Faunus ater (Lava Snail, Devil Lava Snail or Black Devil Snail) 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.
This species is distributed throughout the archipelagos and large islands of the Indo-West Pacific region. It has been recorded from Thailand, Malaysia, Indonesia, New Guinea, Papua New Guinea, the Philippines and as far west as Sri Lanka. The snails we offer originate from Thailand.
The periostracum is thick, and the color of the periostracum is dark brown or black. The shell has about 20 whorls. The apical whorls may be eroded in older snails. The aperture is ovate and white. 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. The height of the aperture is about one-fifth of the height of the shell. The height of the shell is usually 50 – 60 mm, but can be up to 90 mm. The operculum is oval, corneous and dark brown in color. The snail has a broad snout. The radula is large and is located in a correspondingly large buccal mass.
Habitat and Ecology
This species is commonly found in the mouths and lower reaches of freshwater rivers where there is a brackish influence, shallow river estuaries, freshwater ponds and ditches. In Thailand this species has been recorded in fresh and brackish water creeks, streams and lagoons. In Java, this species occurs on mud flats, which run dry during low tide. In the Philippines this species has been collected at a depth of 1 – 1.5 metres in a clear brackish water lake, on sandy substrate, rocks and rocky shelves. Faunus ater feeds by grazing. They are also very useful in keeping tanks clean because they eat algae and rotted plant parts. They will also eat any kind of food tablets or flakes, as well as vegetables. It is oviparous. As far as we know it’s impossible to breed them in captivity.
Recommended water parameters for Faunus ater: temperature 23°C – 27°C, water hardness 10 – 25 dGH, acidity pH 7.5 – 8.0. We keep them equally successfully in brackish and fresh water. About 1 levelled teaspoon of marine salt per every 3 litres of freshwater works for them perfectly well.