Family of Thiaridae (Melaniidae)
Origin: all tropical regions
Recent distribution: a very wide diversity of aquatic environments, except marshes with papyrus and biotops that dry-out regularly. Tolerates a moderate salinity (Brown, 1980)
Description: The only freshwater snail in the shape of a
tower, that appeared in Northern Africa, with a spiral shaped shell.
Only one species lives in the Sahara, the
cosmopolitan M. tuberculata. It reproduces by parthenogenesis
and was distributed worlwide by birds and men. The most ancient of this afrotypical
genus and of the African species dates from the lower-Miocene (Mohari Fm., Sinda
nale: Melanoïdes tuberculata (Miffler, 1774, Nerita), Genus Melanoides Oliver,
Size: maximum 47 x 14 mm, but generally smaller (2 cm).
Breathing: aquatic, through gills.
Temperature: 22 to 32°C
Utility: eats the food surplus and moves the soil, improving air circulation.
Particularities: nocturnal species, remains in substrate durig daytime. In the opposite of the majority of snails and like Pomacea, there are males and females. with Biomphalaria pfeifferi et Bulinus truncatus, M. tuberculata is the commonest species in the water spots of Sahel and Sahara.
This snail, which is quite useful to the aquarist, is a goo indicator of the aquarium health.
If the aquarist distributes too much food to his fishesn melano´ds will be very happy to eat the latter ... and consider that the biotop is very pleasant and REPRODUCE !!!
The logical consequence of this invasion is that all the melano´ds will come out during nightime and make the aquarium look like a trashbin !. They will in turn produce waste and therefore contribute to the biotop degradation.
The show will be alike if the water becomes poor in oxygen, les melanoïds react like fishes in this case ... MASSIVE MIGRATION TO THE SURFACE !
The aquarist must not think about getting completely rid of these diggers, but he must learn how to manage adequately his aquarium. Observe the behaviour of this snail species may be very useful.
But if the infestation has started, it appears as difficult to stop the hordes of cones. Most of the aquarists will try to catch them by offering some boiled lettuce ... it is no use, their proliferation ratio is much superior to our capacity to catch them and remove them manually.
I recommend the following solutions:
If the substrate is composed of thin sand, the latter can be simply sieved;
If the substrate is composed of medium grain size sand, it will be necessary to introduce predators, such as Botias (never alone, they hate solitude), Tetraodons, macropodes, ...
It is a fact that the reason of the invasion must be taken into account, and it is quite better to introduce small amounts of fish food at several moments of the day rather than accustom them to a "twice a day feeding".
Finally, do not throw the captured melanoïds to the trashbin or in the toilet, they are very useful as natural food for tetraodons or botias; if you don't posses any of these, the shop where you usually buy your products, plants and fishes is bound to receive them happily as they are natural / live / free food for species that need them to survive.