Non-random mating within an Island rookery of Hawaiian hawksbill turtles: demographic discontinuity at a small coastline scale.

Hawksbill sea turtles () from the Hawaiian archipelago form a small and genetically isolated population, consisting of only a few tens of individuals breeding annually. Most females nest on the island of Hawai'i, but little is known about the demographics of this rookery. This study used genetic relatedness, inferred from 135 microhaplotype markers, to determine breeding sex-ratios, estimate female nesting frequency and assess relationships between individuals nesting on different beaches.

Resolving fine-scale population structure and fishery exploitation using sequenced microsatellites in a northern fish.

The resiliency of populations and species to environmental change is dependent on the maintenance of genetic diversity, and as such, quantifying diversity is central to combating ongoing widespread reductions in biodiversity. With the advent of next-generation sequencing, several methods now exist for resolving fine-scale population structure, but the comparative performance of these methods for genetic assignment has rarely been tested. Here, we evaluate the performance of sequenced microsatellites and a single nucleotide polymorphism (SNP) array to resolve fine-scale population structure in a critically important salmonid in north eastern Canada, Arctic Charr ().

Chromosome polymorphisms track trans-Atlantic divergence and secondary contact in Atlantic salmon.

Pleistocene glaciations drove repeated range contractions and expansions shaping contemporary intraspecific diversity. Atlantic salmon (Salmo salar) in the western and eastern Atlantic diverged >600,000 years before present, with the two lineages isolated in different southern refugia during glacial maxima, driving trans-Atlantic genomic and karyotypic divergence. Here, we investigate the genomic consequences of glacial isolation and trans-Atlantic secondary contact using 108,870 single nucleotide polymorphisms genotyped in 80 North American and European populations.

Environmental extremes drive population structure at the northern range limit of Atlantic salmon in North America.

Conservation of exploited species requires an understanding of both genetic diversity and the dominant structuring forces, particularly near range limits, where climatic variation can drive rapid expansions or contractions of geographic range. Here, we examine population structure and landscape associations in Atlantic salmon (Salmo salar) across a heterogeneous landscape near the northern range limit in Labrador, Canada. Analysis of two amplicon-based data sets containing 101 microsatellites and 376 single nucleotide polymorphisms (SNPs) from 35 locations revealed clear differentiation between populations spawning in rivers flowing into a large marine embayment (Lake Melville) compared to coastal populations.

Annotated mitochondrial genome assemblies for two sand lances (genus: Ammodytes) from the northwest Atlantic.

Complete mitochondrial genomes of two northwest Atlantic sand lances (Ammodytes americanus and Ammodytes dubius) were sequenced, assembled, and annotated. Both genomes were 16 519 bp in length and were differentiated by a genetic distance of only 0.01.

Complete mitochondrial genomes for Icelus spatula, Aspidophoroides olrikii and Leptoclinus maculatus: pan-Arctic marine fishes from Canadian waters.

Three Arctic marine fishes Icelus spatula, Aspidophoroides olrikii and Leptoclinus maculatus have been identified as target species for investigating the effects of ocean warming on population patterns in high-latitude marine habitats around Canada. In preparation for this research, we have resolved whole mitochondrial genome sequences of 16 384, 17 200 and 16 384 bp for each species, respectively. GC content for each species was 47.

Limited contemporary gene flow and high self-replenishment drives peripheral isolation in an endemic coral reef fish.

Extensive ongoing degradation of coral reef habitats worldwide has lead to declines in abundance of coral reef fishes and local extinction of some species. Those most vulnerable are ecological specialists and endemic species. Determining connectivity between locations is vital to understanding recovery and long-term persistence of these species following local extinction.

Observations of migrant exchange and mixing in a coral reef fish metapopulation link scales of marine population connectivity.

Much progress has been made toward understanding marine metapopulation dynamics, largely because of multilocus microsatellite surveys able to connect related individuals within the metapopulation. However, most studies are focused on small spatial scales, tens of kilometers, while demographic exchange at larger spatial scales remains poorly documented. Additionally, many small-scale demographic studies conflict with broad-scale phylogeographic patterns concerning levels of marine population connectivity, highlighting a need for data on more intermediate scales.

Limited ecological population connectivity suggests low demands on self-recruitment in a tropical inshore marine fish (Eleutheronema tetradactylum: Polynemidae).

The diversity of geographic scales at which marine organisms display genetic variation mirrors the biophysical and ecological complexity of dispersal by pelagic larvae. Yet little is known about the effect of larval ecology on genetic population patterns, partly because detailed data of larval ecology do not yet exist for most taxa. One species for which this data is available is Eleutheronema tetradactylum, a tropical Indo-West Pacific shorefish.

High population connectivity across the Indo-Pacific: Congruent lack of phylogeographic structure in three reef fish congeners.

We used the mitochondrial control region and a comparative approach to study the genetic population structure of two surgeonfishes, Naso brevirostris and Naso unicornis, across their Indo-central Pacific ranges. Our purpose was to compare our results with those of a previous study of Naso vlamingii [Klanten, S.O.