Thursday, October 25, 2012

Suckers – The Common Octopus

Originally published on Audubon Guides on July 23rd, 2012

A friend called me the other day and asked me why we don’t have octopuses in Florida. “Why?” I questioned. Apparently someone she knew was going snorkeling on the reefs in Biscayne National Park off the coast of Miami. The woman was deathly afraid of octopuses and wanted to make sure the world beneath the waves was devoid of the well-suckered ones. I laughed. We have plenty but they’re nothing to worry about.

Octopuses are mollusks, more specifically cephalopods. They’re related to snails, slugs, clams, oysters and squid. Like any carnivore, they come well equipped to hunt. Like any prey species, they are well equipped to defend themselves. Their greatest weapon perhaps is their brain, a well-developed organ with the processing power that rivals some birds and fish. Not bad for an invertebrate species in the same phylum as the slugs.

All octopuses are venomous and can secrete a chemical from their salivary glands that incapacitates prey (The only octopus that secretes a deadly neurotoxin is native to the oceans around Australia). A powerful parrot-like beak allows them to puncture the shell of their prey which is mainly mollusks and crustaceans. Cephalopod means “head” and “foot”, a perfect characterization of a massive head seemingly mounted on four pairs of legs. Each leg is armed with rows of hundreds of suckers that prevent prey from escaping their powerful grip.

Most fascinating is the ability of the octopus to change colors dramatically within seconds. The malleable mollusk is capable of squeezing and relaxing muscles that control chromatophores, specialized cells that contain a variety of pigments. These cells can mimic the color, texture and brightness of the octopus’s surroundings, enabling them to blend into their surroundings in an instant and not only ambush prey, but hide from predators.

If you snorkel or dive in Florida you will be among octopuses. The Common Octopus (Octopus vulgaris) is the – ahem – most common. You may not see them but they will most likely see you. Fear not, their preference is to remain camouflaged and undiscovered.

During a recent trip to the Mote Marine Laboratory in Sarasota, FL my son and I watched an octopus in an aquarium scramble across the interior glass and duck into a corner – in plain sight. It turned from a bright red to a mottled brown color. A pair of visitors ambled up, looked into the tank, scanning past the octopus and complained, “There’s nothing in here”.

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