Local adaptation despite high gene flow in the waterfall‐climbing Hawaiian goby,Sicyopterus stimpsoni

• DOI: 10.1111/mec.13016
• Publication Date: 2014-11-28T21:01:13Z
• Authors: K. N. Moody; S. N. Hunter; M. J. Childress; R. W. Blob; H. L. Schoenfuss; M. J. Blum; M. B. Ptacek
• Keywords: Waterfall; Climbing; Local adaptation

Abstract Environmental heterogeneity can promote the emergence of locally adapted phenotypes among subpopulations a species, whereas gene flow result in phenotypic and genotypic homogenization. For organisms like amphidromous fishes that change habitats during their life history, balance between selection migration shift through ontogeny, making likelihood local adaptation difficult to predict. In Hawaiian waterfall‐climbing gobies, it has been hypothesized larval mixing oceanic dispersal counters contrasting topographic features streams, slope gradient, select for predator avoidance or climbing ability juvenile recruits. To test this hypothesis, we used morphological traits neutral genetic markers compare distributions recruiting juveniles adult goby, Sicyopterus stimpsoni, from islands Hawai'i Kaua'i. We found body shape is significantly different streams with slopes trait divergence tracked stream topography more so than measures subpopulation differentiation. Although no evidence population differentiation was observed subpopulations, low but significant levels spatially temporally variable cohorts, which correlated divergence. Such pattern consistent chaotic patchiness arising sources recruits streams. Thus, at least S. stimpsoni , combination variation settlement cohorts space time coupled strong postsettlement on as they migrate upstream provides opportunity environments despite high flow.