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Freshwater Molluscan Shells / African unionaceans
Africa has species from several unionacean families, including four European species (Margaritifera auricularia, Psilunio littoralis, Anodonta cygnaea, and A. anatina) in small areas of northern Africa. Pan-African species diversity is reflected in the following table for unionacean mollusca in northern Africa, the Congo basin, and southern Africa.
Genus northern Africa
Van Damme, 1984)
species ;
additional subspeciesCongo basin
(Pilsbry and Bequaert,
1927) species ;
additional subspeciessouthern Africa
(Appleton, 1996)
species ;
additional subspeciesUnio 1 ; 2 1 Parreysia 9 Grandidiera 11 ; 4 Caelatura 2 19 2 Pseudarcula 1 Psilunio 1 Anodonta 2 Aspatheria 3 19 ; 3 1 Spathiopsis 3 ; 3 31 ; 9 2 Mutela 3 29 ; 11 1 Iridina 12 ; 1 Pseudospatha 3 ; 1 Etheria 1 1 1 Totals 16 ; 5 135 ; 29 8 The species counts are imprecise. All three authors was aware that some earlier workers tended to be "splitters"--naming new species for every population encountered. Several species existed in more than one region; for example, all three authors identified Etheria elliptica in the regions they covered. On the other hand, species living in isolated or inaccessible habitats can be overlooked, and although Pilsbry and Bequaert did cover areas outside the Congo basin, it is likely some river systems were not included.
Family Mutelidae
This family is present only in Africa, but is probably related to the South American Mycetopodidae (Banarescu, 1990). Genera include the following;
Mutela
Iridina
Aspatharia
Spathopsis and
Pseudospatha
Unknown Spathopsis species, West Africa. Hinge teeth are lacking in these bivalves.
Mutela hargeri hargeri (E. A. Smith, 1908) African lakes.
Iridina (Cameronia) spekei
(S. Woodward, 1858), and
hinge teeth; LakeTanganyika.
The black and white images below are from Pilsbry and Bequaert, (1927), courtesy American Museum of Natural History.
Pseudospatha tanganyicensis
(E. A. Smith, 1880)
Mutela dubia (Gmelin, 1757)
Mutela (chelidinopsis) hirundo
(E. v. Martens, 1881)
family Unionidae
Genera of the family Unionidae present in Africa include
Unio
Psilunio
Anodonta, including species anatina and cygnaea, and
Caelatura.
Pilsbry and Bequaert (1927) provisionally included
Parreysia and
Grandidiera.
Caelatura aegyptiaca Cailliaud, (1827), Ouagadougou, Africa. x3.
Grandidieria burtoni (Woodward, 1859)
Lake Tanganyika
Parreysia bakeri
(H. Adams, 1866)
Lake Albert
Etheriidae "River oysters" live attached to rocks in deep and rapidly moving water. One variable African species.
Etheria eliptica Lamark, 1807 form tubifera. Throughout Congo
Basin, but only in rapids. Widely used by native peoples for food, and
as a source of lime by early Belgian settlers (Pilsbry and Bequaert, 1927).
Extremely variable in shape and ornamentation.
Other African freshwater bivalves
family Donacidae
Images from Pilsbry and Bequaert, (1927) courtesy American Museum of Natural History.
Iphigenia rostrata Roemer,
1869. 60 mm.
Egeria tenuicula langi
Pilsbry and Bequaert,
1927. 45 mm
Egeria Congica
(Boettger, 1818) Large
heavy triangular clams may
grow to over 120 mm in size.
Synonym Galatea.
World Unionaceans
[Africa] [Asia] [Australia] [Europe] [South America]
