Red onion snail

Vittina semiconica

Also known as Red onion nerite, Orange cap nerite

FreshwaterBrackishSnail

Red onion snail (Vittina semiconica) — 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: 1 in (2.5 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 Southeast Asia and the western Pacific
Family: Neritidae

Overview

The red onion snail is a peaceful nerite bought for algae control rather than company; it is not a social animal, so keep one or add several to suit a larger tank, with no need for a group. It grinds steadily over glass, decor and broad leaves, clearing diatoms, green spot algae and biofilm while ignoring healthy plants. A spotless tank will not sustain it, so supplement with algae wafers, Spirulina and blanched vegetables such as cucumber or spinach. It mixes safely with fish, shrimp and other snails, but keep it away from snail-eaters. A mature tank of about 19 liters or more gives it enough to graze.

In the wild

Vittina semiconica lives in the lower reaches of coastal streams in Southeast Asia and the western Pacific, near the sea where the water carries plenty of minerals. Recreate that with a mature, well-filtered tank rich in grazing surfaces and stable, hard, alkaline water. Aim for about pH 7.0 to 8.2 and warmth from 22 to 28 degrees Celsius; in soft, acidic water the shell etches and thins. Regular small water changes and a secure lid keep it healthy and in the tank.

Good to know

Vittina semiconica is a nerite of the Neritidae, close kin to the tiger and zebra nerites, and reaches about 2.5 centimeters. Its shell shades from deep russet toward a paler apex, banded and dotted in dark markings. It lays small, hard white eggs on wood and stone, but the larvae need brackish or salt water, so the eggs never hatch into a plague of snails in fresh water.