Teuthida ordo_authority = A. Naef (Adolf Naef), 1916 subdivision_ranks = Suborders subdivision = ?Plesioteuthididae (incertae sedis) Myopsina Oegopsina

Squid are marine (marine (ocean)) cephalopods of the order (order (biology)) Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry (Symmetry (biology)#Bilateral_symmetry), a mantle (mantle (mollusc)), and arm (cephalopod arm)s. Squid, like cuttlefish, have eight arms (cephalopod arm) arranged in pairs and two longer tentacles. (The only known exception is the bigfin squid group, which have ten very long, thin arms of equal length.)