The classic reef-tank grazer, and for good reason. The Astrea Snail wears a cone-shaped shell with a textured, ridged surface — often crowned with small spiky projections — that gives it a rugged, sculptural look against the rockwork. What it lacks in flash it makes up for in pure algae-eating efficiency.

These are some of the most reliable film-algae grazers in the hobby, working glass and rock surfaces relentlessly and reaching into spots larger snails miss. Their smaller footprint makes them ideal for keeping nuisance algae in check without disturbing corals or rockscape. Peaceful to a fault, they'll never bother a frag or a tankmate.

One honest note worth knowing: unlike Trochus snails, Astreas struggle to flip themselves back over if they topple onto the sand. It's worth a quick scan during feedings to set any stragglers upright — a small habit that keeps your crew healthy and working.

Affordable, hardy, and endlessly productive, the Astrea remains a foundational pick for nano tanks and full reefs alike.

Quick facts

• Scientific name: Astraea tecta
• Max size: ~1 inch
• Diet: film algae, diatoms, and cyanobacteria grazer
• Temperament: peaceful
• Reef compatibility: reef-safe
• Care level: easy
• Parameters: 76–80°F, salinity 1.024–1.026, stable pH

Drip acclimate over 1–2 hours before introducing to your display. Like all marine invertebrates, sensitive to copper and sudden swings in salinity.