Marisa cornuarietis english


	Aquarienschnecken.de


	Marisa cornuarietis(Linnaeus, 1758)

Trivial names:

giant ramshorn snail

striped ramshorn snail

giant Columbian ramshorn snail


	Description: The thick-walled, 5 to 7 cm large shell of Marisa is flat, the underside is mostly light in color and deeply sunk in (deep navel). The upper side of the striped variant is often of a uniform dark color. It has an operculum, which closes the shell off entirely. Its growth rings are concentric.


	The basic shell color is beige, with 5 to 7 bands whose colors vary between light brown, even reddish, to dark brown. There are also specimens with a uniformly yellow shell. The body shows a striking white, grey and black pattern. Often the upper side is just beige, the underside dark brown. Marisa has a lung and a siphon.

banded shells and color variants of Marisa cornuarietis

On the outside, Marisa can be sexed by the shell form and the operculum. The male has more globose whorls and a rounder operculum than the female.

The male can be seen on the left, with a rounder shell

The female has a more unround shell diameter, this was made clearer by coloring the picture.

Range/Habitat:

In nature, Marisa live in rivers, lakes and swamps; they prefer areas with a dense vegetation. They originate from subtropical to tropical alternate climates. It is found from Brasil over Honduras, Venezuela, Panama to Costa Rica (1952), but also in Florida (1970) and Texas (since 1990). It spreads where the minimum temperatures do not go under 12 °C and where it finds enough food plants and water. Even in brackish water areas with a salinity of up to 3% Marisa can live, though not reproduce.

Water parameters:

Unfortunately, the editor does not have any exact data on this.

Reproduction:

The adult male sits on the female's right side and inseminates it on the inside.

Under water, the female lays its about 10 cm long clutch of 100 to 200 eggs on hard waterplant stems or leaves. Within 3 days the eggs swell to triple their original volume. At a constant water temperature of 26 °C the young snails hatch within 10 days.




	three-day old clutch, eggs are already slightly swollen




		six-day old Marisa clutch, eggs are visibly swollen

Life span:

Unfortunately, the editor does not have any exact data on this.

Food:

Marisa eats all kinds of aquatic plants with the exception of Elodea and Pistia. Moreover, it accepts vegetables, fall leaves, mosquito larvae, shrimp or clam meat, dry food of any composition, and carrion. Young snails sometimes feed on clutches of their own species when they suffer from a lack of proteins or if they are overstocked. Snails without an operculum are also eaten.

Socialization:

Marisa cornuarietis is a robust snail. It can be kept in Malawi tanks as it does very well even though other aquarium inhabitants might be pestering it.

However, it really thrives in invert tanks (without crayfish). If you want to keep one single snail a male would be advantageous, for the hatch rate of one single clutch is 99%, in my experience.

Additional information:

A look at its habitat leads us to optimized keeping. Marisa does well with moderatly moving water, lush plant growth and lots of floating plants. In order for the snail to grow to its full size, a tank with a length of at least 50 to 60 cm is required.

Its high reproductivity makes it a very suitable food snail.

Weblinks:

Aquarienschnecken [ Food thread – in German ]

http://www.applesnail.net/content/species/marisa_cornuarietis.htm [ Informational site about keeping conditions, breeding, shell pictures etc. ]

http://www.rhusmann.de/aqua/marisa.htm [ private page about keeping conditions, breeding, shell pictures, personal experience – in German.

Bio - Uni- Frankfurt

Oehlmann, J., U. Schulte-Oehlmann, J. Bachmann & M. Oetken (2005): Low dose effects of bisphenol A in the freshwater snail Marisa cornuarietis. Environ. Res. 98, 413.

[ PDF in the download section, about a test series with M. Cornuarietis and bisphenolt Bisphenol. ]


		This page was actualized on April 18, 2009 Author: Alexandra Behrendt Translator: Ulrike Bauer

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