Nerite Snail Zebra (Neritina natalensis)

Neritina natalensis — commonly sold as the Zebra Nerite or Tiger Nerite Snail — is native to fresh and brackish coastal waters across East Africa, from the coastal rivers of Kenya and Tanzania south to South Africa's Natal coast. Like all Neritidae, it is primarily a freshwater species that requires brackish or saltwater conditions for reproduction — larvae cannot complete development in pure freshwater.

The shell is hard and dome-shaped, typically 2–3 cm in diameter when adult, displaying a variety of patterns depending on the specific variant: the classic 'Zebra' pattern shows alternating black and yellow or orange horizontal stripes; the 'Tiger' variant has more irregular spots and markings; 'Olive' nerites are more uniform olive-green. Shell pattern and coloration vary considerably between individuals even within the same variant.

Zebra Nerites are highly specialized algae grazers, using a radula (rasping tongue) to scrape algae, biofilm, and diatoms from hard surfaces including glass, rocks, driftwood, and plant leaves. They are particularly effective at controlling green spot algae, brown algae (diatoms), and biofilm — types of algae that are difficult to remove by other means.

Their most valuable attribute for the aquarist is the inability to reproduce in freshwater: females may deposit small white egg capsules on surfaces (including plant leaves and glass), but these eggs will not hatch without brackish water, preventing the population explosions that occur with pest snails like Malaysian Trumpet Snails.

Zebra Nerite Snails are adaptable and undemanding: pH 7.0–8.5, hardness 8–18 dGH, and temperatures 22–28°C. They prefer harder, alkaline water — soft, acidic water etches and damages their shells over time, causing pitting. Calcium-rich water is beneficial for maintaining shell integrity.

Suitable for aquariums of all sizes from nano setups to large community tanks. They require hard surfaces for grazing — glass, rocks, driftwood, and smooth decor provide ideal grazing habitat. Ensure the aquarium has sufficient algae growth, biofilm, and supplemental feeding if algae is insufficient.

Supplement their diet with algae wafers and blanched vegetables (zucchini, spinach, cucumber) when natural algae growth is insufficient to sustain them. They graze continuously and require a consistent food source.

Zebra Nerites are safe with all fish, shrimp, and peaceful invertebrates. They are susceptible to aggressive loaches (Clown Loaches eat snails) and some cichlids that may attempt to crack their shells. Assassin snails (Clea helena) will consume Nerites — avoid housing together.

Stocking rate: 1 snail per 5–10 liters is typical for algae control purposes. They do not reproduce in freshwater, so population management is not a concern. Occasionally escape the tank — ensure a secure lid and wipe down any that venture above the waterline.