Clithon spinosum

Clithon spinosum is a species of brackish water and freshwater snail with an operculum, a nerite. It is an aquatic gastropod mollusk in the family Neritidae, the nerites.

Distribution
Distribution of Clithon spinosum includes the Indo-Pacific and it ranges from New Guinea and south-eastern Asia and eastern Asia to Marquesas. It also occurs in Japan, New Georgia, Fiji and Tahiti and in French Polynesia including the following Society Islands: Tahiti, Mo'orea, Raiatea, Huahine.

Description
There are always spines on its shell. Spines are long and thin and they are directed rearward. The width of the shell is 15–20 mm.

Ecology
Clithon spinosum is a dioecious (it has two separate sexes) and amphidromous snail. Adults live in freshwater and larvae are marine. Larvae are long-lived planktotrophs. Adults prefer boulders and cobbles over granules as a substrate. They were found mainly on bottom of rocks in aquaria and in situ. They are reported from altitude 0–10 m a.s.l. They can reach densities up to 57.0 ± 17.3 snails per square meter of a stream. Adults can survive 8 hours in seawater (longer exposure was not tested).

It is not used as food source by humans.