Octopods

I have heard much debate over the plural of “octopus.”  From octopuses, to octopi, to octopolodies and finally octopods!  For this post I will use octopus to refer to both a singular animal (an octopus) and the species as a whole (many octopus).  Problem solved!  Octopus are cephalopods, meaning “head-foot.”  Their feet, or arms are connected directly to their head.  The mantle is the large sac-like structure protruding from their head, and houses all the organs necessary for digestion and life of the animal.

Octopus are fascinating creatures.  I’m sure you have heard how smart they are, how they can figure out even the most complicated puzzles in pursuit of food, and how even giant octopus can squeeze themselves through the smallest of openings.  Here are some things that perhaps you didn’t know.

Giant Pacific Octopus are the largest of all the octopus species.  The largest animal every recorded had an arm span of 32 ft and weighted about 600 lbs!  All octopus lack any sort of skeletal system, and every part of their body is completely flexible, save the beak.  An octopus beak looks much like a bird beak, is composed of chitin, and is used for crushing prey.

Octopus have a toothed tongue called a radula.  They use this tongue to bore through shells so that they can eat the animal inside.  Have you ever been walking along the beach and found a shell with a very small, perfectly circular hole in it?  This was most likely made by an octopus.  Somehow, the octopus knows exactly where to bore a hole that hits the adductor muscle in the clam, thus weakening the clam.  The octopus is then able to open up the clam without a problem and dinner is served.

Octopus can change color using specialized cells called chromatophores.  These cells can change color from white, the relaxed state, to red, the excited state, in a matter of seconds.  The cells themselves do not change color; instead they contract or relax dictating how much pigment is visible.  When an octopus needs to hide quickly from a predator, it will turn completely red.  This may seem odd, as red is a rather noticeable color.  However red is one of the first colors to disappear as you drop to the ocean floor, making it the choice camouflage color for octopus.  Another camouflage tactic employed by the octopus is mimicry of its surroundings.  They will often stand tall and wave back and forth in the water to imitate kelp, or stealthily texture their bodies to blend in to a rocky cove to avoid being eaten.

Octopus arms serve many purposes, other than locomotion.  To capture food, octopus will pounce on their prey, expanding the webbing between their arms to create a tent that can be completely sealed.  They will then reach inside with an arm or two to secure their prey before ingestion.  During mating, a male octopus will reach a specialized arm inside the female to deliver the spermatophore.  This specialized arm is void of suckers near the tip, and instead has a small channel that assists in delivering the spermatophore.  Once a male has reached sexual maturity (at about 3 to 5 years) he will attempt to mate with as many females as possible during that season.  Octopus are semelparous, meaning once reproduction is over, they will die.  Female octopus can store the sperm before fertilization for up to 6 months.  Once the female has decided to fertilize her eggs, she will find a secluded den to lay up to 100,000 eggs in.  She will glue the eggs to the rock, and spend the rest of her life caring for the eggs.  To keep them aerated she will blow water over them using her siphon, and do her best to protect them from predators.  Once all the eggs have hatched, she too will die.

Lulu and her remaining eggs

Only one octopus has ever been successfully hatched and reared in captivity.  This is because once hatched, the paralarve are extremely delicate, require very specific nutrition, and are planktonic.  The SeaLife Center has 30,000 chances and is hoping for success with one!  Much still remains unknown about these creatures, but as we continue to learn we hope to uncover some of the mysteries of the Giant Pacific Octopus.