Faunus ater
Long, glossy black turret-shaped shell that looks more like a marine periwinkle than a freshwater snail. Tolerates fresh water indefinitely as long as hardness stays moderate — but won't breed unless given brackish conditions. The right algae crew snail for keepers who don't want a population explosion.
Black Devil Snail (Faunus ater) is an aquarium snail in family Pachychilidae, native to Brackish estuaries of Southeast Asia and the Pacific. Adults reach 5–8 cm; minimum tank 40 L. Target 22–28 °C, pH 7.0–8.5, 8–20 dGH, 4–12 dKH. Shell calcium demand: high. Diet: algae grazer / detritivore, Soft algae, biofilm, decaying plant matter, blanched zucchini. Calcium via cuttlebone for the long, conical shell. Breeding: Will not breed in pure fresh water (needs brackish for larval stage). A safe non-breeder for freshwater tanks. Algae-eating rating: 4/5. Plant-safe: Yes. Tank mates: Peaceful community fish, large enough to ignore. Avoid assassin snails and large loaches.
Care at a glance
Long, glossy black turret-shaped shell that looks more like a marine periwinkle than a freshwater snail. Tolerates fresh water indefinitely as long as hardness stays moderate — but won't breed unless given brackish conditions. The right algae crew snail for keepers who don't want a population explosion.
By Mike ElmiraUpdated 1 min read
Part of our complete planted-aquarium guide.
The parameters that decide whether black devil snail fits in your tank.
Pachychilidae
Algae grazer / detritivore
Soft algae, biofilm, decaying plant matter, blanched zucchini. Calcium via cuttlebone for the long, conical shell.
Will not breed in pure fresh water (needs brackish for larval stage). A safe non-breeder for freshwater tanks.
5–8 yrs
High
Yes
Brackish estuaries of Southeast Asia and the Pacific
Brackish estuaries of Southeast Asia and the Pacific
Tank-mate safety and the species this one is documented to thrive (or fail) alongside.
Direct answers to the questions search engines and AI assistants surface most often about this species.
Minimum tank: 40 L. Black Devil Snail (Faunus ater) reach 5–8 cm as adults.
Target 22–28 °C, pH 7.0–8.5, 8–20 dGH, and 4–12 dKH. Shell calcium demand is high, supplement with cuttlebone or a mineral stone if your water is soft.
Plant safety: Yes. Black Devil Snail are algae grazer / detritivore, Soft algae, biofilm, decaying plant matter, blanched zucchini. Calcium via cuttlebone for the long, conical shell.
Tank mates: Peaceful community fish, large enough to ignore. Avoid assassin snails and large loaches.
Algae-eating rating: 4/5. Soft algae, biofilm, decaying plant matter, blanched zucchini. Calcium via cuttlebone for the long, conical shell.
Will not breed in pure fresh water (needs brackish for larval stage). A safe non-breeder for freshwater tanks.
Typical lifespan: 5–8 years in a stable, well-maintained tank.
A planted tank is a system. Pair this snail with one entry from each other pillar to plan the whole scape.
