Freshwater limpet (Ferrissia californica) care guide

Group
Snails
Other names
Ferrissia fragilis, Ferrissia wautieri, Fragile ancylid, Aquarium limpet
Family
Planorbidae
Origin
North America; spread to other countries including Europe, often with aquarium plants
Water
freshwater
Maximum size
0.2 cm
Temperature
10–28°C
pH
6.5–8
Hardness
5–15 dGH
Care level
beginner
Lifespan
about 1 years

Care

Ferrissia californica is a tiny freshwater limpet only about 2 mm long, with a cap-shaped shell that looks clear in aquariums and light to dark brown in the wild. It comes from North America and has been spread elsewhere. Ferrissia fragilis and Ferrissia wautieri are among many old names now treated as the same species. Hitchhiker: it usually arrives on plants, wood or with other livestock. It is harmless to fish, shrimp and plants; it simply grazes diatoms and biofilm from glass, leaves and stones. Some keepers see it as a pest because it can become numerous, but it does no damage and numbers drop when food is scarce. It is not usually sold as livestock. Identification: tiny pale oval dots stuck flat to the glass or plants that move slowly. They are not baby nerites, which have coiled shells, and not planaria, which glide and change shape. Control if wanted: feed less, remove by hand, and avoid snail-killing chemicals in shrimp tanks. Copper: copper-based medicines and some plant fertilisers are toxic to shrimp, snails and most other invertebrates. Never treat a tank holding them with copper, check the label of any fertiliser or medicine, and keep nets and buckets used for copper-treated tanks separate. Sources: Wikipedia (en.wikipedia.org/wiki/Ferrissiacalifornica). Checked October 2026.

Diet

Mainly diatoms and biofilm. It needs no feeding.

Breeding

A self-fertilising snail, so one is enough to start a population. It lays single eggs about 0.6 mm across, each holding one young. Eggs hatch in about seven days and the young mature in four to five weeks.

Compatibility and tank mates

Harmless to fish, shrimp, snails and plants. Many fish and snails, including assassin snails, eat it.

Last updated 8 October 2026. Community-edited care guide on Aquatic-Auctions.

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