Neritina natalensis

Neritina natalensis in the aquarium

Neritina natalensis [Note 1] is a living in fresh and brackish water snail from the family of Kahn snails ( Neritidae ), which belongs to the order of Neritomorpha. It is common in East Africa. Under the name Zebra Rennschnecke it is popular with aquarists.

Features

Rather the spherical housing of Neritina natalensis, is 20 to 23 mm high in adult worms and reached a diameter of 19-23 mm, having a moderate growth lines. The thread protrudes, is curved and its tip usually been up to. The seam is pressed something wrong and goes down. The case mouth is a little crooked and takes two-thirds to three-quarters of the total length a. The lower muscle strip is well marked and half-hidden in the front view. The outer edge is slightly curved S-shaped top and bottom preferred arcuate. The Columellarfläche is slightly arched, milk-white, moderately wide rather sharply circumscribed and. The Columellarrand has a slight indentation that is bounded above and below by a rather sharp teeth in the center. 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 oblique, fairly broad black stripes, the obliquely downward and forward, sometimes also run in a zigzag form and on a more or less large part of the surface of a network of rather large round mesh. In the upper half of the body intercourse the welts are largely separated from each other, while there is mainly a network in the lower part, but this can also take up almost the whole surface. Forward for housing muzzle the welts are often sparse, so that larger areas and routes remain monochrome yellow. At the intersection, there is no black tie.

The operculum is externally blackish, slightly recessed at the core and at the hem blood red. The inner rim has a slight advantage. The inside flesh is reddish light yellowish gray with a broad beam and the hem out. The pin is red, very wrong and dull. The fin is orange and laterally strongly compressed.

Geographical distribution and habitat

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

The snails inhabit mangrove swamps along the coast.

Way of life

Neritina natalensis is like all snails Kahn dioecious. The male has to transfer the sperm a penis, fertilization takes place in the body of the female. This fixed to stones and roots egg capsules, which can contain up to 100 eggs having a diameter of about 100 microns, respectively. After laying their eggs hatch from the egg capsules deposited first free-swimming veliger larvae, which feed on zooplankton in the ocean than plankton. The worm can not reproduce in fresh water, so die in the freshwater aquarium hatching larvae after a short time. Search on the veliger larvae brackish water areas just before metamorphosis. After metamorphosis, the finished worm migrate back into freshwater areas up or low salinity. The development of the screw is therefore tied to the coastal area.

The worm feeds on algae on aquatic plants and rocks.

Use

Neritina natalensis is popular in the aquarium hobby due to their colorful housing and is used to indemnify the aquariums and aquatic plants from algae. A similar use find a number of similar Kahn snails, which are due to their housing drawing also called zebra racing snails. In aquariums, enclosures reach a diameter of 2.5 cm. The lowest temperature of the aquarium is from 22 to 26 ° C. The screws have a tendency to leave the aquarium, because they can also spend some time on the air to survive. An attitude alone in fresh water and not in brackish water does not meet the natural living conditions of the screw. As with other Kahn snails and even the most snails with free-swimming veliger larvae breeding has not been successful, given the proper diet of living in salt water larvae fails. All zebra racing snails in aquariums are so wild catches.