Zebra thorn snail

Clithon diadema

Also known as Diadem thorn snail, Zebra horned nerite

FreshwaterBrackishSnail

Zebra thorn snail (Clithon diadema) — The Wet Spot Tropical Fish · Used with permission

Care at a glance

Temperature: 72–82°F (22–28°C)
pH: 7.0–8.2
Adult size: 0.8 in (2 cm)
Minimum tank: 5 gal (19 L)
Temperament: Peaceful
Social behavior: Solitary
Swim level: Bottom
Difficulty: Easy
Breeding: Hard
Rarity: Rare
Origin: Coastal streams of Indonesia and the Philippines
Family: Neritidae

Overview

The zebra thorn snail is a striking little nerite kept for algae control rather than company; it is not social, so keep one or add several to a larger tank as the algae supply allows, with no group needed. It moves slowly over glass, decor and broad leaves, grazing algae and biofilm and leaving healthy plants alone. Supplement a clean tank with algae wafers and Spirulina so it does not go hungry. It is completely peaceful and safe with fish and shrimp, though snail-eating fish should be kept out. A mature tank of about 19 liters or more suits it well.

In the wild

Clithon diadema grazes stones and roots where island streams of Indonesia and the Philippines run down to the coast, in hard, clean, mineral-rich water. Recreate that with a mature tank full of grazing surfaces and stable, hard, alkaline water, about pH 7.0 to 8.2, kept warm at 22 to 28 degrees Celsius. Soft, acidic water pits and thins the shell, so keep the mineral content up. A firm-fitting lid stops it climbing out above the water.

Good to know

Clithon diadema is a thorn nerite of the Neritidae, a little over 2 centimeters across, with a glossy black-and-gold striped shell and a row of sharp spines along the front edge. The spines deter predators and can regrow if broken, provided the water supplies enough minerals. This species always carries its thorns, unlike some relatives that may be smooth or spined.

Did you know

Its species name diadema means crown, for the ring of thorns around the shell, and because the larvae must have salt water to grow, this crowned grazer can never overrun a tank the way common pond snails do.