On the identity and origin of Anadara demiri (Bivalvia: Arcidae)

Abstract

Anadara demiri (Piani, 1981) is an alien species in the Mediterranean Sea extending its range from Turkey westernly to the Adriatic Sea, where it is locally abundant. The species was first identified as Arca amygdalum Philippi, 1847 in the 1970s. The locus typicus of A. amygdalum is China. This first identification has never been discussed and the species has been thought to be of Indo-Pacific origin to date. However, in the Indo-Pacific province no Anadara shows any similarity with A. demiri. Morphological and molecular data suggest A. demiri is closely related to Anadara transversa (Say, 1822), a common species of the eastern coasts of North America. Anadara demiri is hence considered a junior synonym of A. transversa and the origin of this immigration has to be searched in the southern range of this species, maybe the Gulf of Mexico coasts of Florida.