Faunus ater is a species of brackish water snail with an operculum, an aquatic gastropod mollusk in the family Pachychilidae.
Faunus ater is the only species within the genus Faunus.[1]
The distribution of Faunus ater includes:
The periostracum is thick, and the color of the periostracum is dark brown or black.[1] The shell has about 20 whorls.[1] The apical whorls may be eroded in older snails.[1] The aperture is ovate and white.[1] The shell is unique among Cerithioidea, because it has two deep sinuses: an anal sinus which is close to the suture and an anterior sinus more forward in the aperture.[1] The height of the aperture is about one-fifth of the height of the shell.[1]
The height of the shell is usually 50–60 mm, but can be up to 90 mm.[1]
The operculum is oval, corneous and dark brown in color.[1] The snail has a broad snout.[1] The radula is large and is located in a correspondingly large buccal mass.[1]
This snail lives in slightly brackish water.[1] It has also been reported from freshwater.[1] It is the only pachychilid species that lives in brackish water; the other species in the family are freshwater snails.
The population density can reach up to 6700 snails per m2.[1]
This snail probably feeds by grazing.[1]
It is oviparous.[1] It probably has free-swimming larvae.[1]
This snail is used as a food source for humans in the Philippines and in Thailand.[1]