Colossal squid
The largest recorded specimen was captured in 2007 by a New Zealand fishing boat off Antarctica. It was initially estimated to measure in length and weigh . The squid was taken back to New Zealand for scientific study. A study on the specimen later showed its actual weight was , but it only measured in total length as a result of the tentacles' shrinking "post mortem".
Cephalopod size
Squids are the largest living cephalopods in terms of each of mantle length, total length, and mass, with the largest species by at least two of these measures being the colossal squid, "Mesonychoteuthis hamiltoni". Reaching an estimated in mantle length and in total length, and weighing as much as , this species is also the largest of all extant invertebrates (Rosa & Seibel, 2010; McClain "et al.", 2015; Rosa "et al.", 2017). The only other squid that approaches these dimensions is the giant squid of the genus "Architeuthis", with females up to , in mantle length, and possibly as much as in total length, making it likely the longest of all cephalopods (McClain "et al.", 2015). The two largest octopus species—"Enteroctopus dofleini" and "Haliphron atlanticus"—can both exceed , and the former has a maximum total length of more than . Cirrate (finned) octopods can also reach a large size, with the largest captured specimen likely being a "Cirrothauma magna" of total length and mantle length (Collins "et al.", 2001; Collins & Villanueva, 2006:294), though observations from submersibles suggest that members of this group can exceed in total length (Voss, 1988; Vecchione "et al.", 2008). Members of the other cephalopod groups are substantially smaller, although the largest cuttlefish can exceed in weight and in mantle length. Cephalopods of comparable size to the largest present day squid are known from fossil remains, including enormous examples of ammonoids, belemnoids, nautiloids, orthoceratoids, teuthids, and vampyromorphids (see Teichert & Kummel, 1960; Stevens, 1988; Eyden, 2003b; Larson, 2010; Iba "et al.", 2015).