Stomatella Snail

Stomatella snails are recognized by their small, flat, ear-shaped shells and by the large foot that extends backward and partly covers the shell. Their color varies among gray, black, brown and speckled tones; they grow to about 1–2 cm. Most enter aquariums on their own with live rock, and some sellers also sell them as cleanup crew. In the hobby they are mostly referred to as Stomatella varia or S. impertusa; but since these species cannot be reliably told apart from the outside, they are described here at the genus level. When threatened it sheds the rear part of its foot; while the wriggling piece distracts the predator the snail escapes, and the lost part regrows within a few weeks. It is distinguished from young abalones by the lack of a row of holes in its shell.

• Any mature reef or fish-only aquarium larger than 20 liters; live rock with plenty of algae.
• Salinity specific gravity 1.023–1.026, pH 8.1–8.4, temperature 24–27°C.
• Reef safe; it does not touch corals.
• Copper-based medications are lethal; it should not be handled roughly when moved.

Herbivorous; it grazes the microalgae film and biofilm on the glass and rocks. If algae become scarce as the population grows, it can be supplemented with algae granules and nori.

Nocturnal; after the lights go out it moves quickly across the glass. Since hermit crabs and large shrimp can prey on it, it reproduces best in aquariums with few of these animals.

Good companions: clownfish, gobies, blennies, cardinalfish; corals, other snails.

Avoid: hermit crabs, boxer shrimp, arrow crabs, triggerfish and pufferfish, large wrasses.