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" 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.[2]
Historically, several varieties (excluding the nominal var.) had been identified by Pallary and Bourguignat, including:[3]
† Denotes that the variety is not mentioned by the nomenclator of Neubauer 2016