Cycloteuthis sirventi

The species occurs in the tropical to polar western Atlantic Ocean.

[3] The fins are long and elliptical shaped, taking up about 80% of the overall mantle length.

The tentacles are long and robust, their clubs bearing four rows of suckers.

[3] Later, in 1921, Thiele created the Parateuthis genus based on a larval Oegopsida captured in the Antarctic Ocean.

[3][5] However, this genus holds no connection to Joubin's Parateuthidae family.