is the largest octopus.

They typically grow to 16 feet 5 meters long and weight around lbs. The smallest octopus is the Octopus wolfi. It is smaller than an inch 2. Octopuses live in oceans all over the world. Most are pelagic, meaning they live near the water's surface in shells, reefs and crevices. Some species live on the floor of the ocean, making their homes out of caves.

Octopuses tend to be solitary, though they do interact with other octopuses at times. Some species of octopuses hunt at night, while others only hunt at dusk and dawn. When scared, octopuses will shoot a dark liquid, sometimes called ink, at the thing that scared them. This will temporarily blind and confuse a potential attacker, giving the octopus time to swim away. Octopuses can also change color to hide and match their surroundings.

They can turn blue, gray, pink, brown or green. The mimic octopus can also flex its body to resemble more dangerous animals, such as eels and lionfish, according to the World Animal Foundation. If an octopus does get caught — no problem. They can lose arms and regrow them, according to National Geographic. Other research found that, when encountering a piece of food, a severed limb will snatch it up and try to move it in the direction of a phantom octopus mouth.

To do this, octopus use a protein called protein acetylcholinesterase, or AChE. Harmon describes what happens when an octopus loses its leg:. Around that time, a mass of stem cells and a hefty amount of blood vessels have arrived at the site.