I have been observing squid underwater for many years and I find them to be one of the most fascinating creatures in the sea. In my opinion they are both the ultimate predator and prey. As an angler, your knowledge of squid and their behavior can help you land more and larger fish. Here are some intriguing facts about squid:

Squid are invertebrates in the phylum Molluska, a group that includes snails, clams and oysters. They belong to the Class Cephalopoda along with octopus, cuttlefish and nautilus. There are about 400 species of squid, all of which are marine and are found from the Arctic to Antarctic in all depths of water

The most abundant of the American squids are the northern squid (Ommastrephes illecebrosus), ranging from Southern New England to Newfoundland, and the southern squid (Loligo Pealii), ranging from Virginia to Massachusetts.

They are the second most plentiful animals -- after fish -- in the ocean.

They move by jet propulsion, allowing water into their mantle and forcing it out through their siphon. They use their siphon and fins to make quick changes in direction. Some can even fly through the air. They can move backwards or forwards with ease:

They have three hearts: one for their body systems and one located at the base of each gill so that they can pump oxygen to their muscles quickly, thus enabling them to swim fast.

Their nerve fibers are very large compared to human nerve fibers, enabling them to carry messages at 50 mph compared to 4.5 mph in humans. Scientist have been studying their neuron transportation system for many years.

Controlling color is another example of the finely-tuned nervous system of cephalopods. Squid can selectively control pigmented organs called chromatophores thus changing their skin color, pattern and even texture rapidly and on demand. These colors can range from a bright red, pink, and rust color to a greenish hue to almost translucent.

Here is a close up look at a pattern of color controlled by the chromatophores:

Squid normally feed at night. Here is an animation from video that shows a Loligo attacking a spearing or silverside. You will notice that the squid grabs its prey with its two tentacles, each equipped with suckers (only at the ends where they form pads) and then pulls the silverside into its eight waiting arms. Finally, the prey is held next to the beaklike jaws where pieces are bitten or torn off and then transported into the body cavity by a tongue-like radula.