Squids & Octopus

Squids and octopuses are cephalopods ( Latin: "head-foots". ) They are extremely evolved mollusks. The shell is internalized as a support structure in squids, or completely absent, as in octopi. There are probably more squids than fish in the sea, both by numbers and by mass.


Longfin Squid

Loligo pealei

Size: to 17"

Habitat: Generally deep waters, but moves inshore in the summer. I have seen small ones at depths of 50-70 ft and babies in the rivers.

Notes:

Longfin Squid

The squid is a mollusk, related to snails and clams. These animals travel in schools, swimming backwards by jet propulsion. Small specimens are nearly transparent except for the eyes. Tropical squids can show considerable intelligence and curiosity, but northern versions are, well, just stupid. I have seen huge schools of small transparent squids offshore, just their eyes visible, like black marbles. In the rivers, I have seen small schools of purple squids, and tiny colorless babies drifting in the current. All are predatory.


Common Atlantic Octopus

Octopus vulgaris

Size: see below

Habitat: rocks and coral reefs, all depths

Notes:

The Common Octopus is the most studied of all octopus species. Its natural range extends from the Mediterranean Sea and the southern coast of England to at least Senegal in Africa, as well as the Azores, Canary Islands, and Cape Verde Islands. In the western Atlantic, it ranges from Texas and Florida to New England, although uncommon in colder northern waters. Typical habitat is rocks and coral reefs. Young are planktonic, and total lifespan is only 12-18 months.

O. vulgaris grows to 25 cm in mantle length with arms up to 1 m long. They can weigh up to 20 pounds, although they are usually much smaller. O. vulgaris is caught by bottom trawls on a huge scale off the northwestern coast of Africa. More than 20,000 tons are harvested annually.


There are on the market today portable underwater direction-finding units that home in on each other by sound. These provide similar functionality to a strobe light, but with ( theoretically ) longer range, and are ( theoretically ) unaffected by water conditions and visibility. They are also very expensive, and prone to failure when a large object or wall gets between the two units. A number of times I have seen people get lost because they counted on one of these gadgets, and it didn't work.

Perhaps the most disturbing thing about these devices is that their users seem to be mostly beginners who place unfounded faith in them, probably because they paid so much for it at the dive shop. They seem to hit the water in "brain-off" mode, counting on their expensive gadgets to get them home, and making little or no effort at other forms of navigation. Unfortunately, these people are probably the least able to cope with the emergency situation that arises when they find out just how reliable their little sonar toy isn't. Learn to use a wreck reel instead.

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