2 kinds · tap one for a closer look
Peaceful but a heavy plant eater.
142 species in our list are a good match.
Peaceful but a heavy plant eater.
Check your local laws. EU: on the list of invasive alien species of Union concern since 7 Aug 2025 (Implementing Reg. (EU) 2025/1422 under Reg. 1143/2014), so keeping, breeding, selling and importing it are restricted EU-wide. US (federal): USDA APHIS says live snails of the family Ampullariidae (except Pomacea diffusa) may not be imported or moved between states except into an APHIS-inspected research containment facility. Check the rules where you live before you buy one, and never release it into the wild.
Good to know: Restricted in some places as an invasive species.
Algae, vegetables and fish food.
Tap a food to see what it is.
Separate sexes, but males and females cannot reliably be told apart by eye.
Common problems. Tap one to see the signs. This is a guide, not a diagnosis.
Egg-laying · Easy
Lays transparent jelly egg clutches below the waterline on plants and glass (unlike Pomacea, which lays above water); females store sperm for months.
Any two.
Any tank.
Warm water and food.
Jelly clutches of up to about 80 eggs that hatch in up to about 20 days depending on temperature; a female may lay about 1,700 eggs a year.
Young snails graze.
A large flat-shelled apple snail from northern South America and Central America that eats plants, algae, other snails' eggs and carrion; invasive in Florida, Texas, the Caribbean and parts of Europe, and listed as an invasive alien species of EU concern since 2025.
Linnaeus described this apple snail in 1758. It has been introduced to some tropical regions to control the snails that carry schistosomiasis, and it is kept as an aquarium snail.
First described by Carl Linnaeus in 1758. Named for 'Cornuarietis' means ram's horn.
17 facts checked with sources
Sold as "giant/Colombian ramshorn" but it is an apple snail (Ampullariidae), not a true ramshorn (Planorbidae).
MolluscaBase (via WoRMS): Marisa cornuarietis (Linnaeus, 1758), AphiaID 737469Legacy has no family.
MolluscaBase (via WoRMS): Marisa cornuarietis (Linnaeus, 1758), AphiaID 737469 · The Shrimp Farm (hobby care reference, 2022): Giant Ramshorn Snail CareShell diameter (planispiral shell): 35-56 mm; legacy 5 cm fits. Applesnail.net prints "18-22 mm wide, 48-56 mm high", apparently with width and height swapped relative to Barker (2019) as quoted in the EU risk assessment.
EU risk assessment of Marisa cornuarietis under Reg. (EU) 1143/2014 (completed 2021, revised 2022; hosted by ISPRA) · Wikipedia: Marisa cornuarietis (cites IUCN 2011, Rawlings et al. 2007, USGS NAS) · The Shrimp Farm (hobby care reference, 2022): Giant Ramshorn Snail CareThrives 18-30 °C, ideal 20-26 °C; The Shrimp Farm 71-84 °F = 22-29 °C. Legacy 20-28 lies within.
EU risk assessment of Marisa cornuarietis under Reg. (EU) 1143/2014 (completed 2021, revised 2022; hosted by ISPRA) · The Shrimp Farm (hobby care reference, 2022): Giant Ramshorn Snail Care · Applesnail.net (Stijn Ghesquiere; long-running apple snail reference): Marisa cornuarietisOnly a hobby figure (7.5-8.0); applesnail.net (family level) says pH 7 or higher. Legacy 7-8.5 is broader but compatible.
The Shrimp Farm (hobby care reference, 2022): Giant Ramshorn Snail Care · Applesnail.net: general apple snail care guide (genus/family-level, not species-specific)Qualitative only: avoid soft water.
The Shrimp Farm (hobby care reference, 2022): Giant Ramshorn Snail Care10 US gal x 3.785 = 37.9 L; legacy 40 L agrees after rounding.
The Shrimp Farm (hobby care reference, 2022): Giant Ramshorn Snail CareHobby source only; legacy 2-3 years agrees.
The Shrimp Farm (hobby care reference, 2022): Giant Ramshorn Snail CareHarmless to fish and shrimp but eats other snails' eggs, small snails and plants; "peaceful" not a good fit, left unknown.
The Shrimp Farm (hobby care reference, 2022): Giant Ramshorn Snail Care · Applesnail.net (Stijn Ghesquiere; long-running apple snail reference): Marisa cornuarietisWild habitat note only; legacy says bottom.
Applesnail.net (Stijn Ghesquiere; long-running apple snail reference): Marisa cornuarietisLegacy has no range. Applesnail.net also lists Honduras.
Wikipedia: Marisa cornuarietis (cites IUCN 2011, Rawlings et al. 2007, USGS NAS) · Applesnail.net (Stijn Ghesquiere; long-running apple snail reference): Marisa cornuarietis · EU risk assessment of Marisa cornuarietis under Reg. (EU) 1143/2014 (completed 2021, revised 2022; hosted by ISPRA)Family-level statement on sexing (applesnail.net); legacy "not visibly different" agrees.
Wikipedia: Marisa cornuarietis (cites IUCN 2011, Rawlings et al. 2007, USGS NAS) · Applesnail.net: general apple snail care guide (genus/family-level, not species-specific)Legacy 20-100 per clutch; the only per-clutch figure found is "up to 80" (hobby source).
The Shrimp Farm (hobby care reference, 2022): Giant Ramshorn Snail Care · EU risk assessment of Marisa cornuarietis under Reg. (EU) 1143/2014 (completed 2021, revised 2022; hosted by ISPRA)Legacy says "South American"; range also includes southern Central America.
Applesnail.net (Stijn Ghesquiere; long-running apple snail reference): Marisa cornuarietis · EU risk assessment of Marisa cornuarietis under Reg. (EU) 1143/2014 (completed 2021, revised 2022; hosted by ISPRA) · Wikipedia: List of invasive alien species of Union concern (cites Reg. (EU) 2025/1422)EU-Lex quote is from a fetch-tool reading of the official PDF (the Annex row). The Regulation 1143/2014 transitional rules for existing pets were not checked. APHIS names Ampullariidae as a family (P. canaliculata as example) under PPQ 526 plant-pest permits; individual US state rules not checked. Legacy mentioned only state restrictions.
Commission Implementing Regulation (EU) 2025/1422 of 17 July 2025 updating the list of invasive alien species of Union concern (Reg. 1143/2014) · Austrian Federal Office for Food Safety (BAES): Further update of the list of invasive alien species (2025) · Wikipedia: List of invasive alien species of Union concern (cites Reg. (EU) 2025/1422) · USDA APHIS: Snails and Slugs (PPQ 526 plant pest permits; page last modified 31 Aug 2026)