<P> Giant squid and some other large squid species maintain neutral buoyancy in seawater through an ammonium chloride solution which is found throughout their bodies and is lighter than seawater . This differs from the method of flotation used by most fish, which involves a gas - filled swim bladder . The solution tastes somewhat like salmiakki and makes giant squid unattractive for general human consumption . </P> <P> Like all cephalopods, giant squid use organs called statocysts to sense their orientation and motion in water . The age of a giant squid can be determined by "growth rings" in the statocyst's statolith, similar to determining the age of a tree by counting its rings . Much of what is known about giant squid age is based on estimates of the growth rings and from undigested beaks found in the stomachs of sperm whales . </P> <P> The giant squid is the second - largest mollusc and one of the largest of all extant invertebrates . It is only exceeded by the colossal squid, Mesonychoteuthis hamiltoni, which may have a mantle nearly twice as long . Several extinct cephalopods, such as the Cretaceous vampyromorphid Tusoteuthis, the Cretaceous coleoid Yezoteuthis, and the Ordovician nautiloid Cameroceras may have grown even larger . </P> <P> Giant squid size, particularly total length, has often been exaggerated . Reports of specimens reaching and even exceeding 20 m (66 ft) are widespread, but no specimens approaching this size have been scientifically documented . According to giant squid expert Steve O'Shea, such lengths were likely achieved by greatly stretching the two tentacles like elastic bands . </P>

Where does the giant squid live in the ocean zone