Introduction

Gonatus antarcticus was described by Lonnberg (1898) based on a stranded specimen near the Straits of Magellan (mm ML). He stressed that G. antarcticus difffered markedly form G. fabricii, which was the sole Gonatus species known at that time from the northern North Atlantic, by having greatly reduced marginal suckers, compressed hooks of arms I-III, and a little broader and differently shaped gladius. These characters stressed by Lonnberg may be due the comparison with the description of G. fabricii which was based on young individuals.

Diagnosis

A Gonatus with ...

• large-size, slender mantle (MW=17-18% ML), long tail (ca. 20% of ML) and soft body.
• long, narrow fins (FL=1/2ML), sagittate with round sides (FW=83% of FL).
  
• long stout tentacles and small tentacle clubs (TCL=16-17% of ML)
  
• tentacluar club with central large hook, middle-sized hook distal hook and 3-4 small proximal hooks with distal one largest and sizes decreasing proximally.