Distribution patterns of gastropods and bivalves at the Yucatan peninsula, Mexico

Abstract

Records of 298 molluscs species (99 bivalves and 199 gastropods) from 33 localities along the shoreline and the corals reef of the Yucatán peninsula, were analized in terms of their geographic range of the information content and species richness. Coral reef areas showed to have the highest species richness. The families with the highest species numbers were Tellinidae, Arcidae, Mytilidae and Lucinidae for lamellibranchs, whilst the families Fissurellidae and Muricidae showed the highest species richness among the gastropods. Four areas were defined according to the distribution patterns of the species found: west coast, north coast, east coast and coral reef areas. The most distinctly defined area was the east coast, mostly due to its gastropod fauna. Finally, 16 geographic distribution patterns were found, from which the one whose elements range from the Caribbean Province to the Brazilian Province hold the highest species richness, whilst the elements of the Caribbean Province comprise the highest number of endemisms.