Paleobiogeography and taxonomy of the genus Concholepas (Lamarck, 1801): a review and new evidences
The muricid gastropod Concholepas concholepas, known in Chile as 'loco', is an important component of intertidal and shallow subtidal communities, and is one of the main invertebrates targeted by small-scale fishers (divers) in Chile. Because of its ecological importance and economical value, numerous studies have been conducted to describe its life history, ecology and to understand population dynamics, fishery and management. However, little effort has been done to address the causal factor (s) behind its current geographic distribution and moreover little is known about the past distribution of the different species in the genus. In this paper, first we review the paleobiogeography, historical relationships, taxonomy and geographical distribution of Concholepas species, so to contribute in the reconstruction on the past history of the genus. Second, we discuss the robustness of using shell traits when classifying specimens of the genus Concholepas. Third, we evaluate the taxonomic status of C. concholepas including samples from Peru, the continental coast of Chile and Juan Fernández Archipelago, using a molecular approach. Four main conclusions are reached: (1) the evolutionary history of the genus Concholepas has been characterized by successive phenotypically different forms where the fossils species appear to be distinguishable states in the same evolving lineage; (2) the historical biogeography of Concholepas was probably the result of a southward direction process of expansions and extinctions, with the ancestral species being located in south-central Peru; (3) C. concholepas corresponds to a single taxonomic unit along its continental geographical range of distribution; (4) the mtDNA variation present in C. concholepas does not support the existence of the subspecies C. concholepas fernandizianus in the Juan Fernández Archipelago. We suggest that these results should be considered in future ecological, fishery, management and conservation studies on C. concholepas along the Peruvian and Chilean coast and in the Juan Fernández Archipelago.