Mini River Nerite (Theodoxus fluviatilis)
Mini River Nerite is a snail species belonging to the Neritidae family. It widely lives all across Europe and West Asia. It (Theodoxus fluviatilis) is further classified into two subspecies based on variation in its size, color, and habitat. The brackish water species (Theodoxus fluviatilis littoralis) grows up to 9 mm and is usually black. The freshwater species (Theodoxus fluviatilis fluviatilis) is yellow or white and tends to have a larger size. However, many other coloration patterns are possible.
Theodoxus fluviatilis lives up to two years in an aquarium; although, it can live up to three years in the wild. In nature, this snail lives in rivers, large lakes, brackish coastal waters, and springs. It eats diatoms, algae, and detritus, but due to its small size, it is not as efficient as other algae eaters like Amano shrimp (Caridina multidentata) or Zebra Nerite snails (Neritina natalensis). It can do well both in freshwater aquariums and lightly brackish water aquariums. The European perch (Perca fluviatilis), Spiny-cheek crayfish (Orconectes limosus), and European crayfish (Astacus Astacus) eat these snails; hence they should not be kept in the same tank.
pH: 7,0 – 8,9
Hardness: 5-8 dGH
River Nerite Snail lives in a fairly wide range of temperatures in its natural habitat. However, temperatures above 30° C are harmful to this species. The shell corrodes when pH is below 7.0, so alkaline water (pH 7.0-8.9) is best for this snail. The two subspecies of River Nerite can tolerate different concentrations of dissolved salts. The freshwater species can only tolerate up to 1.5% concentration of salt water, while the brackish water species can survive in up to 18% concentration of saltwater.
Theodoxus fluviatilis snails consume algae by scraping them off the surface of stones, glass, or plants. While they eat mostly all kinds of algae, diatoms are the ideal food for these snails. Other algae-like blue-green algae (cyanobacteria) or green algae (algae that contain cellulose) serve as second-grade food and consuming them in the long term can be harmful to the snails. They also eat detritus, i.e. dead or decaying plant, and animal material. If the tank doesn’t have sufficient algae, exposing it to direct sunlight helps increase the algae growth. Alternatively, algae can be cultured on rocks or plants in a separate tank exposed to direct sunlight and then moved into the tank.
In the presence of sufficient algae, river nerites do not need additional food supplements. Mostly these snails are not accepting commercial foods (fish food or shrimp food) or boiled vegetables. In case there is no food source for them to feed on, dry catappa leaves, mulberry leaves and other types of leaves are also safe for shrimps can be used to support them temporarily. It can feed on the biofilm which will grow on the leaves for some time.
Unlike other nerite snail species, breeding of River Nerites is fairly easy. They breed readily in both fresh water and brackish water. Each snail only breeds once in its lifetime. The water must be slightly warmer (up to 30° C) for breeding. However, keeping them in warm temperatures for extended periods can kill them. They usually breed between April and October. The female River Nerites lay egg capsules each containing 50 to 200 eggs. Sometimes the egg capsules are laid on the mother’s shell or the shells of other snails. Only one snail hatches after about 100 days from each capsule. The rest of the eggs serve as food for the newborn snail. Young River Nerites are born as miniature versions of adult snails and can attain sexual maturity after 18 months.
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