Habitat Discontinuities Separate Genetically Divergent Populations of a Rocky Shore Marine Fish

Abstract

Habitat fragmentation has been suggested to be responsible for major genetic differentiations in a range of marine organisms. In this study, we combined genetic data and environmental information to unravel the relative role of geography and habitat heterogeneity on patterns of genetic population structure of corkwing wrasse (Symphodus melops), a rocky shore species at the northern limit of its distribution range in Scandinavia. Our results revealed a major genetic break separating populations inhabiting the western and southern coasts of Norway. This genetic break coincides with the longest stretch of sand in the whole study area, suggesting habitat fragmentation as a major driver of genetic differentiation of this obligate rocky shore benthic fish in Scandinavia. The complex fjords systems extending along the western coast of Norway appeared responsible for further regional genetic structuring. Our findings indicate that habitat discontinuities may lead to significant genetic fragmentation over short geographical distances, even for marine species with a pelagic larval phase, as for this rocky shore fish.

Signatures of selection for bonamiosis resistance in European flat oyster (Ostrea edulis): New genomic tools for breeding programs and management of natural resources

“…Marine species typically show low structuring due to high effective population sizes and high gene flow facilitated by the absence of physical barriers, which lead to high genomic homogenization across populations (Vandamme et al, ; Vilas et al, ). However, habitat shifts (ecotones) and oceanic currents/ fronts have been demonstrated to act as practical barriers (Blanco‐González, Knutsen, & Jorde, ; Vera et al, ), and particularly, natural selection in response to abiotic and biotic factors has been demonstrated to actively shaping specific genomic regions related to adaption even in a context of high gene flow (Vandamme et al, ; Vilas, Bouza, Vera, Millán, & Martínez, ; Vilas et al, ). The ability to distinguish between neutral and adaptive genetic variation has become a central issue in evolutionary biology, as it would allow the understanding of population structure in both historical/demographic and adaptive terms (Bernatchez, ; Nielsen, Hemmer‐Hansen, Larsen, & Bekkevold, ), thus being an essential information for sustainable fisheries management.…”

Parallel evolution and adaptation to environmental factors in a marine flatfish: Implications for fisheries and aquaculture management of the turbot (Scophthalmus maximus)

“…However, various factors can bring about genetic differentiation, such as habitat shifts (ecotones) and oceanic currents (Blanco‐Gonzalez, Knutsen, & Jorde, 2016; Galarza et al., 2009; Nielsen, Nielsen, Meldrup, & Hansen, 2004; Vera et al., 2016a), and natural selection in response to environmental variation (Milano et al., 2014; Vandamme et al., 2014; Vilas, Bouza, Vera, Millán, & Martínez, 2010; Vilas et al., 2015). Distinguishing between neutral and adaptive genetic variation has become a central issue in evolutionary biology, allowing for understanding of population structure in both historical/demographic and adaptive terms (Bernatchez, 2016; Nielsen, Hemmer‐Hansen, Larsen, & Bekkevold, 2009), thereby providing essential information for the conservation and management of wild populations.…”

Interbreeding between local and translocated populations of a cleaner fish in an experimental mesocosm predicts risk of disrupted local adaptation

“…The mesocosm basin has a capacity of approximately 2,000 m 3 , a surface area of 660 m 2 , a maximum depth of 5 m, and the seawater is pumped up from 75 m depth (Moksness, 1982). On June 24, 2014, 167 adults from Norheimsund, on the west coast of Norway (for location in a map see Blanco Gonzalez et al, 2016), were collected using baited wrasse pots by a local fisherman and transported alive to Flødevigen. On June 24, 2014, 167 adults from Norheimsund, on the west coast of Norway (for location in a map see Blanco Gonzalez et al, 2016), were collected using baited wrasse pots by a local fisherman and transported alive to Flødevigen.…”