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Lives of the Other Mollusks 47
crippled individuals and used them for bait. A number of these giants have
been brought into museums, and others, stranded on beaches after storms,
have been measured and recorded by reliable observers. Architeuthis of the
North Atlantic waters is know^n to reach a total length of 55 feet. The
longest arms of this specimen are 3 5 feet, while the length of the body from
tip of tail to the base of the arms is 20 feet. The greatest circumference
of the body is 1 2 feet. Sperm whales which feed upon smaller squid have
often been locked in battle with these giants. The skin of these whales is
sometimes heavily marked with circular scars caused by the suckers of the
squid.
The octopus does not reach a very large size. The largest known species
occurs on the west coast of North America where, in Alaska, Octopus
punctatus attains a length of 16 feet or a radial spread of nearly 28 feet.
However, the arms are very small in diameter, and a specimen of such long
proportions has a body length of not more than a foot. The octopus oc-
casionally found in the Lower Florida Keys is usually less than three feet
in radial spread. A dead specimen cast on a beach near Nassau, Bahama
Islands, was reported to have an arm length of five feet, and it was estimated
that the entire creature weighed about 200 pounds. This, however, is with-
out verification. Recent reports of octopus holes 100 feet across seen in
the Bahamas from the air were made by untrained observers. There is no
satisfactory evidence that any of these species of Octopus has ever inten-
tionally attacked man, or that any person has ever been seriously injured
by one. The octopus is a rather sluggish and timid creature, seeking shelter in
holes and crevices among the rocks, and is usually small. It feeds mainly on bi-
valve mollusks but will also eat snails, fish and Crustacea. Its hideouts along the
shore can usually be detected by the presence of empty shells.
Locomotion among the cephalopods varies from a slow, "tentacle-walking"
pace, both in and out of water, to the rapid, jet-propulsion darts which
are so characteristic of the squid. The so-called aerial "flight" of squid, like
that of the flyingfish, is actually a gliding operation and largely depends
upon the initial speed attained under water. Squid have frequently landed
on the decks of ships a dozen or more feet above the surface of the ocean.
When a school of squid is alarmed by an approaching ship or by marauding
fish, the fleeing squid dart from the water simultaneously and all in one
direction rather than individually fanning out in several directions in the
manner of flying fish.
The squid darts backward, forward, or in any other direction by means
of the reaction of the jet of water which is ejected with great force from
the siphon, and direction of movement is controlled by the bending of the
siphon. Even when it is confined to a limited space, as in a fishpound, it is
not an easv matter to capture it with a dip-net, so rapid is its movement.