title: Evolution of diadromy in fish: insights from a tropical genus (Kuhlia species).
abstract: Diadromous species undergo regular migration between fresh and marine waters. This behavior is found in many species, including fish, mollusks, and crustaceans, some of which are commercially valuable species. Several attempts to trace the evolution of this behavior have been made in Salmonidae and Galaxiidae, but ambiguous phylogenies and multiple character state changes prevented unequivocal conclusions. The Kuhliidae family consists of 12 fish species that inhabit tropical islands in the Indo-Pacific region. The species have marine, partially catadromous, or fully catadromous life histories (i.e., they migrate from rivers to the sea to reproduce). The evolution of migratory behavior was traced on a well-resolved phylogeny. Catadromous Kuhlia species were basal, and partially catadromous and marine species formed derived monophyletic groups. This is, to our knowledge, the first time that a clear origin and polarity for the diadromous character has been demonstrated. We propose that the relative lack of resources in tropical, inshore, marine habitats and the ephemeral and isolated nature of freshwater environments of tropical islands, combined with phenotypic plasticity of migratory traits, play key roles in driving the evolution of diadromy in the Kuhliidae and probably in other groups. This work is an important starting point to understand the role of diadromy in speciation and adaptation in unstable habitats.
authors.affiliation: Muséum National d'Histoire Naturelle, Milieux et Peuplements Aquatiques, Unité de Mixte de Recherche (UMR) 7208, Ichtyologie, 57 rue Cuvier, CP026, Paris 75231, France. pierre.feutry@cdu.edu.au
authors.forename: Pierre
authors.initials: P
authors.lastname: Feutry
authors.forename: Magalie
authors.initials: M
authors.lastname: Castelin
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Ovenden
authors.forename: Agnès
authors.initials: A
authors.lastname: Dettaï
authors.forename: Tony
authors.initials: T
authors.lastname: Robinet
authors.forename: Corinne
authors.initials: C
authors.lastname: Cruaud
authors.forename: Philippe
authors.initials: P
authors.lastname: Keith
mesh_terms: D025041:Animal Migration; D000818:Animals; D005075:Biological Evolution; D004777:Environment; D008969:Molecular Sequence Data; D010473:Perciformes / Q000235:genetics / Q000502:physiology*; D010802:Phylogeny; D012098:Reproduction; D017422:Sequence Analysis, DNA; D017385:Sequence Homology