FREE ESSAY ON THE OCTOPUS, MAN...

THE OCTOPUS, MAN...

They change color, texture, and body shape... have three hearts... are jet powered... have
members in every ocean of the world... have inspired legends and stories since recorded
history... are the most intelligent of all invertibrates, yet are related to clams and
oysters... have eyes and senses that rival our own... and can make their own smoke screen
decoys out of ink. They are Cephalopods - octopi, cuttlefish, squids, etc. - and they are
far more fascinating than one might think.
Cephalopoda means, "head foot", and they certaintly are of an ancient group... they first
appeared several million years before the first primitive fish began to swim the oceans,
in the late Cambrian era. They were once one of the dominant life forms in the sea, yet
today there are only 650 or so living species left. (This may seem like quite a bit, but
compare it to the 30,000 living species of bony fish on this planet 
and it loses its' prominence.) Yet in terms of productivity, some scientists feel that
cephalopods are still giving fish a run for their money.With so much information on
cephalopods available, it becomes neccesarry to narrow down the catagories. Thus, I 
have determined to zoom in on the order Octopoda as the main focus of this paper, a group
on animals which contains, in my opinion, some of the more interesting and intelligent
creatues on this planet.
Members of the order octopoda have eight arms. Over the corse of evolution, the trend has
been a reduction of shell size. Octopi, having no shells at all, have 
carried this trend the furthest. The suborder ncerrata contains the familiar, unfinned
octopuses that humans know the most about. Octopi have evolved 
mechanisms to protect themselves from predators. Some of the amazing abilities of octopi
include their ability to change theircolor, texture, and apparent size; to expel ink; and
to modify their environment to suit themselves. Octopi are able to jet water through
their siphon by contracting their mantel to provide quick, explosive thrust. They have
the intelligence and ability to get into and out of fishermen's crab 
and fish traps and to get under an undergravel filter plate in an aquarium. They can
adapt to new situations and appear to be curious about their surroundings. Octopi can use
their bodies as a nets to trap fish. Having very little hard material in their bodies,
usually only a beak and a radula, they can squeeze into amazingly small spaces. 
You would think that the lack of a hard defensive shell would make the octopus an easy
meal. However, the above adaptations that I've mentioned are often used together to
effectively evade their predators. An octopus could darken in color, expel a cloud of
dark ink, immediately jet away while turning white, and then disappear under a rock,
leaving the predator confused and somewhat perturbed at the situation. 
Although octopi possess beaks and cephalotoxins, and, if they wanted to or felt the need
to, could easily hurt or kill any human who dared to enter their 
territory, they generally do not affect man... but the exception is a beautiful
blue-ringed octopus from Australia. Though it is shy and definitely won't viciously
attack", it can, if it feels threatened, defend itself by delivering a venom that can
kill 
in minutes... so if you ever happen to find yourself splashing and swimming around the
Great Barrier Reef, just make sure to stay on your toes. 
The life span of octopi is short, varying from six months in the small species to three
years in the larger ones. It is believed that the hormone that regulates sexual
maturation is also associated with natural death. Another interesting aspect of octopi is
their reproduction. It is generally thought that cephalopods are fast growing animals
that reproduce once and then die. In Octopus briareus, an impregnated 
female can store viable spermatophore for as long as one hundred days after
fertilization!!! The eggs are generally laid in a protected lair and fanatically guarded
by the female. She usually eats very little or not at all during this period and dies
shortly 
after the eggs hatch. It has been observed that even unfertilized females lay eggs,
brood, and then die... ever-hopeful, it seems.Thus we learn about our underwater buddies,
the octopuses. Beautiful, intelligent, and far more advanced on the evolutionary chain
than many other creatures, the octupus remains another wonderful aspect of life on planet
Earth.