A large, peaceful apple snail available in many bright shell and body colors that helps clean algae and detritus without destroying live plants.
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Educational only. KinStation content is reviewed by licensed veterinarians but cannot replace an in-person exam. Always consult a licensed veterinarian or board-certified specialist for diagnosis, treatment, or any decision affecting your pet's health.
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Shell grows to about 4-5 cm (1.5-2 in) across; among the larger commonly kept aquarium snails.
Lifespan
1–3 years
Social needs
solo
Native region
South America (Amazon River basin)
Origin
New World
Climate
🌴 Tropical
Water type
💧 Freshwater
Family
Ampullariidae
Genus
Pomacea
Part of the Snails
Peaceful freshwater aquarium snails kept as algae grazers, detritus cleaners, and colorful display animals. Most need stable, calcium-rich water for shell health and are highly sensitive to copper.
From the minimum an animal needs to be kept humanely, up to the ideal setup. Bigger is almost always better — minimums are floors, not targets.
Photo coming soon
Minimum
Cycled FW tank
5+ gal cycled, single snail
Mystery snails (Pomacea bridgesii) are peaceful FW grazers — need 5+ gal per snail, hard water (GH 8–15) for shell health, calcium supplementation (cuttlebone), and a tight-fitting lid (escape artists).
Photo coming soon
Recommended
Planted community tank
10+ gal planted community
Planted tank with algae for grazing plus blanched veg (zucchini, spinach). Temperature 21–28 °C. They lay air-exposed egg clutches above the waterline — keep ≥ 2 in air gap.
Photo coming soon
Ideal
Heavily planted breeding tank
20+ gal heavily planted
Heavily planted tank with hard water, calcium supplement, and varied plant/algae food. Will breed readily — buyers can be lined up via local aquarium clubs.
Life & growth stages
How this animal changes through its life — each stage often has its own care, diet and space needs.
Photo coming soon
Larva
Most marine invertebrates hatch into microscopic planktonic larvae (such as the zoea of crustaceans or the bipinnaria/veliger of echinoderms and mollusks) that drift and feed in the water column. The larva looks nothing like the adult and undergoes major reorganization.
Photo coming soon
Juvenile
After settling out of the plankton, the juvenile takes on a recognizable miniature of the adult body plan — a tiny shell, a small star, or a translucent shrimp. Crustaceans grow by molting, shedding the exoskeleton to enlarge.
Adult
Adults reach full size and reproductive maturity with the species' mature shell, shape, or coloration. Many continue to molt or grow throughout life, and some show sex differences in size or claw/appendage shape.
Color & pattern variants
Natural variants occur in the wild; selectively bred (man-made) variants were developed in captivity.
Mystery snails need a fully cycled freshwater tank of at least 19 L (5 gallons), with 38 L (10 gallons) or more recommended since they produce noticeable waste and benefit from the stability of a larger volume. Keep temperature at 20-28 C (68-82 F), with 24-26 C (75-78 F) ideal; they become sluggish and stop eating below about 18 C (65 F). Aim for pH 7.0-8.0 and moderate-to-hard water with adequate calcium, as soft or acidic water erodes the shell.
Leave a few centimeters of air gap above the water and a secure lid: mystery snails breathe air through a siphon, lay their pink egg clutches above the waterline, and will crawl out of an uncovered tank. Provide live plants, smooth decor, and a calcium source such as a cuttlebone or crushed coral to keep the shell strong.
Substrate
Smooth gravel or sand works well; mystery snails graze surfaces rather than burrow, so any non-sharp substrate is fine. Crucially, keep the water column rich in calcium (a cuttlebone or crushed coral in the substrate) to prevent shell pitting and erosion.
Equipment & setup
A cycled, gently filtered tank of at least 5 gallons per snail, heated to 68-82F. Keep pH and KH on the harder, more alkaline side, and always maintain a few inches of air gap above the waterline with a tight lid, since they breathe air via a siphon and lay egg clutches above the water.
Diet
Mystery snails are omnivores that scavenge algae, biofilm, and leftover food, but a tank rarely supplies enough to sustain them, so they should be fed regularly. Offer algae wafers and sinking pellets plus blanched vegetables such as zucchini, cucumber, spinach, kale, and lettuce; calcium-rich greens and supplements support shell growth.
Unlike some apple snails, Pomacea diffusa generally leaves healthy live plants alone, eating mainly soft algae, detritus, and decaying plant matter. Provide a steady calcium source (cuttlebone, crushed coral, or a supplement) and remove uneaten food promptly to protect water quality given their relatively high waste output.
Behavior & temperament
Mystery snails are slow, peaceful, and undemanding, spending the day gliding over glass, plants, and decor grazing for food. They are happy alone or in small numbers and coexist well with peaceful fish, shrimp, and other snails; just avoid known snail-eaters such as some loaches, pufferfish, and assassin snails. They do not need a companion to thrive, though they are interesting to watch in a small group.
Enrichment comes from a varied, well-planted environment with surfaces to graze and the air gap they need to surface and breathe. They are active and inquisitive for a snail, often extending their long siphon to the surface. If a male and female are present they will breed readily, depositing distinctive cocoon-like pink egg clutches above the waterline, which can simply be removed if offspring are not wanted.
Health
The most common health problems involve the shell. Insufficient calcium or low/acidic pH leads to pitting, thinning, cracks, and white erosion at the spire; correcting calcium and keeping pH stable and slightly alkaline restores new growth. Shells can also be damaged by rough handling or being dropped. Like all snails they are highly sensitive to copper, so avoid copper-based medications.
Other issues include lethargy or failure to eat in water that is too cold, and stress from poor water quality given their heavy waste load. Prevent problems with stable, calcium-rich, fully cycled water, steady warm temperatures, secure but not airtight covering so they can breathe air, and gentle handling. Consult an aquatic veterinarian before medicating any tank that houses snails.
This information is general guidance and not a substitute for advice from a qualified aquatic veterinarian.
Tips, DIY & hacks
They are voracious algae and biofilm grazers and excellent leftover-food cleaners; supplement with blanched vegetables and calcium-rich foods. Avoid copper-based medications and plant fertilizers, which are lethal to snails, and scoop floating snails to sniff-check rather than assume death.
