The giant squid, Architeuthis dux, was described by Steenstrup in Harting in 1860. It is the only species in the genus Architeuthidae.Giant squid are the largest known cephalopod. Colossal squid (Mesonychoteuthis hamiltoni Robson, 1935) may reach greater lengths or mass but no complete, fully grown specimens have ever been recorded.In the past, giant squid were often misreported as reaching lengths of up to 20 metres. Scientists now believe that adult females may only reach a total length of 15m, with adult males reaching up to 10m in length.Most of the giant squid material in museum collections comes from specimens that have been found washed up on beaches or come from the stomach contents of sperm whales which feed on giant squid.