Chapter Ten: Biology of the Octopus: In which we Learn the Truth about the Gentle and Harmless Octopuses, Including the Correct Plural.

Hooray for Ellis – he gives us TWO chapters about octopuses! XD

This chapter was fascinating, for example: “Because they are soft-bodied with tissues that are made up mostly of uncompressible liquid, the deep-sea octopods are not affected by he tremendous pressure at these depths” (Ellis 284). Octopoda is the order that includes all octopuses. There are two suborders, Cirrata and Incirrata.

>The Cirrothauma (“thauma” means “wonderful” in Greek) is known as the “blind octopus.”

>The Opisthoteuthis is known as the “flapjack devilfish” (see a picture here).

>Octopus chierchiae is known as the “zebra octopus.”

>Hapalochlaena maculosa is known as the “blue-ringed octopus.” It has a poisonous bite that is strong enough to kill a man in five minutes. This tiny guy lives in the waters near Australia.

>Thaumoctopus mimicus is known as the “mimic octopus.” Watch a video of this amazing octopus here. This creature was officially named in 2005 and is about 2′ long. Little is known about this animal, but if you watch the video it is easy to see that it is quite intelligent.

The vampire squid has perhaps the coolest scientific name out of any animal: Vampyroteuthis infernalis; that translates as “vampire squid of the infernal depths.” But it is fact not a squid (or an octopus). It belongs to its own order: Vampyromorpha. This creature lives 3,000+ feet beneath the surface of the sea. It has proportionally the largest eyes of any creature in the world. A 6″ specimen will have 1″ eyes. It has photophores all over its body that it can turn on and off at will.

If the two following quotes don’t blow your mind, well, I give up.

“…an octopus embryo still in its egg case can change color to match its surroundings, that a blind octopus can do likewise, and perhaps most startling, that the skin continues to change color even after the animal has died” (Ellis 294.) A newborn common octopus is about the size of a flea but can still change color!!

“Sometimes it [an octopus] can secrete a fluid that liquefies the flesh of a victim even before it is ingested, meaning that digestion can take place outside the octopus” (Ellis 294).

Some interesting words from this chapter:

“Iridocyte” – iridocytes are tiny cells containing reflector platelets that impart an iridescent shimmer to the body.

“Ocelli” – a type of simple eye common to invertebrates, consisting ofretinal cells, pigments, and nerve fibers; or, an eye-like spot, such as on a peacock feather.

Fun Fact: scientists think that Octopus vulgaris is probably color blind.

Fun Fact: scientists believe that emotions are closely linked to the color change mechanism of octopuses.

Fun Fact: the third arm to the left [on an octopus] is hectocotylized (this means that it is a sexed arm).