Melanopsis letourneuxi is a species of freshwater gastropod[1] endemic to streams in coastal Morocco and Algeria.

Melanopsis letourneuxi is found almost exclusively in relatively shallow medium-sized streams with stony substrates, rarely occurring in stagnant sources.

The species had historically been reported from several localities in north Africa, including a site in Algeria or (disputedly) Morocco - "in the source and the river Moulouya, west of Maghnia"[1] from which it has not been documented recently- and two confirmed adjacent Moroccan sites -Berguent and Ras el Ain at Aïn Beni Mathar - in which it is exceedingly rare.

Remaining populations are threatened by water abstraction, pollution, and shell-collecting.

had been identified by Pallary and Bourguignat, including:[3] † Denotes that the variety is not mentioned by the nomenclator of Neubauer 2016 *Denotes that the variety is considered invalid by the nomenclator of Neubauer 2016