Unleashing the Kraken: on the maximum length in giant squid ( Architeuthis sp.)

Abstract Giant squid are among the largest invertebrates known, but a consensus on their maximum size is lacking. Statistical investigation of various measures of body length and beak size in Architeuthis suggests that squid of at least 2.69 m (99.9% prediction interval: 1.60–3.83 m) mantle length (ML) may be handled by large bull sperm whales but perhaps not females. Given the relationship of squid ML to standard (from tip of mantle to end of arms) and total (from tip of mantle to end of tentacles) length, the observed spread of individual lengths, along with a longest reliably measured ML of 2.79 m, purported squid of 10 m standard length and even 20 m total length are eminently plausible.