Multilocus phylogeography of the sea snake Hydrophis curtus reveals historical vicariance and cryptic lineage diversity

ANDERSSubmitted: 13 December 2013Accepted: 16 June 2014doi:10.1111/zsc.12070Ukuwela, K. D. B., de Silva, A., Mumpuni, Fry, B. G. & Sanders, K. L. (2014). Multilocusphylogeography of the sea snake Hydrophis curtus reveals historical vicariance and crypticlineage diversity. — Zoologica Scripta, 00, 000–000.The Indo-Australian archipelago (IAA) supports the world’s highest diversity of marine fish,invertebrates and reptiles. Many of the marine fish and invertebrates show congruent phy-logeographic patterns, supporting a view that the region’s complex geo-climatic history hasplayed an important role in generating its exceptional biodiversity. Here, we examine popu-lation genetic structure of the viviparous sea snake, Hydrophis curtus, to assess how past andpresent barriers to gene flow in the IAA have contributed to genetic and species diversity ina fully marine reptile. Mitochondrial and anonymous nuclear sequences and ten microsatel-lite loci were used to identify patterns of historical genetic structure and population expan-sion, reconstruct dated genealogies and assess levels of recent gene flow. These markersrevealed strong concordant geographic structure within H. curtus with a prominent geneticbreak between populations broadly distributed in the Indian Ocean and the West Pacific.These populations were estimated to have diverged in the late Pliocene or early Pleistocene,and microsatellite admixture analyses suggested limited recent gene flow between themdespite the current lack of barriers to dispersal, indicating possible cryptic species. Subse-quent divergence in the mid–late Pleistocene was detected within the West Pacific cladeamong the populations in the Phuket-Thailand region, South-East Asia and Australia, andtwo of these populations also showed genetic signals of recent range expansions. Our resultsshow that climatic fluctuations during the Plio-Pleistocene generated high levels of crypticgenetic diversity in H. curtus, and add to similar findings for diverse other marine groups inthe IAA.Corresponding author: Kanishka D. B. Ukuwela, School of Earth and Environmental Sciences,University of Adelaide, Darling Building, Adelaide, SA 5005, Australia. E-mail: kanishkauku@yahoo.comKanishka D. B. Ukuwela, School of Earth and Environmental Sciences, University of Adelaide,Darling Building, Adelaide, SA 5005, Australia. E-mail: kanishkauku@yahoo.comAnslem de Silva, Amphibia and Reptile research Organization of Sri Lanka, 15/1, Dolosbage Rd.,Gampola, Sri Lanka. E-mail: kalds@sltnet.lkMumpuni, Museum of Zoology Bogor, Puslit Biology-LIPI, Cibinong, Indonesia. E-mail: mumpuni@lipi.go.idBryan G. Fry, Venom Evolution Laboratory, School of Biological Sciences, University of Queensland,Brisbane, QLD 4072, Australia. E-mail: bgfry@uq.edu.auKate L. Sanders, School of Earth and Environmental Sciences, University of Adelaide, DarlingBuilding, Adelaide, SA 5005, Australia. E-mail: kate.sanders@adelaide.edu.au