UNCORRECTED PROOF 2 Ubiquity of Sicyopterus lagocephalus (Teleostei: Gobioidei) 3 and phylogeography of the genus Sicyopterus in the Indo-Pacific 4 area inferred from mitochondrial cytochrome b gene 5 P. Keith a, * , T. Galewski b , G. Cattaneo-Berrebi c , T. Hoareau c,d,e , P. Berrebi c 6 a Muse ´um National d’Histoire Naturelle, Laboratoire d’ichtyologie, CP 26, 43 rue Cuvier, 75231 Paris cedex 05, France 7 b Departments of Paleontology, Phylogeny, and Paleobiology, CC064, Institut des Sciences de l’Evolution (UMR 5554, CNRS), 8 Universite ´ Montpellier II, Place E. Bataillon, 34 095 Montpellier Cedex 5, France 9 c Laboratoire Ecosyste `mes Lagunaires, UMR 5119, cc093, University Montpellier 2, Place Bataillon, 34095 Montpellier, Cedex 05, France 10 d Association Re ´unionnaise pour le De ´veloppement de l’Aquaculture—Centre des Eaux Douces, BP 16, Z.I. Les Sables, 97427 Etang-Sale ´, 11 La Re ´union, France 12 e Laboratoire d’Ecologie Marine, Universite ´ de La Re ´union, 97715 Saint-Denis mes. Cedex 9, France Received 24 January 2005; revised 22 June 2005; accepted 1 July 2005 15 Abstract 16 Sicyopterus lagocephalus is a Gobiidae Sicydiinae (Teleostei) thought to inhabit Indo-Pacific island rivers from Comoros Islands 17 in the Indian Ocean to Australs Islands (French Polynesia) in the Pacific Ocean. Its biological cycle comprises a marine planctonic 18 larval phase of several months allowing it to migrate from island to island, but the other species of the genus, with such a larval 19 stage, have generally a more restricted range and are often endemic. To understand the organisation of a species with such a wide 20 distribution, mtDNA cytochrome b sequences were amplified for 55 specimens of this genus covering most of its distribution range 21 together with six close endemic species and other gobiids used as outgroups. The main result is the confirmation of the ubiquity of 22 S. lagocephalus that occurs over a range of 18,000 km in the Indian and Pacific Oceans. Two clades were identified within this spe- 23 cies, one clustering most of French Polynesian haplotypes and the other clustering most of Mascarene (including Comoros) haplo- 24 types. The overall pattern of distribution and phylogenetic relationship suggests that the lineages leading to endemic species 25 originated earlier than S. lagocephalus. This latter seems to be a secondary migrant species, having colonised both Indian and Pacific 26 Oceans with a few exceptions, situated at the border of the range (Madagascar, Marquesas, Rapa). According to the results, the 27 phylogeny of the Sicyopterus group, the age of the different lineages and the past history of the colonisation of the Indo-Pacific 28 islands are discussed. 29 Ó 2005 Published by Elsevier Inc. 30 Keywords: Sicyopterus lagocephalus; Gobiidae; Molecular phylogeny; Mitochondrial DNA; Dispersion; Pelagic larvae 31 32 1. Introduction 33 In the Indo-Pacific and Caribbean regions, insular 34 river systems are colonised by Gobiidae with a life cycle 35 adapted to the ecological conditions which prevail in 36 these distinctive habitats, which are young oligotrophic 37 rivers subject to extreme climatic and hydrological sea- 38 sonal variation. These species spawn in freshwaters, 39 the free embryos drift downstream to the sea where they 40 undergo a planctonic phase, before returning to the riv- 41 ers to grow and reproduce (Manacop, 1953; Keith, 42 2003), hence they are termed amphidromous (McDo- 1055-7903/$ - see front matter Ó 2005 Published by Elsevier Inc. doi:10.1016/j.ympev.2005.07.023 * Corresponding author. E-mail addresses: keith@mnhn.fr (P. Keith), berrebi@univ- montp2.fr (P. Berrebi). Molecular Phylogenetics and Evolution xxx (2005) xxx–xxx MOLECULAR PHYLOGENETICS AND EVOLUTION www.elsevier.com/locate/ympev YMPEV 1994 No. of Pages 12, DTD = 5.0.1 25 August 2005 Disk Used J. Jayalakshmi (CE) / Anand (TE) ARTICLE IN PRESS