Neritina natalensis

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Neritina natalensis
Neritina natalensis in the aquarium

Neritina natalensis in the aquarium

Systematics
Superordinate : Neritimorpha
Order : Neritopsida
Superfamily : Neritoidea
Family : Barnacles (Neritidae)
Genre : Neritina
Type : Neritina natalensis
Scientific name
Neritina natalensis
( Reeve , 1845)

Neritina natalensis is a freshwater and brackish water snail belonging to the family of barnacles (Neritidae), which belongs to the order of the Neritomorpha . It is common in East Africa. Itispopularwith aquarists under the name of the zebra snail .

features

The rather spherical shell of Neritina natalensis , which in adult snails becomes 20 to 23 mm high and reaches a diameter of 19 to 23 mm, has massive growth strips. The thread protrudes, is arched and its tip is usually eroded. The seam is slightly pressed and descends crookedly. The case mouth is slightly crooked and takes up two thirds to three quarters of the total length. The lower muscular bar is well defined and half hidden in the front view. The outer edge is slightly S-shaped at the top and curved forward at the bottom. The columellar surface is somewhat arched, milky white, moderately broad and fairly sharply delineated. The edge of the columella has a slight indentation in the middle, which is delimited above and below by a rather sharp tooth. In between there are no or only very weak denticles.

The surface of the housing has a greenish-yellow to yellow-brown shell skin . It is essentially drawn with crooked, rather wide black welts that run obliquely downwards and forwards, sometimes in a zigzag, and form a network of rather large round meshes on a more or less large part of the surface. In the upper half of the area around the body, the welts are mainly separated from each other, while in the lower part there is mainly a network, but this can also take up almost the entire surface. Towards the front of the case towards the mouth, the welts are often sparse, so that larger areas and stretches remain a solid yellow. There is no black band at the seam.

The operculum is blackish on the outside, somewhat deepened at the core and blood red at the edge. The inner edge has a slight protrusion. The inside is flesh red with a broad gray beam and pale yellow towards the hem. The cone is red, very crooked and blunt. The rib is orange in color and heavily compressed on the sides.

Geographical distribution and habitat

Neritina natalensis is distributed in Africa : in Somalia , Kenya , Tanzania , Mozambique and South Africa ( KwaZulu-Natal and south to Port St. Johns in the Eastern Cape ).

The snails colonize mangrove swamps along the coast.

Way of life

Neritina natalensis , like all barnacles, is of separate sex. The male has a penis for the transmission of sperm , fertilization takes place in the body of the female. This attaches egg capsules to stones and roots, each of which can contain up to 100 eggs with a diameter of about 100 µm. After egg-laying, the egg capsules hatch into free-swimming Veliger larvae, which feed on plankton in the ocean as zooplankton . The snails cannot reproduce in fresh water, so hatching larvae die after a short time in the fresh water aquarium. Shortly before metamorphosis , the Veliger larvae seek out brackish water areas. After the metamorphosis, the finished snails migrate back up to areas with fresh water or low salt content. The development of the snail is therefore tied to the coastal area.

The snail feeds on the algae growth on water plants and rocks.

use

Neritina natalensis in the aquarium

Neritina natalensis is popular in the aquarium hobby because of its colorful housing and is used to keep the aquariums and water plants free from algae growth. A number of similar barge snails are used in a similar manner, and because of their shell design, they are also called zebra snails . In the aquarium, the housings reach a diameter of 2.5 cm. The most favorable temperature of the aquarium is 22 to 26 ° C. The snails have a tendency to leave the aquarium because they can survive in the air for some time. Keeping it in fresh water and not in brackish water does not correspond to the natural living conditions of the snail. 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 zebras in aquariums are caught in the wild .

literature

  • Eduard von Martens : The genus Neritina. Systematic Conchylia Cabinet. Nuremberg, 1879. pp. 96f. No. 55. Neritina Natalensis Reeve.

annotation

  1. ↑ Not to be confused with the species Neritina turrita and Vittina coromandeliana , both of which live in Southeast Asia. Hence the scientific name is preferred.

Web links

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