Mark Brockman, age 9, of E1 Paso, Texas, for his question:

HOW BIG IS A SQUID?

A squid is a mollusk. This is an animal with a soft, boneless body similar to the octopus nautilus and cuttlefish. Squids live throughout the world and range in size from less than a foot to nearly 40 feet in length, including the arms. A giant squid may measure 55 feet long.

The squid will never win a beauty contest. The dark gray body has red spots. The body has two fins at the tail end. The head is surrounded by 10 arms, two rows of which are longer than the others. Each arm has rows of round sucking discs which it uses to catch and hold its prey. .

The squid's head has two well developed eyes, a pair of powerful jaws and a rough tongue called a radula. A muscular tube, or funnel, lies beneath the head. The squid swims by filling the folds in its body walls with water and forcing it through the tube. This "jet" action makes the animal move.

An "ink sac" spurts .a dark fluid when a squid flees from an enemy. Squids can also change color to blend with the environment.