Polar cod ( Boreogadus saida ) functions as a key species in the Arctic food web and is one of the most abundant Arctic fishes. Despite its ecological importance, the feeding ecology of juveniles sampled under the sea ice is unknown. In November 2019, at the onset of sea ice formation, sea-ice associated polar cod and zooplankton samples were collected in the Beaufort and Chukchi seas. Stomach contents were highly digested and...

Information on connectivity and genetic structure of marine organisms remains sparse in frontier ecosystems such as the Arctic Ocean. Filling these knowledge gaps becomes increasingly urgent, as the Arctic is undergoing rapid physical, ecological and socio‐economic changes. The abundant and widely distributed polar cod ( Boreogadus saida ) is highly adapted to Arctic waters, and its larvae and juveniles live in close associati...

Aim The formation history of Africa's current river basins remains largely unknown. In order to date changes in landscape and climate, we studied the biogeography of the African freshwater fish with the largest natural distribution. We also validated biogeographical units. Location Continental Africa. Taxon Clarias gariepinus sl. Methods We investigated mitochondrial cyt b sequences of 443 individuals from 97 localities, using...

Unravelling the factors shaping the genetic structure of mobile marine species is challenging due to the high potential for gene flow. However, genetic inference can be greatly enhanced by increasing the genomic, geographical or environmental resolution of population genetic studies. Here, we investigated the population structure of turbot ( S cophthalmus maximus ) by screening 17 random and gene‐linked markers in 999 individu...

Genes with major phenotypic effects facilitate quantifying the contribution of genetic vs. plastic effects to adaptive divergence. A classical example is Ectodysplasin ( Eda ), the major gene controlling lateral plate phenotype in three‐spined stickleback. Completely plated marine stickleback populations evolved repeatedly towards low‐plated freshwater populations, representing a prime example of parallel evolution by natural...

Aim The Pleistocene glaciations were the most significant historical event during the evolutionary life span of most extant species. However, little is known about the consequences of these climate changes for the distribution and demography of marine animals of the north‐eastern Atlantic. The present study focuses on the phylogeographic and demographic patterns of the sand goby, Pomatoschistus minutus (Teleostei: Gobiidae), a...

Life history traits of highly vagile marine species, such as adult reproductive success and larval dispersal, are strongly determined by oceanographic and climatic forces. Nevertheless, marine organisms may show restricted dispersal in time and space. Patterns of isolation by distance (IBD) have been repeatedly observed in marine species. If spawning time is a function of geographical location, temporal and spatial isolation,...

The phylogeographical patterns of a small marine fish, the common goby, Pomatoschistus microps, were assessed at 12 sites along the northeastern Atlantic coasts and the western Mediterranean Sea. A combination of two genetic markers was employed: cellulose acetate allozyme electrophoresis (CAGE) and sequence analysis of a 289 bp fragment of the mitochondrial locus cytochrome b . Both markers were congruent in revealing signifi...

The distribution of genetic diversity at 10 highly polymorphic microsatellite loci within the European freshwater fish, Cottus gobio , L. was examined. The sampling range comprised a large geographical scale including lineages known to be highly divergent at both mitochondrial DNA (mtDNA) and allozymes. An analysis of genetic variability within populations showed that expected heterozygosity and allelic richness could be expla...