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...
