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SnailbeginnerFreshwater

Giant Ramshorn Snail

Marisa cornuarietis

AnimaliaMolluscaGastropodaAmpullariidae

📍 South America

Ask Finn

The Giant Ramshorn (Colombian Ramshorn) is a large, impressive snail with a distinctive flat, coiled shell striped in brown and cream — reaching up to 5 cm (2.0 in) — distinguishing it from the smaller true ramshorn (Planorbarius). Unlike many ornamental snails it has a voracious appetite for aquatic plants and should not be kept in planted aquariums; it is best suited to fish-only or utilitarian setups where its algae and detritus grazing is beneficial. It reproduces readily in freshwater.

Size2"
Min Tank10g
peaceful
Zoneall

Care Guide

Diet

Giant Ramshorn Snails are omnivorous grazers that consume algae, detritus, and decaying plant matter as their primary food source. Supplement with sinking pellets or blanched vegetables (zucchini, spinach) 2-3 times weekly. Avoid keeping them in planted tanks, as they will voraciously consume live aquatic plants and can quickly devastate vegetation.

Behavior

These snails are nocturnal and spend daylight hours hidden, becoming active during evening and night hours. They are peaceful toward all fish and other animals, moving slowly across surfaces while grazing. Giant Ramshorns are prolific breeders in freshwater and can quickly overpopulate a tank if food is abundant.

Breeding

Giant Ramshorns breed readily in freshwater aquariums without special conditions, making them prolific reproducers. Females lay clusters of clear, gelatinous egg masses on hard surfaces (glass, rocks, driftwood), with eggs hatching in 7-10 days. Population control is essential; remove egg masses regularly or maintain predatory tank mates to prevent overpopulation.

Common Diseases

Shell Erosion

Symptoms

Pitting, thinning, or dissolving shell surface; white spots or chalky appearance

Treatment

Increase water hardness (8-18 dGH) with calcium supplements or crushed coral; ensure adequate pH (7.0-8.0) and perform regular water changes

Parasitic Infections

Symptoms

Lethargy, withdrawn behavior, reduced feeding, visible parasites on body or shell

Treatment

Quarantine affected snails; perform 25-50% water changes; avoid copper-based treatments (toxic to snails); treat with salt baths (1 tablespoon per gallon for 10-15 minutes) if severe

Bacterial Shell Disease

Symptoms

Discolored patches on shell, soft or mushy areas, foul odor

Treatment

Improve water quality with frequent partial water changes; remove decaying food and waste; maintain stable parameters; isolate severely affected individuals

Starvation/Malnutrition

Symptoms

Slow growth, thin body, reduced activity, shell deformities

Treatment

Ensure adequate algae growth or supplement with sinking pellets and blanched vegetables; maintain stable water conditions and proper tank maintenance

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Quick Facts

diet
Omnivore – aquatic plants (caution!), algae, detritus, sinking pellets
breeding
Prolific in freshwater; egg masses on hard surfaces
lifespan
3–5 years
max size
5 cm (2 in)
tank size
15 gallons minimum
temperament
Peaceful toward fish; destructive toward plants

Water it likes

ph
7.0–8.0
ammonia
0 ppm
nitrate
<20 ppm
hardness
8–18 dGH
temperature
68–82°F (20–28°C)

Stats

Community tips0
Kept by0 hobbyists