Phylogeography of a Marine Insular Endemic in the Atlantic Macaronesia: The Azorean Barnacle, Megabalanus azoricus (Pilsbry, 1916).
The Azorean barnacle, Megabalanus azoricus (Pilsbry, 1916), is a Macaronesian endemic whose obscure taxonomy and the unknown relationships among forms inhabiting isolated Northern Atlantic oceanic islands is investigated by means of molecular analysis herein. Mitochondrial data from the 16S rRNA and COX1 genes support its current species status, tropical ancestry, and the taxonomic homogeneity throughout its distribution range. In contrast, at the intraspecific level and based on control region sequences, we detected an overall low level of genetic diversity and three divergent lineages. The haplogroups α and γ were sampled in the Azores, Madeira, Canary, and Cabo Verde archipelagos; whereas haplogroup β was absent from Cabo Verde. Consequently, population analysis suggested a differentiation of the Cabo Verde population with respect to the genetically homogenous northern archipelagos generated by current oceanographic barriers. Furthermore, haplogroup α, β, and γ demographic expansions occurred during the interglacial periods MIS5 (130 Kya - thousands years ago -), MIS3 (60 Kya), and MIS7 (240 Kya), respectively. The evolutionary origin of these lineages is related to its survival in the stable southern refugia and its demographic expansion dynamics are associated with the glacial-interglacial cycles. This phylogeographic pattern suggests the occurrence of genetic discontinuity informative to the delimitation of an informally defined biogeographic entity, Macaronesia, and its generation by processes that delineate genetic diversity of marine taxa in this area.
Molecular Systematics Laboratory, Department of Biochemistry and Molecular Biology, University Santiago de Compostela, A Coruña, Galicia, Spain.
Javier
J
Quinteiro
Departament of Biology, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.
Pablo
P
Manent
Molecular Systematics Laboratory, Department of Biochemistry and Molecular Biology, University Santiago de Compostela, A Coruña, Galicia, Spain.
Lois
L
Pérez-Diéguez
Departament of Biology, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.
José A
JA
González
Departament of Enginery and Sea Sciences. University of Cabo Verde, Mindelo, São Vicente, Cabo Verde.
Corrine
C
Almeida
Departament of Enginery and Sea Sciences. University of Cabo Verde, Mindelo, São Vicente, Cabo Verde.
Evandro
E
Lopes
Natural History Museum of Funchal, Funchal, Madeira, Portugal.
Ricardo
R
Araújo
Regional Directorate of Sea Affaires, Regional Secretary of Natural Resources, Horta, Açores, Portugal.
Gilberto P
GP
Carreira
Molecular Systematics Laboratory, Department of Biochemistry and Molecular Biology, University Santiago de Compostela, A Coruña, Galicia, Spain.
Manuel
M
Rey-Méndez
Departament of Biology, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.
Nieves
N
González-Henríquez
D000818:Animals; D001267:Atlantic Ocean; D001394:Azores; D001499:Bayes Theorem; D004272:DNA, Mitochondrial / Q000235:genetics; D017753:Ecosystem; D014644:Genetic Variation; D005828:Genetics, Population; D006239:Haplotypes / Q000235:genetics; D008969:Molecular Sequence Data; D009711:Nucleotides / Q000235:genetics; D010802:Phylogeny; D058974:Phylogeography; D012044:Regression Analysis; D013045:Species Specificity; D001468:Thoracica / Q000235:genetics*
D004272:DNA, Mitochondrial; D009711:Nucleotides