Giant Ramshorn Snail care guide
Giant Ramshorn Snail (Marisa cornuarietis) — minimum tank 40 L, temperature 20-28 °C, pH 7-8.5.
Compiled by Aquairi from published sources · Published · Updated
Overview
The Giant Ramshorn Snail (Marisa cornuarietis) is a large flat-coiled apple snail from northern South America. The shell is planispiral and may be gold, brown, blue or pink. It is studied for biological control because it competes with vector snails involved in schistosomiasis transmission.
Taxonomy
- Family: Ampullariidae
- Genus: Marisa
- Scientific name: Marisa cornuarietis
- Common synonyms: Colombian Ramshorn, Apple Ramshorn
Habitat
Native to slow rivers, marshes, ponds and irrigation systems of northern South America (Colombia, Venezuela, Brazil) and the Caribbean. The species tolerates a wide range of warm, hard, alkaline freshwater habitats.
Tank requirements
- Minimum tank volume: 40 L (10.6 US gal)
- Adult size: 4-5 cm
- Temperature: 20-28 °C (68-82 °F)
- pH: 7-8.5
- GH: 8-18 °dGH
- KH: 4-12 °dKH
- Lifespan: 2-4 years
Diet
A herbivore that grazes on aquatic vegetation, algae and decaying plant matter. In aquaria it will graze on soft plants including stem plants, Ceratopteris and Limnobium; combine only with hardy or tough-leaved plants such as Anubias and Java Fern.
Compatibility
Peaceful toward fish and shrimp. Compatible community fish such as tetras and rasboras and other hardy companions are appropriate. Avoid soft-leaved planted tanks, loaches and pufferfish.
Breeding
Oviparous, in contrast with the related Pomacea: females lay translucent gelatinous egg masses submerged on plants or hardscape. Reproduction is steady in well-fed tanks.
Giant Ramshorn (Marisa cornuarietis) Breeding Guide
Overview
Marisa cornuarietis is a large flat-coiled apple snail of the family Ampullariidae. It is a gonochoric species, so it has separate sexes rather than being hermaphroditic. It consumes large amounts of plant matter and is not suited to planted aquariums.
Sexing
Because the species has separate sexes, a breeding group must include both a male and a female. As with related apple snails, external sexing is unreliable, so a small group is the practical way to ensure both sexes are present.
Egg-laying / Reproduction
Unlike most apple snails, Marisa cornuarietis lays its eggs below the waterline. The clutches are characteristic disk-shaped gelatinous masses that adhere to plants, glass and other submerged substrates, so no air gap is required for successful reproduction.
Juvenile Care
Juveniles hatch directly into the water and graze on aquatic plants, algae and decaying matter, including dead fish and snails. Given the species' capacity to spread, surplus snails should never be released into natural waters.
Common Challenges
The species feeds heavily on aquatic vegetation and has been used to retard the growth of water hyacinth and to control Biomphalaria snails that vector schistosomiasis. Its appetite for plants and its invasive establishment in Florida mean it can outcompete and damage planted or natural systems.