Colombian ramshorn
Marisa cornuarietis
A large striped ramshorn from South America that grows to about 2 inches and eats almost every plant, plus other snails' eggs.
Key facts
- Body length
- 1.8 in without fins
- Minimum tank
- 13 gallons
- Group
- Alone is fine
- Temperament
- Peaceful
- Care level
- 1 / 5
- Lifespan
- Not well documented
- Diet
- Vegetables, algae wafers, plants
- Origin
- Northern South America and Central America
- Hardier than53%
- Bigger than24%
- Calmer than68%
Water: their range vs yours
Colombian ramshorn tank mates
- Neon tetraGets along in shared water.Good mates
- Harlequin rasboraGets along in shared water.Good mates
- Fancy guppyGets along in shared water.Good mates
- Panda corydorasGets along in shared water.Good mates
- Cherry shrimpGets along in shared water.Good mates
- BettaGets along in shared water.Good mates
- AngelfishGets along in shared water.Good mates
- Amano shrimpGets along in shared water.Good mates
- Black neon tetraGets along in shared water.Good mates
- Black widow tetraGets along in shared water.Good mates
- Blue dolphin cichlidGets along in shared water.Good mates
- Bristlenose plecoGets along in shared water.Good mates
- OtocinclusColombian ramshorn outcompetes the slow-eating Otocinclus for food; target-feed to make sure it eats.Risky
- Tiger barbTiger barb nips fins; Colombian ramshorn is vulnerable (slow swimmer). Risk is reduced: the group is at least the recommended size.Risky
- Blood parrot cichlidColombian ramshorn outcompetes the slow-eating Blood parrot cichlid for food; target-feed to make sure it eats.Risky
- Convict cichlidConvict cichlid (aggressive) will bully the peaceful Colombian ramshorn.Risky
- DemasoniDemasoni (aggressive) will bully the peaceful Colombian ramshorn.Risky
- DiscusColombian ramshorn outcompetes the slow-eating Discus for food; target-feed to make sure it eats.Risky
- Red swamp crayfishRed swamp crayfish eats snails: Colombian ramshorn.Avoid
- Figure eight pufferFigure eight puffer eats snails: Colombian ramshorn.Avoid
- Green spotted pufferGreen spotted puffer eats snails: Colombian ramshorn.Avoid
- Pea pufferPea puffer nips fins; Colombian ramshorn is vulnerable (slow swimmer).Avoid
How we check
The numbers the tank model uses for Colombian ramshorns: water as ideal and tolerated ranges, bioload from adult mass, space, flow and how they act on other species.
- Standard length
- 4.5 cm (shell)
- Adult mass
- 0.55 g
- Bioload at 25 °C
- 0.96 BU
- Min. water
- 40 L net
- Group
- 1+ (best 2)
- Swims in
- bottom
- Flow
- low
- Body / fins
- invertebrate, normal fins
- Diet type
- omnivore plant
- Fin nipper
- none
- Sensitive to
- copper
Sources: Wikipedia: Marisa cornuarietis · Wikipedia: List of invasive alien species of Union concern
Care notes
Colombian ramshorns come from northern South America and Central America. Sexes are separate, and they lay disc-shaped clutches under water.
They are not for planted tanks, as they damage most plants and even eat the roots of water hyacinth. Since 2025 the species is on the EU invasive species list, so keeping it there is banned.
Questions
What size tank does a colombian ramshorn need?
At least 13 gallons (40 litres of water after decor). Adults reach about 1.8 inches without fins.
How many Colombian ramshorns should be kept together?
One is fine. They do not need company of their own kind.
What water do Colombian ramshorns need?
70–81 °F, pH 7–8 and 0–0 dGH. Colombian ramshorns come from Northern South America and Central America.
How long do Colombian ramshorns live?
Not well documented with good care.
What fish can live with Colombian ramshorns?
Good tank mates include Neon tetra, Harlequin rasbora, Fancy guppy, Panda corydoras and Cherry shrimp. Each is checked both ways for size, fin nipping, temperament, territory and shared water.