The Patagonian squid is a small species and has a mantle length of 10 to 15 cm (4 to 6 in) and a weight of between 75 and 150 grams (2.6 and 5.3 oz).

The tentacles are long and slender, each terminated by a club-shaped "manus" with small, narrow suckers at the edge and slightly larger ones at the centre.

Prey items are caught by the tentacles, grasped and moved to the mouth with the help of the arms, and then chewed by the horny beak.

Fragile egg masses some 25 mm (1 in) long containing about 15 embryos have been found among stems of the kelp Lessonia trabeculata, particularly in places where the algae have been heavily defoliated, suggesting that a semi-protected environment with adequate water movement is desirable.

In the Atlantic Ocean there is a dedicated fishery in the Falkland Islands/Islas Malvinas where it is an important target species taken from over the Patagonian Shelf.