Genetic homogeneity of the invasive lionfish across the Northwestern Atlantic and the Gulf of Mexico based on Single Nucleotide Polymorphisms

Abstract

Despite the devastating impact of the lionfish (Pterois volitans) invasion on NW Atlantic ecosystems, little genetic information about the invasion process is available. We applied Genotyping by Sequencing techniques to identify 1,220 single nucleotide polymorphic sites (SNPs) from 162 lionfish samples collected between 2013 and 2015 from two areas chronologically identified as the first and last invaded areas in US waters: the east coast of Florida and the Gulf of Mexico. We used population genomic analyses, including phylogenetic reconstruction, Bayesian clustering, genetic distances, Discriminant Analyses of Principal Components, and coalescence simulations for detection of outlier SNPs, to understand genetic trends relevant to the lionfish’s long-term persistence. We found no significant differences in genetic structure or diversity between the two areas (FST p-values > 0.01, and t-test p-values > 0.05). In fact, our genomic analyses showed genetic homogeneity, with enough gene flow between the east coast of Florida and Gulf of Mexico to erase previous signals of genetic divergence detected between these areas, secondary spreading, and bottlenecks in the Gulf of Mexico. These findings suggest rapid genetic changes over space and time during the invasion, resulting in one panmictic population with no signs of divergence between areas due to local adaptation.

Population genomics of rapidly invading lionfish in the Caribbean reveals signals of range expansion in the absence of spatial population structure

“…The PCA and F ST analyses of RAD‐seq data presented here, rather, indicate that there is no structure. These findings are similar to those presented in Pérez‐Portela et al () for the Gulf of Mexico. Unfortunately, data reported in Pérez‐Portela et al () were generated using a different restriction enzyme than we used, precluding a direct side‐by‐side analysis of results.…”

“…These findings are similar to those presented in Pérez‐Portela et al () for the Gulf of Mexico. Unfortunately, data reported in Pérez‐Portela et al () were generated using a different restriction enzyme than we used, precluding a direct side‐by‐side analysis of results. The results of both this study and Pérez‐Portela et al () indicate that it is possible that previously reported evidence of population structure among basins seen in mtDNA data could be solely driven by the absence of certain mitochondrial alleles in certain ocean basins.…”

“…The results of both this study and Pérez‐Portela et al () indicate that it is possible that previously reported evidence of population structure among basins seen in mtDNA data could be solely driven by the absence of certain mitochondrial alleles in certain ocean basins. Pérez‐Portela et al () report results that demonstrate the same lack of structure in the Gulf of Mexico, which is likely connected to the greater Caribbean. While structure was not seen in PCA analyses, directionality index results did point to the possibility that certain locations are more or less connected to the rest of the invaded range.…”

“…Unfortunately, data reported in Pérez‐Portela et al () were generated using a different restriction enzyme than we used, precluding a direct side‐by‐side analysis of results. The results of both this study and Pérez‐Portela et al () indicate that it is possible that previously reported evidence of population structure among basins seen in mtDNA data could be solely driven by the absence of certain mitochondrial alleles in certain ocean basins. Pérez‐Portela et al () report results that demonstrate the same lack of structure in the Gulf of Mexico, which is likely connected to the greater Caribbean.…”

“…In one such study, White et al () found evidence of both genetic drift and natural selection in populations of an invasive Bank Vole in Ireland, including patterns of decreased genetic diversity toward the moving range edge. In lionfish, genotype by sequencing (GBS) has been used to generate data for nuclear single nucleotide polymorphism (SNPs) in lionfish populations throughout Florida and the Gulf of Mexico, which is the most recently invaded body of water in that region (Pérez‐Portela et al, ). Using 1,220 SNPs generated with GBS, Pérez‐Portela report a lack of population structure between Florida and the Gulf of Mexico, contradicting previous reports from mitochondrial data regarding a founder event when the Gulf of Mexico was invaded.…”