Atlanta affinis Tesch, 1906a
Overview
This is a medium sized dextrally shelled pelagic snail, 0.4 cm in diameter with very large eyes, a single swimming fin. It is large, strongly flattened and keeled. The spire is oblique with radial lines; the shell is colourless (Atlanta affinis). The operculum has a very small spire. It is a carnivore predating on relatively large zooplankton. This species occurs in warm waters of the Indian Ocean and Indo-Malayan waters (Atlanta affinis lateral).
Taxonomic Description
The shell is faint yellow with 6.5 whorls. The spire is oblique and rounded with radial sculpture. It is relatively large. The keel penetrates half a whorl distance in between the preceding whorls. The eyes are small of the type B. The thin transparent operculum is micro-oligogyre. The aperture is small oval. The radula is very large.
Shell diameter up to 4 mm.
Juveniles
The juveniles have a small dextrally coiled shell. A special description is not available (Atlanta affinis 1).
Reproduction
The sexes are separate in this species.
Ecology
This species is carnivorous and epipelagic.
Distribution
This species occurs in the W-Indian Ocean and Indo-Malayan waters.
Types
Atlanta affinis Tesch, 1906: 53, pl. 7, figs. 9-10.
Syntypes 19 specimens in ZMAN.
Type locality: Between Bahuluwang and Tambolungan, 1°4.5'S 127°52.6'E, 2°40'S 128°37.5'E, 3°32.5'S 124°15.5'E, 5°40.7'S 120°45.5'E, South of Lucipara Is. (Indonesia).