Ancistroteuthis is monotypic. Kubodera et al. (1998), however, briefly described a new form of the species from the Central Atlantic. A. lichtensteinii is best known from the Mediterranean Sea. There, males mature at about 200 mm ML and the species reaches a maximum size of 300 mm ML (Kubodera et al. 1998). This species is very similar to species of Onychoteuthis but is most easily distinguished by the absence of a visible gladius along the mid-dorsal line and the absence of photophores.

Brief diagnosis:

An onychoteuthid ...

• without gladius visible beneath skin in dorsal midline.
• with 8-10 occipital folds.
• without suckers on distal portion of club before terminal pad.
• without photophores.