Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

Guide to New Zealand's freshwater invertebrates

Trumpet snail ( Thiaridae : Melanoides )

Diagnostic features

Melanoides is an introduced snail commonly kept in tropical aquaria, but it has also been found in geothermally heated streams in the central North Island. Melanoides has an elongated shell with a gradually tapering spire, and an operculum (protective shield) that covers the aperture (shell opening) when the animal withdraws.

Typical habitats

The first report of Melanoides in the wild in New Zealand was from a geothermally heated stream near Taupo in 2001. They are not uncommon in tropical aquaria in New Zealand.


Like most snails they are grazers, scraping biofilms from submerged surfaces.

Indicator value

Melanoides are only likely to be found in the wild in geothermally heated streams. Some Melanoides species are known to be very pollution tolerant overseas. This genus has not been assigned tolerance values in New Zealand.