Mantle thin, membranous in larvae and juveniles, leathery in adults, cup-like, slightly rounded behind in larvae, subacute in juveniles and adults. Two-4 (rarely 1 or 5) small, conical cartilaginous tubercles at sites of mantle-to-funnel fusion (at ML >25-30 mm, one tubercle at 10-20 mm). Head small, short. Eyes in larvae on short stalks, in juveniles semi-settled, elongate, at ML >5 cm not stalked, globular. Eye diameter in adults 14-18% ML. Fins petaloid in larvae, inverted-heart-shaped in juveniles, elongated-oval or lancet-shaped in adults, fin length to 60% ML. At ML >25-30 mm anterior margins of fin go onto mantle sides anterior to lanceola; posterior end of fins do not extend beyond end of lanceola. Arms short, with 2 rows of suckers, 3rd arms longest. In mid-parts of 2nd and particularly 3rd arms some enlarged suckers with smooth or barely dentate rings. Tentacles long in larvae, rather short in adults, with thick stalks, not autotomized. Tentacular stalk in specimens ML <25-30 mm with 4 rows of small suckers along entire length, in adults proximal third without suckers, rest with 3 oblique rows. Four rows of suckers on club, central one somewhat larger than marginal, rings dentate, with 26-32 teeth. Rear sides of lanceola straight, tail length from site of maximal lanceola width to gladius end 20-22% ML. Medial component of funnel organ with three papillae: one central conical and two lateral spatulate. No funnel valve.
Three eyeball photophores, a small sickle-shaped one in the concavity of a large semilunar one, and the smallest elongate, near acute end of sickle. Large arm photophore on ends of all arms in mature females. Ends of 1-2nd arms modified in males, with 2-4 rows of specialized suckers with reduced apertures. Color in larvae clear, semitransparent, with many oval dark chromatophores forming a longitudinal stripe along dorsal mantle. Adults dark, with numerous moderately spaced small oval chromatophores. ML up to 20 cm.
Larvae may be distinguished by many oval chromatophores forming longitudinal stripe along the back. In larvae first eye photophore appears at ML approx. 5 mm, second at 15-20 mm, third at approx. 50 mm.
Three species in Atlantic Ocean, 2 in the South Atlantic. Teuthowenia pellucida distributed around the Southern Subtropical Convergence in the Atlantic, southern part of the Indian Ocean and SW Pacific. Teuthowenia maculata (Leach, 1817), in the tropical East Atlantic, differs by having only one tubercle at the mantle-to-funnel fusion site, gladius tail length 23-29% ML, and large club suckers with 19-26 teeth.