Minimum Tank Size: 10 gallons (37 liters)
Care Level: Easy
Water Conditions: PH 7.0-8.5 and Moderately Hard to Very Hard
Temperature: 71-79 °F (22-26 °C)
Maximum Size: 1 inch (2.5 centimeters)
Nerite snails (Neritina natalensis), also known as tiger snails, or zebra nerites, is a small freshwater snail that is prized for its algae eating ability. While it is a freshwater snail, it only breeds in brackish waters, so it has the added benefit of not overrunning an aquarium with larvae.
These snails are native to East Africa and can be found in the North at the mouth of the Jubba River in Somalia, while in the east it is found in the mangrove swamps and lagoons of Kenya and Tanzania. In the south, it is found in the coastal lowlands of Mozambique and South Africa. In fact, the name natalensis actually refers to Natal: an old province of South Africa (now known as KwaZulu-Natal).
While most publications state nerite snails have a relatively short lifespan of 2-3 years, there is a significant amount of anecdotal evidence they can live far longer. It’s not unusual for people to keep these snails for 4-5 years, and some aquarists claim they can live up to a decade. But with that being said, a lifespan of 2-3 years seems to be pretty average for these snails.
They also remain a manageable size for aquariums, and a full-grown nerite snail is about 1 inch in diameter (2.54 cm). Their small size, inability to reproduce in freshwater, and voracious appetite for algae, makes them among the best algae eaters available in the hobby.
Nerite snails are small and hardy enough that they can survive in nearly any size aquarium – assuming all their needs are met. But since they are rarely kept on their own, it’s best to focus on the aquarium size requirements of their tankmates. However, on the off chance a person is keeping these snails in a species-only tank, then a 10 gallon (37 liter) aquarium would be more than adequate.
These snails are incredibly docile and won’t bother any other inhabitants of an aquarium. However, fish aren’t always peaceful towards these snails and any snail eating fish should be avoided. This includes most loaches (botia), puffer fish, and any large, aggressive cichlids. Also, many fish like gouramis and bettas will attempt to attack snails, but usually won’t be able to kill them – though they often injure them.
Something to be wary of with nerite snails, is that they like to wander out of the water in their aquarium. Many will climb out of the water and fall off the lip of their tank. The fall often damages their shell, and if they aren’t found quickly to place them back in water, they will die of desiccation.
Nerite snails are often purchased for their algae eating abilities, but their diet should still be supplemented with other foods to keep them in peak health. The best food to feed them is a vegetarian sinking pellet and I strongly recommend Hikari Tropical Algae Wafers.
Their diet can also be supplemented with blanched vegetables, and they will appreciate zucchini medallions, cucumber, broccoli, and lettuce. Make sure to remove any uneaten food within 24 hours, before it starts to decay and foul the water.
Unlike many other snails, nerites aren’t hermaphroditic. They are either male or female, but are very difficult to sex. However, one easy way to sex them is to observe their breeding: The male is usually on top during mating. If that fails, the only other reliable way to sex them is to simply watch which of them is laying eggs.
Depending on your point of view, one downside to nerite snails, is that they don’t reproduce in freshwater. Breeding snails is often one of the most exciting aspects of keeping them, but with nerite snails, it’s very difficult to breed them and raise their larvae.
But if someone is interested in trying to breed these snails and wants a challenge, then they should start with setting up a brackish water tank. These fish will not breed in a freshwater or marine tank. Once the brackish water aquarium has been setup, a minimum of six nerite snails should be added. By adding six snails, it’s a virtual certainty there will be at least one male and female.
A calcium rich substrate can be used (such as crushed coral), but it‘s not required if the water is hard enough. Also, the water temperature should be kept above 75°F (24°C), which should help to encourage breeding. Though to be honest, these snails rarely need encouragement and will often lay eggs even in freshwater, room temperature tanks, where they can’t possibly hatch.
Once the eggs have been laid, the baby snails should be moved to a marine tank. It’s very important that this tank have at least one good source of algae in it. After they have spent a few weeks growing – and it must be at least four weeks – they can then be moved back to a freshwater tank.