Onykia robsoni

Brief diagnosis: A large Onykia with sagittate fins and round, blister-like 'warts' or papillae on the surface of the mantle, and 13-16 hook pairs on the tentacle clubs. 

Above: Tentacle clubs of Onykia robsoni (ML 260mm) from New Zealand. © Darren Stevens  

Key morphological features:

• Fins sagittate, their length 53-62% of ML at 156-370 mm ML, their width 51-70% of ML at 156-370 mm ML
• Gladius with long rostrum (ventral length 23-36% of GL; triangular in cross-section)
• Tentacle hooks with deep lateral grooves on the cusp 

This species is very similar to O. robusta in the shape of the fins but is separated by the structure of the skin (i.e., warts vs ridges), and the fewer pairs of club hooks (13-16 vs 16-18).

Above: 'Warts' or papillae on the mantle surface of a large Onykia robsoni (complex) specimen from New Zealand. © Darren Stevens 

Live animal

Onykia robsoni is not known to have been filmed or photographed alive yet.  

The type locality is off Angola at 16° 36'S, 11°20'E. This species complex occurs north of the southern subtropical convergence, off southwestern Australia, New Zealand and southern Africa, morphologically similar specimens have been taken from the Gulf of Mexico and off Bermuda in the North Atlantic (Kubodera et al. 1998). It is also reported off the southwestern coast of South America.

• Moroteuthis robsoni