Physical description and related species Squid are a diverse
group of invertebrates (animals without backbones), and range in
size from barely two and a half centimetres (Idiosepius sp.) to
a total length approaching 18 metres (giant squid Architeuthis
sp.). The largest invertebrate in the world is the giant squid,
which can grow to 15 m. The giant squid has the largest eye in
the animal kingdom. It is much bigger than the eye of a blue
whale! That is about the size of a volleyball. Squid belong to a
group of molluscs called cephalopods, which also includes
octopuses, cuttlefish and their allies. There are approximately
70 species of cephalopods found in the Southern Ocean. The warty
squid reproduces by the female producing a huge ovary the size
of a football while breaking down all muscle from her body wall.
After spawning they die, with spent individuals floating to the
surface where they become important dietary items for sea birds
such as albatrosses. Most squid complete their life cycle—from
tiny plankto