Atlanta plana Richter, 1972b

Overview

This is a medium sized, dextrally shelled, pelagic snail, 0.4 cm in diameter with large eyes and a single swimming fin. The shell is large, strongly flattened and keeled. The faintly violet spire is small. The operculum has a spiral line of radial dents (Atlanta plana 1, Atlanta plana 3). It is a carnivore predating on relatively large zooplankton. This species occurs in the Indian Ocean.

Taxonomic Description [after Richter, 1987]

The shell is large and strongly flattened. The spire is small(Atlanta plana protoc 2). The suture is deep and clearly visible. A very faint spiral sculpture is seen on the two inner most whorls of the spire. The spire is faint violet, the keel base is darker. The last whorl is very flat. The aperture is inflated. There is no decalcification in the spire (Atlanta plana 2, Atlanta plana). The operculum (type B) is slender oval, oligogyre with a small nucleus with a spiral line of radial dentation (Atlanta plana operculum, Atlanta plana operculum1). The eyes (type A) have a cylindrical pigment mantle and a triangular dorsal window. The radula is large, narrow-triangular with large teeth; the median tooth is broad rectangular with a strong cusp and lateral wings; lateral teeth are unicuspoid with a remarkable high basal plate; additional teeth in one pair are of different size and short. There is no sexual dimorphism.
Shell diameter 4 mm.

Juveniles

The juveniles have a small, dextrally coiled shell. The Atlanta plana protoconch I is smooth, the protoconch II shows 3 clear spiral lines. The Atlanta plana veliger also has lines on the underside of the whorl and the sides of the whorls are rounded. The protoconch I is clearly elevated above the protoconch II. In Atlanta plana juv. specimens the groove of the keel is already seen on the third whorl.

Reproduction

In this species the sexes are separate.

Ecology

This species is a carnivore and epipelagic.

Distribution

This species occurs in the Indian Ocean, a map is not given as the records are not well documented, see the Atlanta plana map.

Types

Atlanta plana Richter, 1972: 90, figs. 4, 6, 8.
Holotype: SMFM 223055. Paratype: SMFM 223056.
Type locality: Indian Ocean. Coll.: CMEE.

Kingdom Animalia
Phylum Mollusca
Class Gastropoda
Subclass Streptoneura
Order Mesogastropoda
Superfamily Atlantacea
Family Atlantidae
Genus Atlanta
Species Atlanta plana

Status in World Register of Marine Species

Not included in WoRMS database

Scientific synonyms and common names

Atlanta plana Richter, 1972b

Synonyms

Atlanta inflata part Tokioka, 1961: 286
Atlanta plana n. sp. Richter, 1972b: 90

Gasca, R. S., 1992. Heteropodos de la bahia de la Ascension, Quintana Roo. In: Navarro, D and Suarez-Morales (eds). Diversidad biológica en la reserva de la biosfera de Sain Ka'an Quintana, Roo, México 2: 123-127.

Richter, G., 1972b. Zur Kenntnis der Gattung Atlanta (Heteropoda: Atlantidae). Arch. Molluskenkunde 102(1-3): 85-91, 11 figs.

Richter, G., 1973b. Zur Stammesgeschichte pelagischer Gastropoden. Natur und Museum 103(8): 265-275, 4 tabs, 9 figs.

Richter, G., 1974. Die Heteropoden der 'Meteor' Expedition in den Indischen Ozean 1964/65. 'Meteor' Forschungserg. (D)17: 55-78, 8 figs, 3 pls.

Richter, G., 1987. Zur Kenntnis der Gattung Atlanta, 3. Atlanta inflata, A. helicinoides, A. echinogyra und A. plana (Prosobranchia: Heteropoda). Arch. Moll. 117(4-6): 177-201, 1 tab., 7 pls.

Seapy, R. R., 1990d. Sampling requirements for epipelagic heteropod molluscs. Amer. Malac. Bull. 8(1): 45-52.

Seapy, R. R., 1990e. The pelagic family Atlantidae (Gastropoda: Heteropoda) from Hawaiian waters: A faunistic survey. Malacologia 32(1): 107-103.

Tokioka, T., 1961. The structure of the operculum of the species of Atlantidae (Gastropoda: Heteropoda) as a taxonomic criterion, with records of some pelagic mollusks in the North Pacific. Publ. Seto mar. biol. Lab. 9(2): 267-332 (art. 15, pp. 1-86).

No distribution map was available at OBIS the last time we checked. Retry now.

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