After coming across Cephalopod Day’s mention on my holidays calendar, I just had to get out my CD copy of “Abbey Road” by The Beatles, in order to hear “Octopus’s Garden”. Just hearing Ringo Starr’s voice describe the undersea fantasy makes me grin.
I soon found out that there are more Cephalopod Days this month, a whole string of them. The next one is Oct. 8. The visual pun is apparent when you see it written out. The next Cephalopod Days arrive, in succession, through Oct. 12th.
You may recall from your high school biology lessons that Cephalopoda is a Class within the Phylum, Mollusca. I memorized this fact by noting that the chambered nautilus resembles a snail; since snails are mollusks. Of course, cephalopods include more than octopuses and nautiluses. They also include cuttlefish and squids. There are about 800 species of cephalopod creatures throughout the seas. It’s noteworthy that cephalopods do not tolerate fresh waters, they must have salty or brackish waters.
Aside from their appearance, cephalopods are interesting because of their high intelligence. Researchers believe they are the most intelligent invertebrates. The creatures have evolved large brains and highly developed senses. The ethologist Frans de Waal wrote, “Octopuses have hundreds of suckers, each one equipped with its own ganglion with thousands of neurons. These ‘mini-brains’ are interconnected, making for a widely distributed nervous system. That is why a severed octopus arm may crawl on its own and even pick up food.”
Most of them are highly vision dependent animals. Even so, all octopuses, cuttlefish and squids are color blind. Nautiluses have only evolved a rudimentary eye that works like a simple pinhole camera.
When I see photos or videos of cephalopods, I’m not only fascinated by the creatures’ tentacles, but also, their ability to change color and camouflage themselves. Their colors and skin patterns can change in a split second. In addition to purposes of camouflage, some species use the ability to change color to signal their peers or to warn potential predators.
Another way that most cephalopod species confuse predators is the use of their dark ink. In addition to clouding the water, the ink can be used in conjunction with mucus to form a decoy or pseudomorph of the creature. This causes the predator to attack the decoy, instead of the departing cephalopod. The only exceptions to the ability to eject ink are the nautiluses and one species of octopus.
Regarding “Octopus’s Garden”: Ringo Starr was told by a boat captain that many types of octopuses skim across the sea bed and pick up shiny objects and small rocks with which, they construct “gardens”.