Do we have octopus and are they dangerous?
April 15, 2004
Yes, we have octopus and no, our species, Octopus
vulgaris, isn’t dangerous. Most octopus
are completely harmless, excluding the small, blue-ring
octopus of Australia that can inject a dangerous
and sometimes deadly neurotoxin.
Our octopus, Octopus vulgaris is found
worldwide in tropical and semitropical waters. It
can live in near shore waters, or as deep as 600
feet. Like most of the world’s 200 octopus
species, it is secretive and needs reef and rocky
bottoms for hiding. Although our sandy ocean bottom
doesn’t always fit the bill, hard bottom ledges
and shipwrecks just off our coast provide ample
Octopus can be hard to find because
superior skill at camouflage.
Octopus vulgaris has a short life span, only 12
to 18 months. The female lays eggs in long string-like clusters,
attaching them beneath a rock or other hard object. She
stops eating and guards the eggs until they hatch, after
which she dies. After hatching, hundreds of young octopus
spend between 45 to 60 days bobbing around in the ocean’s
plankton-rich waters before settling down to a bottom-dwelling
Octopus are credited with amazing intelligence, and their
well-developed central nervous system has been well documented.
Their vision is excellent, and they exhibit complex behaviors.
They are masters at coordinating their eight independently
working arms, or tentacles. Each arm is equipped with numerous
suckers that feel, grip and taste. This requires substantial
brain power. They quickly learn to navigate mazes, distinguish
colors and shapes, and even unscrew jar lids to get at food
inside. They diet consists mainly of crabs, shrimp, lobsters
and other crustaceans.
Octopus can change color in an instant, sometimes flashing
from light to dark to brown to white to red to purple. They
use this color-changing ability primarily for camouflage,
however, some studies suggest it indicates mood –
fear, mating, threats, territory, etc. Their rapid color-changing
ability is unsurpassed in the animal kingdom and demands
considerable neural coordination. They can also emit a cloud
of black ink, hoping to confuse their predator, and can
swim amazingly fast when threatened. The major predator
of our Atlantic species is moray eels.
Octopus vulgaris, may weigh up to 50 pounds and
attain a 10-foot arm span, although the average is more
like a few pounds and a 3-foot arm span. They are shy, quiet
and retiring, and their favorite food is crabs.