The above photo was taken at Camile's Reef, Key Largo, FL on
02/19/2006............ROD
Octopus vulgaris
New Video on Page 2
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.
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