A study of the malacological fauna was carried out with the purpose of identifying the species of bivalves, in four stations of the Bay of Chame, Province of Panama Oeste. Samplings were carried out monthly for 6 months (July to December 2009), in the sampling stations were from the mangrove area of El Líbano, Punta San Juanito, The Sajalices River Bank and The Black Bass; these were cataloged according to the granulometry of the sediment as muddy, sandy and sandy-muddy; additionally, for the mangrove area in Lebanon, root and mud substrates were considered. The organisms were obtained manually and immediately introduced into previously labeled plastic bags; Later, the bivalves were separated for identification up to the category of species. For the substrates studied (root and mud) in Lebanon, analyses of the Shannon-Wiener diversity indices, Simpson predominance and Equitativity were presented. A total of 961 individuals were collected, grouped into 28 genera belonging to the class Bivalvia; 52 species were identified; the most abundant were: Leukoma asperrima (212), Iliochione subrugosa (85) and Dosinia dunkeri (78), the highest indices of diversity, abundance and homogeneous distribution were obtained in the mud substrate. In addition, El Líbano registered the highest abundance, however, it showed less diversity, compared to the other stations, with The Sajalices River Bank and The Black Bass being the stations with the highest diversity of species, which is related to the environmental characteristics of the area, such as currents and predominance of winds.
