title: Phylogeography of two moray eels indicates high dispersal throughout the indo-pacific.
abstract: Reef fishes disperse primarily as oceanic "pelagic" larvae, and debate continues over the extent of this dispersal, with recent evidence for geographically restricted (closed) populations in some species. In contrast, moray eels have the longest pelagic larval stages among reef fishes, possibly providing opportunities to disperse over great distances. We test this prediction by measuring mitochondrial DNA (mtDNA) and nuclear DNA variation in 2 species of moray eels, Gymnothorax undulatus (N = 165) and G. flavimarginatus (N = 124), sampled at 14-15 locations across the Indo-Pacific. The mtDNA data comprise 632 bp of cytochrome b and 596 bp of cytochrome oxidase I. Nuclear markers include 2 recombination-activating loci (421 bp of RAG-1 and 754 bp of RAG-2). Analyses of molecular variance and Mantel tests indicate little or no genetic differentiation, and no isolation by distance, across 22 000 km of the Indo-Pacific. We estimate that mitochondrial genetic variation coalesces within the past about 2.3 million years (My) for G. flavimarginatus and within the past about 5.9 My for G. undulatus. Permutation tests of geographic distance on the mitochondrial haplotype networks indicate recent range expansions for some younger haplotypes (estimated within approximately 600 000 years) and episodic fragmentation of populations at times of low sea level. Our results support the predictions that the extended larval durations of moray eels enable ocean-wide genetic continuity of populations. This is the first phylogeographic survey of the moray eels, and morays are the first reef fishes known to be genetically homogeneous across the entire Indo-Pacific.
authors.affiliation: Department of Biology, Washington University in Saint Louis, Box 1137, One Brookings Drive, Saint Louis, MO 63130, USA. jsreece@wustl.edu
authors.forename: Joshua S
authors.initials: JS
authors.lastname: Reece
authors.forename: Brian W
authors.initials: BW
authors.lastname: Bowen
authors.forename: Kavita
authors.initials: K
authors.lastname: Joshi
authors.forename: Vadim
authors.initials: V
authors.lastname: Goz
authors.forename: Allan
authors.initials: A
authors.lastname: Larson
mesh_terms: D025041:Animal Migration; D000818:Animals; D004272:DNA, Mitochondrial / Q000378:metabolism; D004524:Eels / Q000235:genetics*; D003576:Electron Transport Complex IV / Q000235:genetics; D051456:Gene Flow; D040961:Genetic Drift; D005828:Genetics, Population; D005843:Geography; D007814:Larva / Q000378:metabolism; D010140:Pacific Ocean; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial; D003576:Electron Transport Complex IV