Astrea Snail

Astraea tecta

Animalia›Mollusca›Gastropoda›Tegulidae

📍 Caribbean reefs and rubble zones

One of the best reef algae-eating snails — effective grazer of microalgae and diatoms on rock and glass. Conical shell with star-like ridges. Cannot right itself if flipped, so monitor after storms of flow.

Size2"

Min Tank10g

peaceful

Zoneall

Care Guide

Diet

Astrea snails are herbivorous grazers that feed primarily on film algae, diatoms, and microalgae found on rocks and aquarium glass. They do not require supplemental feeding in established reef tanks with adequate algae growth, but in newer or heavily cleaned tanks, offer dried seaweed sheets or algae wafers 2-3 times weekly. They will not consume large macroalgae or detritus like some other snails.

Behavior

Astrea snails are slow, methodical grazers that spend most of their time crawling along surfaces in search of microalgae. They are completely peaceful and nocturnal, becoming more active during evening hours. A critical vulnerability: they cannot right themselves if flipped over, so monitor tank conditions after strong water flow or storms, as they will die if stuck upside-down for extended periods.

Breeding

Breeding Astrea snails in captivity is extremely rare and not reliably documented in home aquariums. They are broadcast spawners that require specific larval conditions and planktonic food sources difficult to replicate in closed systems. Hobbyists should not expect reproduction and should source specimens from established suppliers.

Tank Mates

Nerite Snail

Similar algae-grazing habits and peaceful temperament; no competition or aggression

excellent

Ocellaris Clownfish

Reef-safe fish that ignores snails; compatible with Caribbean reef biotope

excellent

Pistol Shrimp

Peaceful invertebrate that shares reef habitat; may occasionally startle snail but not aggressive

good

Fire Shrimp

Reef-safe scavenger with no predatory interest in snails; compatible water parameters

excellent

Lawnmower Blenny

Algae-grazing fish that shares ecological niche; both benefit from biofilm-rich environments

good

Common Diseases

Shell Erosion

Symptoms

Pitting, chalky appearance, or thinning of shell; reduced shell integrity

Treatment

Maintain stable pH 8.1–8.4 and adequate calcium levels (400–450 ppm); perform regular water changes to ensure mineral availability

Parasitic Infection

Symptoms

Lethargy, withdrawn behavior, failure to graze, visible parasites on foot or shell

Treatment

Quarantine affected snail; perform freshwater dips (5–10 minutes) or use copper-free parasite treatments; improve water quality and reduce stressors

Starvation

Symptoms

Inactivity, weight loss, failure to emerge from shell, slow or no grazing

Treatment

Ensure adequate algae growth through moderate lighting; supplement with algae wafers or dried seaweed if natural food sources are insufficient

Injury from Flipping

Symptoms

Snail stuck upside-down, unable to right itself, prolonged immobility

Treatment

Manually flip snail upright immediately if discovered; reduce water flow intensity and remove sharp décor that may cause tipping; monitor for secondary infections