|
You
have probably noticed ‘cuttlebone’ pushed between the bars of a budgerigar’s
cage, or washed up on the beach. This ‘bone’ is not really bone at all but the
shell of a cuttlefish, which is not a fish but a mollusk. The cuttlefishes,
squids and octopuses belong to a group of of mollusk called cephalopods and most
are characterized by a very reduced shell or by not having one tall. The shell
in the cuttlefish is completely enclosed by the mantle and, being very light, it
helps to keep the animals buoyant. The foot of all the cephalopods is modified
to form either eight or ten tentacles which surround the head (cephalopod means
head-footed). These bear suckers along their length and its is with them that
the animals catch their pray. The edge of the mantle of the cuttlefish forms two
flaps at the sides and by undulating these the animal swims about quite
leisurely. In an emergency, greater speed is obtained by forcing out a jet of
water from the mantle cavity through a funnel. The funnel can be directed in any
direction and if suddenly attacked, the cuttlefish can shoot off out of danger.
Website of Facts
|
