Amphidromus inversus
Amphidromus inversus is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Camaenidae.
Like most members of the subgenus Amphidromus, it is chirally dimorphic: within the same populations, both dextral and sinistral individuals co-exist. This is one of the very few cases of genetic antisymmetry known in nature. Among the subgenus Amphidromus, A. inversus stands out because since c. 2004, it has been the focus of studies aimed at understanding the evolution of chiral dimorphism. Most of these studies have taken place on the Malaysian island of Kapas.
Subspecies
Amphidromus inversus albulus Sutcharit & Panha, 2006Amphidromus inversus andamensis Amphidromus inversus annamiticus Amphidromus inversus fureyi Thach & F. Huber, 2021Amphidromus inversus inversus Amphidromus inversus koperbergi Laidlaw & Solem, 1961Distribution
Sumatra, Peninsular Malaysia, ThailandDescription
This Helix possesses a conico-acuminate shell that is sinistral and whitish, displaying reddish streaks and a band, and features a reflected lip.This is a somewhat larger Helix and it exhibits a dextral coiling, sharing similarities in shape and size with Helix recta, but differing in color and the coiling direction of its whorls. The apex of this shell is acute. Its eight whorls coil sinistrally and are marked with reddish streaks drawn obliquely along their length; a broad pale reddish band encircles the shell near the base. The aperture is ovate and white. The outer lip appears pure white and reflected; the inner lip presents the same color, while the whorl penetrating the aperture is brown.
The shell is oblong-ovate and rather thick, most frequently coiling sinistrally. It comprises seven convex, smooth whorls with a reflected lip. Its base color is whitish, overlaid with stains and irregularly longitudinal streaks of burnt brown. The lip appears white, while the columella and outer edge of the lip exhibit a purplish-brown hue.