02266nas a2200157   4500008004100000245014100041210006900182260001600251300001200267490000800279520172000287100001902007700001702026700001702043856004802060       2009                        eng d00aHigh gene flow due to pelagic larval dispersal among South Pacific archipelagos in two amphidromous gastropods (Neritomorpha: Neritidae)0 aHigh gene flow due to pelagic larval dispersal among South Pacif  c2009 Oct 21  a563-5720 v1043 aThe freshwater stream fauna of tropical oceanic islands is dominated by amphidromous species, whose larvae are transported to the ocean and develop in the plankton before recruiting back to freshwater habitat as juveniles. Because stream habitat is relatively scarce and unstable on oceanic islands, this life history would seem to favor either the retention of larvae to their natal streams, or the ability to delay metamorphosis until new habitat is encountered. To distinguish between these hypotheses, we used population genetic methods to estimate larval dispersal among five South Pacific archipelagos in two amphidromous species of Neritid gastropod (Neritina canalis and Neripteron dilatatus). Sequence data from mitochondrial cytochrome oxidase I (COI) revealed that neither species is genetically structured throughout the Western Pacific, suggesting that their larvae have a pelagic larval duration (PLD) of at least 8 weeks, longer than many marine species. In addition, the two species have recently colonized isolated Central Pacific archipelagos in three independent events. Since colonization, there has been little or no gene flow between the Western and Central Pacific archipelagos in N. canalis, and high levels of gene flow across the same region in N. dilatatus. Both species show departures from neutrality and recent dates for colonization of the Central Pacific archipelagos, which is consistent with frequent extinction and recolonization of stream populations in this area. Similar results from other amphidromous species suggest that unstable freshwater habitats promote long-distance dispersal capabilities.Heredity advance online publication, 21 October 2009; doi:10.1038/hdy.2009.138.1 aCrandall, E, D1 aTaffel, J, R1 aBarber, P, H  uhttps://neritopsine.myspecies.info/node/22901212nas a2200133   4500008004100000245008600041210006900127260001600196300001200212490000600224520078100230100001901011856004801030       2009                        eng d00aHitchhiking behaviour in the obligatory upstream migration of amphidromous snails0 aHitchhiking behaviour in the obligatory upstream migration of am  c2009 Aug 23  a465-4680 v53 aMigratory animals endure high stress during long-distance travel in order to benefit from spatio-temporally fluctuating resources, including food and shelter or from colonization of unoccupied habitats. Along with some fishes and shrimps, nerite snails in tropical to temperate freshwater systems are examples of amphidromous animals that migrate upstream for growth and reproduction after a marine larval phase. Here I report, to my knowledge, the first example of 'hitchhiking' behaviour in the obligatory migration of animals: the nerite snail Neritina asperulata appears to travel several kilometres as minute juveniles by firmly attaching to the shells of congeneric, subadult snails in streams of Melanesian Islands, presumably to increase the success rate of migration.1 aKano, Yasunori  uhttps://neritopsine.myspecies.info/node/230