title: Investigating the origin of vagrant dusky groupers, Epinephelus marginatus (Lowe, 1834), in coastal waters of Réunion Island.
abstract: Due to their geographic isolation, biotas of oceanic islands are likely influenced by episodic long distance dispersal events, but such observations are scarce. In June 2012, fishermen from Réunion Island caught an unknown specimen of grouper, identified as dusky grouper Epinephelus marginatus (Lowe, 1834). This was highly unexpected considering the large distance of its closest verified occurrence (South Africa, ∼2500km). To identify the origin of this specimen and the mechanisms driving this potential long distance colonization, we combined genetic analyses and hydrodynamic connectivity modeling approaches. Molecular markers and samples from various locations across the distribution range resulted in the identification of three putative source populations. The Réunion specimen clustered genetically with South Africa. The estimated spawning period in relation to the connectivity modeling of larvae showed no possible direct connection between South Africa and Réunion. However, connectivity was predicted through intermediate stepping stone populations likely located around the southern tip of Madagascar, where the occurrence of the species has yet to be verified. The results further highlight the potential role of the cyclone Bingiza (February 2011) in the connection between Madagascar and Réunion. This shows that cyclones may be an important driver in long distance colonization of oceanic islands.
authors.affiliation: Molecular Ecology and Evolution Programme, Department of Genetics, University of Pretoria, Pretoria 0002, South Africa.
authors.forename: Kerry
authors.initials: K
authors.lastname: Reid
authors.affiliation: Institut de Recherche pour le Développement, UMR 228 ESPACE-DEV, Sainte Clotilde, Réunion, France; Institut de Recherche pour le Développement, UMR 9220 ENTROPIE, Sainte Clotilde, Réunion, France.
authors.forename: Estelle
authors.initials: E
authors.lastname: Crochelet
authors.affiliation: Molecular Ecology and Evolution Programme, Department of Genetics, University of Pretoria, Pretoria 0002, South Africa.
authors.forename: Paulette
authors.initials: P
authors.lastname: Bloomer
authors.affiliation: Molecular Ecology and Evolution Programme, Department of Genetics, University of Pretoria, Pretoria 0002, South Africa. Electronic address: thoareau@gmail.com.
authors.forename: Thierry B
authors.initials: TB
authors.lastname: Hoareau
mesh_terms: D000818:Animals; D045303:Cytochromes b / Q000235:genetics; D005838:Genotype; D062312:Islands; D007814:Larva / Q000235:genetics; D008270:Madagascar; D018895:Microsatellite Repeats / Q000235:genetics; D010473:Perciformes / Q000145:classification* / Q000254:growth & development; D010802:Phylogeny; D013019:South Africa
chemical_list: D045303:Cytochromes b
keywords: Colonization; Connectivity; Cyclones; Microsatellites; Range expansion; mtDNA