Squid Squid Squid are cephalopods in the order Teuthida with elongated bodies, large eyes, eight arms and two tentacles. Like all other cephalopods, squid have a distinct head, bilateral symmetry, and a mantle. They are mainly soft-bodied, like octopuses, but have a small internal skeleton in the form of a rod-like gladius or pen, made of chitin. Squid can change colour for camouflage and signalling. Some species are bioluminescent, using their light for counter-illumination camouflage. Squid are members of the class Cephalopoda, subclass Coleoidea. The squid orders Myopsida and Oegopsida are in the superorder Decapodiformes (from the Greek for "ten-legged"). Two
Colossal squid whales and sleeper sharks), while the other predators only eat juveniles or young adults. The species was first discovered in the form of two tentacles found in the stomach of a sperm whale in 1925. In 1981, a Russian trawler in the Ross Sea, off the coast of Antarctica, caught a large squid with a total length of over , which was later identified as an immature female of "M. hamiltoni". In 2003 a complete specimen of a subadult female was found near the surface with a total length of and a mantle length of . This specimen shows that