Olive nerite

Care at a glance

Overview

Keep it as a peaceful algae grazer for a freshwater or brackish tank, where it works over glass, rock, and wood without touching plants. It sits on the bottom and hardscape and does not school, so keep one or several to match the algae supply rather than for company. Hold the water hard and alkaline at a pH of 7 to 8.5 and 22 to 28 C, and cover the tank, since it will wander above the waterline and can dry out if it escapes. It will dot surfaces with hard white egg capsules, but these will not hatch into more snails in a normal tank, so there is no risk of a population boom. Feed algae wafers or blanched vegetables if the tank runs low on natural growth.

In the wild

Olive nerites come from brackish estuaries and coastal waters of the southeastern United States, the Gulf of Mexico, and the Caribbean, where they graze algae off hard surfaces in the intertidal zone. They are euryhaline and live across a wide salinity band from fresh to fairly salty, which is why they do equally well in a freshwater or a brackish tank. Give them stable, hard, alkaline water at a pH of 7 to 8.5 and a temperature of 22 to 28 C, with plenty of algae or biofilm to graze and a tight lid, since like all nerites they climb out of open tanks.

Good to know

This is a nerite snail in the family Neritidae, reaching about 2 cm, with a thick olive-green shell often marked by fine dark lines. It is the true olive nerite of the trade, correctly Vittina usnea, and it is widely sold under the older names Neritina reclivata and Neritina usnea. It is a separate species from the virgin nerite, Vitta virginea, which the two are often confused with. Like other nerites it lays hard white eggs but cannot complete its life cycle in freshwater, since the larvae need brackish or marine water to develop.

Did you know

It is the workhorse olive-green nerite most people picture when they hear nerite snail, yet it is regularly mislabeled. The genuine article is Vittina usnea from the American Gulf and Caribbean coast, not the superficially similar virgin nerite, so a tank of so-called olive nerites can actually be a mix of look-alike species.

Related species

• 

  Tiger nerite

  Vittina coromandeliana

  1 in (2.5 cm)5 gal (19 L)72–79°F (22–26°C)

• 

  Zebra Nerite

  Vittina natalensis

  1 in (2.5 cm)5 gal (20 L)66–84°F (19–29°C)

• 

  Virgin nerite

  Vitta virginea

  0.8 in (2 cm)5 gal (20 L)72–79°F (22–26°C)

• 

  Horned nerite

  Clithon corona

  0.6 in (1.5 cm)5 gal (19 L)72–79°F (22–26°C)

• 

  Marbled Limpet Nerite

  Septaria porcellana

  1.2 in (3 cm)5 gal (20 L)73–82°F (23–28°C)

• 

  Dusky Nerite Snail

  Neritina pulligera

  1.6 in (4 cm)5 gal (20 L)72–82°F (22–28°C)