Atlanta fragilis Richter, 1993
This is a medium sized dextrally shelled, pelagic snail, 0.8 cm in diameter with very large eyes and a single swimming fin. It is large, strongly flattened and keeled. The spire is very small, and like the rest of the shell, colourless. The operculum has a very small spire. It is a carnivore, predating on relatively large zooplankton. This species occurs in warm waters of the Atlantic Ocean (Atlanta fragilis).
Taxonomic Description [after Richter, 1993]
The shell is strongly flattened and has 6 whorls. The spire is small, without sculpture but with a clear suture. The umbilicus is relatively narrow and the keel is high. The fifth whorl is separated from the fourth one by a deep penetration of the keel in between the whorls. The shell is completely colourless, very thin and fragile. The eye lens is very large (twice as large as in Atlanta peroni). The radula formula is 2-1-1-1-2 with 70 transverse rows, the median teeth has a large median cusp, the additional teeth are smaller than the lateral teeth. In males the additional teeth are shortened. The laterals are broad and short.
Shell diameter up to 8.1 mm.
The juveniles have a small dextrally coiled shell. A special description is not available.
In this species the sexes are separate.
This species is an epipelagic carnivore.
This species occurs in the tropical central Atlantic.
Atlanta fragilis Richter, 1993: 191, pl. 1, fig. 2, pl. 2, fig. 6, pl. 4, figs. 16, 17, 20.
Holotype SMF 309762 in SMFM. Paratypes: SMF 309763/5 in SMFM.
Type locality: Meteor 51 stat. 94, 0-50m depth.