Giant Squid
(Architeuthis dux)

The giant squid is one of my favorite invertebrates. I remember when the showed Peter Benchley's "The Beast" on TV, I watched it and pointed out all the mistakes. So...how big is "giant"? Well, on average about 60 feet. Like all squids, the giant squid had 10 tentacles. 8 are shorter and lines with suckers, and the other two are significantly longer, with paddle-like protrusions at the ends. The tentacles of Architeuthis can be locked together while the tips move free, so they can be used like tongs. The suckers are also lined with "teeth", which allow them to grip prey, and are the reason that sperm whales have circular scars on their skin. The mouth of the squid is a movable beak, with a rasping tooth-lined tongue called a radula inside. Squid are mollusks, like clams and snails. They move by jet propulsion, ejecting water at high pressure out of their siphon, a tube that allows for large quantities of water to pass the squid's gills. Needless to say, squid are very fast swimmers. They are also quite neurologically advanced, with a giant axon and eyes similar to ours...except their eyes are the size of hubcaps. They mate by having the male squid insert his modified fourth arm, the hectocotylus, into the female's mantle cavity (the main body of the squid is called the mantle), where he deposits a spermatophore. This is a packet of sperm. In order to stay neutrally buoyant, the giant squid has ammonium chloride in its tissues. Less dense than sodium chloride (salt water), it provides buoyancy to the squid. Not much is known about Architeuthis, because one has never been seen alive. The only specimens have been found dead, washed ashore or in sperm whales' stomachs. Thus, some information on giant squids is conjecture. They may turn out to be even more amazing than we think.