ABSTRACT
The northeast Atlantic region has been the focus of intense phylogeographic research over the last 20 years. However, most of those studies have been centered on the Atlantic-Mediterranean junction and have consistently neglected the Macaronesian archipelagos (Cape Verde, Madeira, Selvagens, Azores, and Canary Islands). Here we used mtDNA cytochrome c oxidase subunit I (COI) sequences to infer common patterns of differentiation in three achelate lobster species (Decapoda: Palinura: Achelata): Scyllarides latus (N = 26) from the Cape Verde Islands, Azores, and Atlantic coast; Palinurus elephas (N = 247) from the Azores, Atlantic, and Mediterranean; and Panulirus regius (N = 19) from the Cape Verde and southwestern Africa. Two competing phylogeographic hypotheses were tested: panmixia due to long-distance dispersion and population structuring due to environmental factors (e.g., oceanographic barriers and currents). Our analyses suggest: 1) panmixia in the Azores populations and between the Azores and the continental populations of P. elephas and S. latus; and 2) weak genetic differences, in relation to oceanographic fronts, between the Atlantic and Mediterranean populations of P. elephas and a trend for differentiation, in relation to marine currents, between Cape Verde and southwestern African populations of P. regius.
