Biomphalaria prona (Gastropoda: Planorbidae): a morphological and biochemical studyTwo samples of Biomphalaria prona (Martens, 1873) from Lake Valencia (type locality) and seven from other Venezuelan localities were studied morphologically (shell and reproductive system) and biochemically (allozyme electrophoresis). In spite of marked differences in shell characters, all of them proved indistinguishable under the anatomic and biochemical criteria. So far B. prona has been considered an endemic species, restricted to Lake Valencia. It is now demonstrated that the extralacustrine populations refered to Biomphalaria havanensis (Pfeiffer, 1839) by several authors correspond in shell characters to an extreme variant of B. prona from the Lake and really belong to the last*mentioned species. They may be regarded as the result of a process of directional selection favoring a shell phenotype other than those making up the modal class in the Lake.
Gastropoda Planorbidae; Biomphalaria prona; Biomphalaria havanensis; morphology; allozymes; Venezuela
Biomphalaria prona (Gastropoda: Planorbidae): a morphological and biochemical study
W. Lobato Paraense
J. P. Pointier1
B. Delay2
A. F. Pernot2
R. N. Incani3
C. Balzan4
P. Chrosciechowski4
École Pratique des Hautes, Centre de Biologie Tropicale, Laboratoire de Biologie Marine et Malacologie, Perpignan, France
Institut des Sciences de l'Évolution, Laboratoire de Génetique et Environnment, Montpellier, France
Universidade de Carabobo, Facultad de Ciencias de la Salud, Departamento de Parasitologia. Laboratorio de Bilharzia, Valencia, Venezuela
División de Parasitosis Intestinales y Esquitosomiasis, Dirección General Sectorial de Malariología y Saneamiento Ambiental, Maracay, Venezuela
Two samples of Biomphalaria prona (Martens, 1873) from Lake Valencia (type locality) and seven from other Venezuelan localities were studied morphologically (shell and reproductive system) and biochemically (allozyme electrophoresis). In spite of marked differences in shell characters, all of them proved indistinguishable under the anatomic and biochemical criteria. So far B. prona has been considered an endemic species, restricted to Lake Valencia. It is now demonstrated that the extralacustrine populations refered to Biomphalaria havanensis (Pfeiffer, 1839) by several authors correspond in shell characters to an extreme variant of B. prona from the Lake and really belong to the last*mentioned species. They may be regarded as the result of a process of directional selection favoring a shell phenotype other than those making up the modal class in the Lake.
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