SeafanEmergencies

Snail (grazer and sand)

Cerith snail

Cerithium spp.

Empty shell of a cerith snail (Cerithium spp.), not a live animal
Photo: Richard Parker, CC BY 2.0, via Wikimedia Commons
Group
Snail (grazer and sand)
Care level
Beginner
With corals
Reef safe

What does the cerith snail do in a reef tank?

Detritus, biofilm, algae and leftover food, including on and in the sand typical, check

With corals: Yes

How many should you keep?

Suitable from about 10 US gal typical, check

One US gallon is 3.785 litres and one UK gallon is 4.546 litres, so a "per gallon" rule depends on whose gallon it means.

What can go wrong?

Few; may breed

Photo note: Shell photo.

Which tankmates are risky?

Fish

Fish that may eat or harass it.

None of the fish in this guide is known to eat or harass it.

Other invertebrates

Invertebrates it may harm, or that may harm it.

Take care (2)

  • Blue leg hermit crabBlue leg hermit crabs kill snails to take their shells; give spare empty shells.
  • Large hermitsLarge hermitss kill snails to take their shells; give spare empty shells.

These checks follow the reasons fish and invertebrates clash: same species or genus, similar shape, mouth size, temperament, food, burrows, tank size and the order they are added. Individual animals differ; every source agrees on that.

Sources

  1. Chewy clean-up crew guideRead 21 October 2026, search summary only.

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