Octopi, the Marine Einsteins Trivia Quiz

Answer: Hide in very small places

A fifty-pound octopus can fit through a hole that is only two inches (5cm.) across. If they can fit their rostrum through it, the rest of them can follow. Many divers have been the victim of a surprise attack by an octopus that they never saw coming. The lack of bones and no external shell make the octopus very flexible and maneuverable.

Answer: Jet propulsion

Most octopi move through the water by crawling and occasionally by jet propulsion, when faster speeds are needed. It requires a great deal of energy for the octopi to move in this manner, so the favored method of locomotion is slowly crawling. They contract their mantle and forcefully expel a jet of water which propels them forward, hopefully into safety.

They are one of the very few animals that are able to do this.

Answer: Look at its third arm on the right.

I know that this might sound a little strange, but you tell the sex of an octopus by looking at the tip of its third arm on the right. First, you find the eyes of the octopus, then, starting from a point between the eyes you count arms clockwise. On the third arm, a male will have a specialized tip that has no suckers on the last few inches.

This specialized tip can be seen even on a baby octopus. To mate, the male inserts this special arm into the female's body cavity. Captured male octopus can often be observed protecting this specialized arm.

Answer: They have three hearts.

An octopus has three hearts, two of which are used exclusively to pump blood to their gills. The third heart pumps their blue blood to the rest of the octopus' body. The octopus also has blue blood which contains hemocyanin, which is very effective at transporting oxygen in low temperatures and in low concentrations.

Answer: Suckers

Along the length of an octopus's arms are suckers which are used to hold things, help propel them through the water, and to taste food. The taste buds of an octopus are located on the suckers at the ends of their arms. Octopi have been known to be very picky eaters and have been observed passing up meals if they don't care for the taste.

Answer: Chromatophore

Octopi have special skin cells that are called chromatophores. These enable an octopus to blend into their background. They can help change both the color and the appearance of the epidermis. The camouflage provided by these specialized cells can turn an octopus from a prey species into a predator with a simple change of appearance.

Answer: False

Octopi have eight arms not eight tentacles. Arms and tentacles are not the same thing. This is a common mistake. Arms have suckers that run the length of the arm while tentacles usually only have suckers at their tips. In animals that have both, such as the octopus's cousin, the squid, the tentacles are always longer than the arms.

Answer: They die.

Death follows shortly after successful procreation for the octopus. When a female becomes fertile, multiple males insert their spermatophore into the tube that the female uses to breathe or they simply hand over their sperm. After this, the male leaves the female and goes off to die.

The female lays over 300,000 eggs which she obsessively guards until they are born. During this time, the female quits eating. Once the babies hatch, her body turns on itself and she starts suffering organ failure. The female usually dies before the male, but mating is a one time deal for the octopus.

Answer: False

Octopi are very old animals. Even though octopi do not have shells or bones, many octopus fossils have been found. Fossils as old as 296 million years old have been found. These fossils prove that octopi had already evolved long before dinosaurs and have changed very little over time.

Answer: Squirting ink

Octopi use a defensive ink spray. It hides the octopus as well as physically harming its enemies. The ink contains a substance known as tyrosinase which causes a blinding irritation in the eyes of its predator. It also upsets the predator's sense of taste and smell, causing them to become disoriented. Octopus ink is so potent that if they do not escape their own ink cloud, it has been known to cause their death.

The image shows arros negre, a popular Spanish seafood dish that makes use of squid and/or octopus ink.