Taxonomy of Tropical West African Bivalves V. Noetiidae

Abstract

Five species of Noetiidae are described from tropical West Africa, defined here as between 23° N and 17°S. The Noetiidae are represented by five genera, and four new taxa are introduced : Stenocista n. gen., erected for Area gambiensis Reeve; Sheldonella minutalis n. sp., Striarca lactea scoliosa n. subsp. and Striarca lactea epetrima n. subsp. Striarca lactea shows considerable variation within species. Ecological factors and geographical clines are invoked to explain some of this variation but local genetic isolation could not be excluded. The relationships of the shallow water West African noetiid species are analysed and compared to the faunas of the Mediterranean, Caribbean, Panamic and IndoPacific regions. Stenocista is the only genus endemic to West Africa. A general discussion on the relationships of all the shallow water West African Arcoidea is presented. The level of generic endemism is low and there is clear evidence of circumtropical patterns of similarity between species. The greatest affinity is with the Indo-Pacific but this pattern is not consistent between subfamilies. Notably the Anadarinae have greatest similarity to the Panamic faunal province.