page_title: Cephalopod size
section_title: Largest reported animals
hierarchical_section_title: Cephalopod size / Maximum size / Historical claims / Giant squid / Largest reported animals
caption_attribution_description: English: Figure 13: Linear regressions for Architeuthis dux. (A) Log10 Total Length (m) and Log10 Mass (kg). (B) Log10 Mantle Length (m) and Log10 Total Length (m). (C) Log10 Mantle Length (m) and Log10 Mass (kg). See Table 2 for regression equations.
context_page_description: Cephalopods vary enormously in size. The smallest are only about 1 centimetre long and weigh less than 1 gram at maturity, while the largest—the giant and colossal squids—can exceed 10 metres in length and weigh close to half a tonne, making them the largest living invertebrates. Living species range in mass more than three-billion-fold, or across nine orders of magnitude, from the lightest hatchlings to the heaviest adults. Certain cephalopod species are also noted for having individual body parts of exceptional size. The giant and colossal squids, for example, have the largest known eyes among living animals.
  Cephalopods were at one time the largest of all organisms on Earth, and numerous species of comparable size to the largest present day squids are known from the fossil record, including enormous examples of ammonoids, belemnoids, nautiloids, orthoceratoids, teuthids, and vampyromorphids. In terms of mass, the largest of all known cephalopods were likely the giant shelled ammonoids and endocerid nautiloids, though perhaps still second to the largest living cephalopods when considering tissue mass alone.
  Giant cephalopods have fascinated humankind since time immemorial.
context_section_description: Paxton (2016a) investigated the maximum size of Architeuthis by performing a statistical analysis using data from literature records of giant squid specimens. He selected what he regarded as the largest size records for each of mantle length (ML), standard length (SL), and total length (TL). Paxton's study has been criticised by giant squid experts, who have called into question the reliability of some of the selected literature records (Greshko, 2016).
  For mantle length, Paxton (2016a:83) considered the 11 ft (3.35 m) reported by Dell (1952:98) as the "longest measured", though "more reliably" the 9 ft 2 in (2.79 m) ML specimen from Lyall Bay, New Zealand, documented by Kirk (1880:312). Paxton added: "A 4.5 m [15 ft] specimen from Mauritius is often mistakenly cited but consultation of the primary paper (Staub, 1993) reveals an ill-defined length which is clearly not ML." The greatest measured ML of a giant squid recovered from a sperm whale is either the 2.4 m (7.9 ft) reported by Keil (1963:320) (though Paxton writes: "the account is confused and the 2.4 m figure probably refers to the head and ML combined") or the 6 ft 6 in (1.98 m) of a specimen that had been swallowed whole off the Azores, detailed by Clarke (1955:589) and Clarke (1956:257). The "longest visually estimated" ML, according to Paxton, is the c. 100 ft (30 m) of a specimen apparently observed in the North Atlantic off Portugal, attributed to a personal communication with T. Lipington. A more modest 4 m (13 ft) ML is also given, based on a sighting in the Indian Ocean sourced to the TV documentary of Lynch (2013).
  For standard length (excluding the tentacles), Paxton (2016a:83) cited the 31 ft (9.45 m) of the "Three Arms specimen" documented by Verrill (1880a:192) as the "longest measured". Among specimens recovered from sperm whales, the longest "definitely measured" SL is the 16 ft 3 in (4.95 m) reported by Clarke (1956:257) and the longest "visually estimated" SL is the c. 9 m (30 ft) attributed to a photograph of a sperm whale with giant squid remains in its jaws (see Hansford, 2009), though Paxton conceded that it is "[n]ot clear how much/what portion of body was eaten". For the "longest visually estimated", more extreme supposed SLs of c. 175 ft (53 m) and c. 100 ft (30 m) are cited to Starkey (1963) and Ellis (1998a:246), respectively (the latter an eyewitness account by Dennis Braun). Paxton treated these last two size estimates as SLs as opposed to TLs because "squid do not generally leave their tentacles exposed except when grabbing prey and this appears to be the case for Architeuthis".
  For total length, Paxton (2016a:83) considered three records as candidates for the "longest measured": the 19 m (62 ft) specimen of Berzin (1972:199), the 55 ft 2 in (16.81 m) specimen described by Kirk (1888) as Architeuthis longimanus—a strangely proportioned animal that has been much commented on—and the 55 ft (16.76 m) "Thimble Tickle specimen" reported by Verrill (1880a:191), which is often cited as the largest giant squid ever recorded. Of the last one, Paxton wrote: "Sometimes mistakenly cited as 17.37 m (57 ft) but the source is clear that it is 55 ft long." The first two records, particularly that of Berzin, are more questionable, as Paxton explained:
  The accuracy of the two longest measured TLs of 19 and 16.81 m from a specimen found in the gut of a sperm whale from the Indian Ocean and from the specimen from New Zealand in 1887, respectively, should also be questioned but again are certainly not impossible. The New Zealand specimen (named Architeuthis longimanus Kirk, 1888) clearly has the largest ratio of TL to ML ever known in Architeuthis [...] which led [O'Shea & Bolstad, 2008] to suggest that the length was paced out and/or there was extensive post-mortem stretching. However, a re-reading of the original paper suggests that the specimen, although initially paced out, was actually measured, nevertheless the TL is at the edge of the 99.9% prediction interval range [...] and so it was certainly an unusual specimen. Berzin's (1972) Indian Ocean cla
caption: Log–log linear regressions for Architeuthis dux, from McClain et al. (2015): (A) total length vs. mass; (B) mantle length vs. total length; and (C) mantle length vs. mass
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