New records of bentharca asperula (Dall, 1881) (Mollusca, Bivalvia, Arcidae) from Brazil

Abstract

Specimens of Bentharca asperula (Dall, 1881) were obtained from deep waters of the coasts of the Rio de Janeiro and São Paulo States, and their shells described, illustrated and compared with descriptions and illustrations obtained from the literature. This species has a small strongly inequilateral shell, trapezoidal in outline and expanded ventro-posteriorly; their umbos are placed at about 1/3 of the anterior length of their straight hinge line. The external sculpture consists of irregular spaced concentric ridges, intercepted by fine radiating striae; the periostracum is hairy, forming a cover as a thatch. Hinge teeth are small, disposed in two series interrupted by the ligament. With this finding of living specimens from the Bacia de Campos, the distribution of B. asperula can now be extended in the Brazilian coast, confirming its wide spread in the Atlantic Ocean.