Data from: Seascape continuity plays an important role in determining patterns of spatial genetic structure in a coral reef fish

Detecting patterns of spatial genetic structure (SGS) can help identify
intrinsic and extrinsic barriers to gene flow within metapopulations. For
marine organisms such as coral reef fishes, identifying these barriers is
critical to predicting evolutionary dynamics and demarcating
evolutionarily significant units for conservation. In this study, we
adopted an alternative hypothesis-testing framework to identify the
patterns and predictors of SGS in the Caribbean reef fish Elacatinus lori.
First, genetic structure was estimated using nuclear microsatellites and
mitochondrial cytochrome b sequences. Next, clustering and network
analyses were applied to visualize patterns of SGS. Finally, logistic
regressions and linear mixed models were used to identify the predictors
of SGS. Both sets of markers revealed low global structure: mitochondrial
ΦST = 0.12, microsatellite FST = 0.0056. However, there was high
variability among pairwise estimates, ranging from no differentiation
between sites on contiguous reef (ΦST = 0) to strong differentiation
between sites separated by ocean expanses ≥ 20 km (maximum ΦST = 0.65).
Genetic clustering and statistical analyses provided additional support
for the hypothesis that seascape discontinuity, represented by oceanic
breaks between patches of reef habitat, is a key predictor of SGS in E.
lori. Notably, the estimated patterns and predictors of SGS were
consistent between both sets of markers. Combined with previous studies of
dispersal in E. lori, these results suggest that the interaction between
seascape continuity and the dispersal kernel plays an important role in
determining genetic connectivity within metapopulations.