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
Based on a 40-year data set of more than 50 giant squid specimens, Roper & Shea (2013:114) suggest an average total length at maturity of and a "rarely encountered maximum length" of . Of the nearly 100 specimens examined by Clyde Roper, the largest was "46 feet (14 m) long" (Cerullo & Roper, 2012:22). O'Shea & Bolstad (2008) give a maximum total length of for females based on the examination of more than 130 specimens, measured "post mortem" and relaxed, as well as beaks recovered from sperm whales (which do not exceed the size of those found in the largest complete specimens). Steve O'Shea estimated the maximum total length for males at (O'Shea, 2003a). Older records of or more were likely exaggerated by stretching of the long feeding tentacles or resulted from inadequate measurement methods such as pacing (O'Shea & Bolstad, 2008; Roper & Shea, 2013:113). Charles G. M. Paxton performed a statistical analysis using literature records of giant squid specimens and concluded that "squid with a conservative TL of would seem likely based on current data" (Paxton, 2016a, b), but the study has been heavily criticised by experts in the field (Greshko, 2016). O'Shea has stated that, given the available evidence, the highest upper bound he would consider plausible for the giant squid's total length would be , and that the likelihood that there exist 20-metre giant squid is "so exceedingly remote that you couldn't justify the effort in writing about it" (Bittel, 2016). O'Shea contends that Paxton's estimates are skewed because his data set included unreliable (and exaggerated) records from the nineteenth century. Paxton has responded that even when these questionable records are excluded the analysis gives "a maximum length of just over 20 metres with a 99.9% prediction interval" (Bittel, 2016).