Steenstrup, 1857
Description of generic characters
Juvenile. Mantle long, slender, muscular with distinct marginal lobes; fins terminal and small (30-35% of the mantle length), longer than wide, rounded and continuous posteriorly; fin insertions broad anteriorly.
Head circular in cross section, slightly wider than width of mantle; eyes large and prominent; funnel locking cartilage simple, straight and long.
Mantle, head, and aboral surface of arms are covered with silvery white fibrous tissue, which is absent from posterior margin of the head.
Arms long to very long, 40-60% and even 100% of mantle length; arm formula 4=3=2>1; tentacle clubs long, expanded amnus with four rows of suckers, the median two rows with greatly enlarged suckers; 65-100 minute closely packed suckers irregularly clustered proximal to manus; dactylus narrow and elongated, with four rows of suckers becoming minute distally.
Size
Smallest specimens known are 45 and 57 mm mantle length, a larger young was 167 mm ML. Adults attain very large sizes, up to 3 or 4 meters ML.
Depth range
Uncertain, but small specimens (45 and 57 mm ML) from predator stomach content were estimated to be captured in the upper few 100 meters.
Distribution in the North Sea
Since 1860 a dozen stranded or captured adult or non-juvenile Architeuthis dux have been reported from the NW North Sea (Collins, 1998); there are several records from the Danish coast (Muus, 1959). There are no records of juveniles from the area.
World distribution
Worldwide, most abundant records from the N atlantic Ocean (Newfoundland, Norway), SW Pacific Ocean (New Zealand), NW Pacific Ocean (Japan) and the Southern Ocean.
[After Roper, 1992 in Sweeney et al., 1992]