Pneumoderma atlanticum souleyeti

Pneumoderma atlanticum (Oken, 1815) subsp. souleyeti (Pelseneer, 1887c)


This is a naked pelagic snail, about 0.6 cm long. It is round, with a slightly transparent, usually pigmented skin. The wings are small, relative to the posterior and lateral footlobes. The buccal mass has two lateral arms, each with up to 80 suckers. It lives in the Atlantic, Mediterranean and Pacific Oceans, in the upper water layers, although it is never abundant (Pneumoderma a. souleyeti).

Taxonomic Description

The body is round, small. The skin is slightly transparent, with numerous glandular tubercles. Visceral mass fills nearly the whole body. Head relatively large, clearly separated from the body. Median footlobe rather long, lateral lobes well developed and nearly parallel. A median foot tubercle is present. The lateral sucker arms were originally described as extremely long, but they are normal in length when not fully evaginated. Suckers, about 50 to 80 in number, on each arm. The most distal suckers are smaller than the other ones, sucker stalks normal in length. Lateral and posterior gills present, but rather simple in composition, showing no fringes. The posterior gill (Pneumoderma a. souleyeti line drawing) is only a small ring with four short rays. The buccal organs resemble those of the forma atlanticum. The hooks are numerous, about 80 in number. They are short, robust and placed in slender, deep sacs. The Pneumoderma a. souleyeti radula formula is 3-0-3 or 4-0-4. The teeth resemble those of the forma atlanticum in shape. The tentacles are extremely small which is usual for this species. The jaw consists of 30 slightly curved denticles.
Body length up to 6 mm.


A special description is not available.


This species is a protandric hermaphrodite.


This species is a carnivore.


It is found in the Mediterranean, Atlantic and N-Pacific Oceans, see the Pneumoderma a. souleyeti map.


Pneumonoderma souleyeti Pelseneer, 1887: 31, pl. 2, fig. 6.
Holotype not found in BMNH, u.s.
Type locality: 35°13'N 154°43'W. Coll.: CCHE, stat. 254.