Neritina pulligera
| Neritina pulligera | ||||||||||||
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Housing by Neritina pulligera |
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| Scientific name | ||||||||||||
| Neritina pulligera | ||||||||||||
| Linnaeus , 1767 |
Neritina pulligera , also known as steel helmet snail , brown racing snail or black ball racing snail , is a freshwater and brackish water snail belonging to the family of the barn snails (Neritidae), which belongs to the order of the Neritomorpha . It is common on the coasts of the Indo-Pacific .
features
The elliptically shaped, only moderately curved shell of Neritina pulligera reaches a diameter of 21 to 40 mm in adult snails. The thread is very small, sunk and surrounded by the wall-like raised edge of the seam around the body. The transversely oval case mouth is up to 31 mm high and is not provided with a bar. The outer edge is evenly curved, the upper edge along the columellar surface, from which it is separated by a groove, runs slightly S-shaped and at the end merges into an upward and backward curved eye that closes the wall-like girdle of the thread. The columellar border has a slight indentation in the middle, which is provided with about 15 fine blunt teeth. The columellar surface is somewhat rough, flat towards the front and swollen towards the back, delimited from the outside of the shell by a sharp edge at the bottom, and only by color and gloss in the upper two fifths.
The surface of the case has only an indistinct drawing, mostly fine black lines parallel to the muzzle or lighter drops with a black tip pointing forward, which is covered by the dark green-brown or blackish shell skin . The inside of the case mouth and the outer edge are gray-white with an orange-colored band behind the outer edge to the auricle and the lower end of the columellar edge, the surface of which is blackish.
The operculum is glossy yellow-green outside and inside, reddish towards the convex edge and outside with unevenly wide brown-black rays and clear fine radial lines. The edge is black and has a light red border. The inner edge has a slight protrusion. The inside is flesh red with a broad gray beam and pale yellow towards the hem. The blunt cone rises obliquely and has a wider base. The rib is cord-shaped, has very weak transverse and longitudinal lines and ends bluntly.
The shield plates of the radula have a fine serration with about 30 teeth, the first peripheral tooth with 15. The thickened part of the middle plate ends at the back in a concave border line.
Geographical distribution and habitat
Neritina pulligera is widespread in the rivers of the coasts of the Indo-Pacific : in South Africa , Kenya , Madagascar , the Seychelles , Andaman , Nicobar , Indonesia , New Guinea , Palau , Guam , the Carolines , Solomon Islands , Taiwan and Okinawa .
The snails live on stones and leaves in fast flowing rivers near the coast.
Way of life
Neritina pulligera , like all barnacles, is segregated. The male mates with the female with his penis . The female attaches egg capsules to stones and roots, from which free-swimming Veliger larvae hatch. These are drifted into seawater, where they feed on plankton as zooplankton . The larvae can only survive for a short time in fresh water. Shortly before the metamorphosis , the Veliger larvae return to brackish water areas. After the metamorphosis, the finished snails migrate up the rivers. The development of the snail is therefore tied to the coastal area.
The snail feeds on detritus and on algae growth on aquatic plants and rocks. It also eats brush algae .
use
Neritina pulligera is popular in the aquarium hobby and, like a number of other barnacles, is used to keep aquariums and aquatic plants free of algae growth. In the aquarium, the housings reach a diameter of 2.5 to 3 cm. The most favorable temperature of the aquarium is 18 to 30 ° C. As with other barge snails and most of the snails with free-swimming Veliger larvae, breeding has not yet been successful because the larvae living in salt water have failed to properly nourish them. All snails in aquariums are caught in the wild .
literature
- Eduard von Martens : The genus Neritina. Systematic Conchylia Cabinet. Nuremberg, 1879. pp. 49ff. No. 20. Neritina pulligera L.
Web links
- Encyclopedia of Life - Neritina pulligera
- C. Appleton, TK Kristensen, CN Lange, A.-S. Stensgaard, D. van Damme (2010): " Neritina pulligera ". IUCN Red List of Threatened Species . 2012.1. International Union for Conservation of Nature .
- Home biotope: racing snails , swimming snails, barnacles or mermaid snails (Neritidae) : Neritina pulligera LINNAEUS 1767
- Crustahunter: Neritina pulligera - steel helmet snail, brown racing snail, black ball racing snail
- Fischhaus Zepkow: Family Neritidae - mermaid snails