Zebra Nerite Snail

Nerite snails are known for how well they clean green algae and biofilm off aquarium glass, stones and leaves. The zebra nerite, with its black-striped shell on a golden-yellow base, is one of the most decorative; relatives such as the "olive," "horned" and "tiger" nerites need similar care.

Its biggest advantage: it does not reproduce in fresh water. Unlike many snails, it does not overrun the aquarium.

It lives on the coasts of East Africa, in estuaries where fresh water mixes with the sea and in mangrove swamps. Its larvae develop in brackish and salt water.

• Volume: 20 liters or more; 1–2 nerites per 20 liters, depending on the amount of algae.
• Water: pH 7 or above, moderately hard to hard water. Soft, acidic water erodes the shell; white pits and peeling appear on the shell.
• Lid: nerite snails can climb above the waterline and out of the aquarium. A lid, or keeping the water level slightly low, is needed.

Its main food is algae and biofilm. When algae runs low, it should be fed spirulina/algae tablets and blanched vegetables (zucchini, spinach); a starving nerite weakens. Calcium in the water is important for shell health.

Completely peaceful; it does not harm plants and leaves fish and shrimp alone. A nerite that flips over may not be able to right itself; turn over any that stay upside down in the same spot for a few days.

Good companions: almost any peaceful community; shrimp tanks in particular.

Avoid: snail-eating species (clown loach, large cichlids, puffers), medications containing copper.

Nerite snails have no social needs; they also live on their own. Numbers are determined by the amount of algae in the aquarium: the general rule is 1–2 nerites per 20 liters.

Excess nerites go hungry when the algae runs out; once the algae is gone, tablets and vegetables should be given. Since they do not reproduce in fresh water, their numbers do not increase on their own, but in aquariums with more than one nerite, white egg capsules may appear on hard surfaces.

Females deposit small, white egg capsules like sesame seeds on hard surfaces (stones, roots, glass). These eggs do not hatch in fresh water, or the larvae do not survive; there is no lasting reproduction in the aquarium. The white dots may spoil the look, but they wear away over time.

• Shell erosion: low pH and low hardness. Keep the pH above 7; add coral sand or cuttlebone if needed.
• Jagged shell edge: calcium deficiency.
• Copper and many antiparasitic medications are lethal to snails.

Cannot be distinguished externally. Individuals that lay eggs are female.