Descripción
The horned nerite is a nerite in miniature: barely 1 cm, with yellow and black stripes and curved spines projecting from its shell that give it a look no other aquarium snail has.
It shares the zebra nerite's two best qualities — it eats algae efficiently and cannot reproduce in fresh water — but its size makes it far more versatile. In a 20 or 30 litre nano tank, a three-centimetre adult nerite is out of proportion and dominates the scene; a horned nerite fits perfectly and can be kept in a group.
One detail worries many people for no reason: the spines wear down and fall off over time. That is entirely normal and indicates no deficiency or disease. An adult usually has fewer spines than a youngster, or none, and is just as healthy.
What does need watching is the same as across the family: the shell needs hard water to avoid eroding, and with such a small body the margin is even narrower than in the zebra.
It lives with everything, is safe with shrimp and their fry, and does not touch plants. Like its relatives, it escapes above the waterline if there is no lid.
Hábitat
Clithon corona comes from streams and river mouths in Southeast Asia, with the same cycle as other nerites: adults in fresh water, larvae needing brackish.
It needs hard, alkaline water for the same reason as its larger cousin — the shell is calcium carbonate and dissolves in acidic water — but here the matter is more urgent. A one-centimetre shell has far less material to lose before erosion reaches the interior, so in soft water a horned nerite lasts considerably less than a zebra.
It appreciates hard surfaces to graze: glass, rocks, wood and leathery leaves covered in algal film. In a mature planted nano tank it finds plenty of food; in a newly set up, very clean one it runs out of anything to rasp and quietly starves.
That is the commonest mistake with nerites in general: buying them for a new tank before there are any algae. They arrive somewhere spotless and have nothing to eat.