The above photo was taken at Camile's Reef, Key Largo, FL on 02/19/2006............ROD
Octopus vulgaris
Description: Body plus longest arm 120" (3 m) long. Globe-shaped,
with 4 pairs of arms. Usually reddish-brown; color highly variable. Thick
arms 4 times length of mantle; with 2 alternating rows of suckers; tubular
siphon under neck; head almost as broad as body, eyes high on sides of head.
Skin mostly smooth, but can temporarily raise variously shaped bumps.
Habitat: Among rocks and coral reefs near shore; near low-tide line and below
in shallow water.
Range: Connecticut to Florida and Texas; Mexico; West Indies.
Notes: This octopus is secretive, hiding during the day in crevices and caves
and under rocks. Small specimens may be found above the low-tide line. The
Briar Octopus (0. briareus) ranges from southern Florida throughout the West
Indies, among coral rocks and reefs, and in turtle grass beds. Its length
is 18" (46 cm), its arms are thick at the base and over 5 times the mantle
length. It is usually pinkish-brown, but changeable, and its skin is smooth
or finely granular.
Source:
Audubon Society Field Guide to N. Amer. Seashore Creatures;
pg 579;
plate 480;
Size: 15-28 inches;
Depth: usually shallow water;
Only the
Common Octopus seen in the open during the day;
The
Caribbean Octopus seen in the open only at night.
Octopus vulgaris, the Common Octopus, is found world
wide in tropical and semitropical waters from near shore shallows to as
deep as 200 m. In actuality, most scientiststs believe that O. vulgaris
actually contains a number of related sister species. However, taxonomists
have not yet decided how to split the species. Another common identity
problem with the common octopus, is that in many commercial industries,
such as the food and aquarium trade, list all species of octopuses as O.
vulgaris.
Despite these identify issues, the O. vulgaris is commercially important
and accounts for a large percentage of octopus fisheries. From 20,000 to
100,000 metric tons are landed yearly. They are commonly collected in octopus
pots. These were traditionally made of clay but in modern times they are
typically made of plastic or PVC. Octopuses pots are not baited like crab
and lobster traps, rather, they provide a seeming safe home. In addition
to being commercially important, this species is also one of the most commonly
studied cephalopods.
Octopus vulgaris lives for 12 to 18 months. After they
hatch from on of 100,000 to 500,000 carefully guarded rice grain sized eggs,
they spend 45 to 60 days in the plankton. During this time, most of them
become food for something else. Those that survive settel out and begin a
benthic (bottom dweling) life. Dr. Roger Villanueva as well as several Japenese
workers are amoung the few people who have ever reared these small eggs octopuses
to settlement.
O. vulgaris is occasionally active during the day.
Dr. Mather reports that they are out hunting during the day 12% of the time
in Bermuda. In Cephalopod Behaviour, Hanlon and Messenger (1996) theorize
that cephalopods that live in complex environments are especially good at
camouflage and have a large reportuar of patterns. O. vulgaris certainly
fits this description as they can be incredibly good at matching their surroundings.
Finding them can be difficult.
Some species of octopuses, like Octopus vulgaris, leave
piles of shell and crab carapaces outside their lairs. These discards are
called midden and are useful to divers and scientists for several reasons.
O. vulgaris are masters of camouflage and it is often easier to search for
them by searching for midden piles than looking for the animals themselves.
While swimming above a reef numerous clean shells can catch your attention
from a distance of 5 meters or more, you are unlikely to see a camouflaged
octopus at half of that range unless it moves. Once you find a midden pile
the next step is to dice down and look for a lair. O. vulgaris lairs are
typically holes in rocks or excavated under or between rocks. If the octopus
is home, you are in luck. If not, a carefull look in the surrounding area
may find him as he is likely out hunting. If you still have no luck, your
chances are good if you take another look a few hours to a day later.
Scientists are interested in midden piles for two reasons.
One is that the discarded shells give us a very good idea of what the octopus
eats. Another is that the middens give us a different view of what animals
are in the area. For example, in Bonaire O. vulgaris was finding and eating
a number of mollusks that we never could find ourselves. One of these was
a rather large surf clam that the octopuses can obviously find. If it were
not for octopuses conveniently leaving middens for us, we would not have
been able to add surf clams and others species to our Mollusks of Bonaire
list.
< rodbigelow@netzero.net > 
