Squid are cephalopods of the two orders Myopsida and Oegopsida, which were formerly regarded as two suborders of the order Teuthida, however recent research shows Teuthida to be paraphyletic. The two current orders comprise around 304 species.[2] Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles.