Posted by: Doc Bruce | March 13, 2008

A Noble Life in a Beer Bottle

A couple of weeks ago, I found a barnacle-encrusted beer bottle in the shallows of San Carlos Bay. As I talked about the merits of picking up litter versus the impact on the creatures living on the bottle, I absent-mindedly tried to empty the bottle of sand that had collected inside. Unable to shake the sand out, I poked my finger into the neck of the bottle to loosen some of the sand – still nothing. So I peered down the neck of the bottle and was joyously surprised to see a tiny suction-cup clad tentacle of a small octopus also claiming this bottle as home.

At first blush one might think this to be a ‘baby’ octopus, but on the contrary it was a grande dame dwarf octopus (Octopus joubini). Yes, some of our octopi can easily fit in a beer bottle as old, fully grown adults. We have two species of octopus on Sanibel, the common octopus (Octopus vulgaris) a large variety, and the dwarf octopus (Octopus joubini). Octopi are wonderful mollusks and have unbelievable capabilities to change not only the color of their skin, but also the texture of their skin – almost instantaneously. They are among the most intelligent of invertebrate animals; many scientists believe their intellectual capabilities very similar to those of the house cat. Next time your cat out-manipulates you, think octopus-brain.

Octopi are equipped with a beak (in their mouth) which is located at the confluence of their eight arms. They are extremely fluid and can fit through almost any opening large enough to accept the diameter of their beak. They are also armed with poison that they use to subdue their prey – mostly small crabs, but also an occasional bivalve mollusk. And beware, they are not in any way opposed to bite and sting humans who foolishly choose to pick them up and handle them – which of course I have been known to do from time to time. Take it from me, don’t handle them unless you are prepared for a bee-like sting and bite – just remember cat brain, beak and poison; a bad combination.

One of the most fascinating tidbits of the biology of dwarf octopi is that they only live for about one year. They hatch from eggs and within five months are fully grown and sexually mature. After a female mates, she lays her eggs on a firm substrate and stops eating. She remains with her eggs diligently guarding them until they hatch, shortly afterward she dies advancing age and starvation.

The ocean holds so many majestic mysteries – an octopus living out her lifespan out in a year’s time, forgoing food to guard her eggs then slipping beyond her existence; all in a beer bottle in the shadow of the C span bridge. And she is about as intelligent as the cats we know and love (or not) so dearly.

Pretty cool world we are surrounded by on our island home. Go check it out.


  1. Greetings, Bruce! My cat out-manipulates me almost daily! Guess all that animal behavior you taught me didn’t stick as much as it should have! I do still think about the vervet monkeys and selective learning, was it? And I have yet to dive as fine a place as South Water Caye! It looks like you and Evelyn are doing good things! That is great to see! I just wanted to say hello to an old friend- Hello, friend!Deana Schneider, L and C grad, 1997

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