Freshwater Molluscan Shells


The Melanopsidae have a strange disjunct distribution, mostly around the Mediterranean.

Melanopsis is native to Spain, Morocco, and the Middle East,
is found in Central Europe, but their closest relative,

Zemelanopsis, is native to New Zealand and New Caledonia.

Faunus (placed in the family Thiaridae by many authors, and Potamididae by Brandt (1974)) ranges through Southeast Asia, the East Indies, and Madagasgar.

According to Behrendt, the Melanopsidae can feed on detritus or the algae growing on hard surfaces, and many are willing to consume either. Sexes are separarate, and adult females have a small whitish reproductive opening on the right side of the foot. Reproduction occurs several times throughout the multi-year life of the snail. Fertilization may occur by males releasing sperm directly into the environment, as mating behaviour has not been observed. Eggs are usually layed in clutches on hard surfaces such as the underside of stones, but may also be scattered on soft substrates, and hatch into tiny snails without going through a larval stage.

Northern Africa

Melanopsis attenuata
(Pallary, 1920),
Morocco, from two different sources. The
magnified specimen (left) shows no trace of the
color banding seen in the specimens above.
Melanopsis cesari Pallary, 1920.
Morocco. x3.


Melanopsis buccinoidea Olivier, Jordan River   Melanopsis foleyi (Pallary),



Melanopsis magnifica Bourguignat,
with periostracum removed, Morocco.


Melanopsis magnifica ingens Pallary, Morocco.


These specimens were obtained from dealers identified as "Melanopsis praemorsa (Linnaeus, 1758)", the left pair from Crete, Greece, and the right from the Sea of Galilee. Van Damme (1984) also includes within this named species all of the forms from northern Africa, some of which are shown above. This may have been in response to the earlier excesses of Jules Rene Bourguignat, "one of the epigons of Victorian species-makers," Van Damme expressed the opinion that his species splitting, ignoring natural variation, caused permanent damage to African malacology. He goes on to mention that Pallary was "a staunch devotee of Bourguignat."


Esperiana esperi (A. Ferrusac, 1823), Danube River,
  Esperiana daudebartii
(Prevost 1821),

  Unknown Melanopsis sp
Hot spring in Zaragosa, Spain.
Melanopsis bicarinata Spain

Indo-Pacific Faunus species

Faunus ater (Born, 1778), native to Philippines, Southeast Asia, and the East
Indies. Brandt (1974) includes Faunus with the family Potamididae and indicates
that "It lives in fresh as well as slightly brackish water near the coast in creeks,
small rivers and lagoons."
  unknown Faunus species,

New Zealand and Oceania

Zemelanopsis trifasciata Gray, 1843,
North Island of New Zealand, streams.
  Melanopsis frustulum
Morelet, 1856. New Caledonia

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