Atlanta inflata Souleyet, 1852a
Overview
This is a small dextrally shelled, pelagic snail, 0.2 cm in diameter with large eyes and a single swimming fin. The shell is large, strongly flattened and keeled. There are 7 whorls. The spire is large rather low, it shows spiral sculpture. The operculum is monogyre. It is a carnivore predating on relatively large zooplankton. This species occurs in warm waters of all oceans (Atlanta inflata adult, Atlanta inflata 1).
Taxonomic Description [after Richter, 1987]
Shell very small, whorls close together (Atlanta inflata 2). Spire relatively low, with fine spiral sculpture on the upper and underside. Mediterranean specimens have a smooth underside. Inner whorl-sides in spire decalcified. The spire is violet or yellow/brown, and the keel base is dark. The body whorl is laterally compressed, slender oval, only the aperture is widen (Atlanta inflata living). The operculum (type C) is monogyre slender oval, its underside is convex or concave. The eyes (type A) have a cylindrical pigment mantle with a dorsal window. The radula shows sexual dimorphism: in males it is broadly triangular with a rapid increase in width; dumb-bell shaped median tooth with reduced central cusp; and the lateral teeth are very broad and flat, unicuspoid; the additional teeth are long and slender; in females the radula is ribbon-shaped with reduced median teeth; the lateral teeth are unicuspoid, sometimes with an additional lateral cusp; the addition teeth are relatively short.
Shell diameter up to 1.5 mm, not reached in this illustrated Atlanta inflata juvenile specimen.
Juveniles
The juveniles have a small, dextrally coiled shell. There are spiral lines on the yellow, brown or violet larval shell. The velum is first bi- and later 6 lobed, the lobes are broad, rounded. The Atlanta inflata veliger2 shell shows about 9 slightly irregular spiral lines. The Atlanta inflata protoconch I is smooth, the protoconch II shows 2 to 3 spiral lines, in some Atlanta inflata protoc2 onchs these lines are irregular. The veliger is characterised by the laterally, somewhat compressed last whorl. Spiral lines visible over the whole shell are branching and irregular.
Reproduction
In this species the sexes are separate.
Ecology
This species is carnivorous and epipelagic.
Distribution
This species occurs in the warm waters of all oceans, see the Atlanta inflata map.
Type
Atlanta inflata Souleyet, 1852: 378 (1841): 19, figs. 8-21.
Syntypes: 2 spec. with dissolved shell of which separation is impossible, MHNP.
Type locality: China Sea. Coll.: Eydoux and Souleyet.