Examination of round sardinella Sardinella aurita Valenciennes, 1847 (Clupeidae) from the Gulf of Tunis (Tunisia) revealed the first local and Mediterranean record of Anthobothrium sp. 1 sensu Jensen & Bullard, 2010 (Tetraphyllidea incertae sedis , Anthobothrium ). Nodular lesions containing multiple larvae were detected at the proximal end of the pyloric caeca, and free plerocercoids were observed in the intestinal lumen and...

How species adapt to diverse environmental conditions is essential for understanding evolution and the maintenance of biodiversity. The European cisco ( Coregonus albula ) is a salmonid that occurs in both fresh and brackish water, and this together with the presence of sympatric spring‐ and autumn‐spawning lacustrine populations provides an opportunity for studying the genetics of adaptation in relation to salinity and timing...

Echinocephalus caniculus n. sp. (Nematoda, Gnathostomatidae Railliet, 1895) was isolated from the spiral valve of the lesser spotted dogfish Scyliorhinus canicula (L.) from the waters off Kalaat El Andalous, North East Tunisia. This new species is mainly characterized by a cephalic bulb armed with 31–39 transverse rows of uncinated hooks, a comparatively long oesophagus, short spicules and the presence of a gubernaculum. The n...

Purpose Endoparasitic nematodes of six harbour porpoises Phocoena phocoena and four grey seals Halichoerus grypus , stranded at the eastern coast of the Baltic Sea in Germany in winter 2019, were analysed in order to identify nematode parasites and to compare with recent studies from the same area. Methods Endoparasitic nematodes were identified by using both morphological and molecular characters. The successfully obtained se...

Anadromous salmonid fishes frequently exhibit strong geographic population structuring. However, population genetic differentiation of Atlantic salmon ( Salmo salar ) at fine geographic scales differs across equivalent spatial extents in different regions. So far, fine-scale genetic differentiation has not been assessed in rivers of the Baltic Sea, a region that contains an evolutionarily distinct Atlantic salmon lineage. Thus...

Using 10 polymorphic microsatellites and 1251 individual samples (some dating back to the early 1980s), genetic structure and effective population size in all native and introduced Swedish populations of the European wels catfish or Silurus glanis were studied. Levels of genetic variability and phylogeographic relationships were compared with data from a previous study of populations in other parts of Europe. The genetically d...

The spatial structure of species is important for their dynamics and evolution, but also for management and conservation. There are numerous ways of inferring spatial structures, and information from multiple methods is becoming more common to examine how different processes shape the spatial structures of species to improve fish management. Here, we investigate the spatial structure of a suite of Baltic Sea fish species based...

Differences in herbivory among woody species can greatly affect the functioning of forest ecosystems, particularly in species‐rich (sub)tropical regions. However, the relative importance of the different plant traits which determine herbivore damage remains unclear. Defence traits can have strong effects on herbivory, but rarely studied geographical range characteristics could complement these effects through evolutionary asso...

There is ample evidence that organisms adapt to their native environment when gene flow is restricted. However, evolution of plastic responses across discrete environments is less well examined. We studied divergence in means and plasticity across wild and hatchery populations of sea‐run brown trout ( Salmo trutta ) in a common garden experiment with two rearing environments (hatchery and a nearly natural experimental stream)....

Previous studies have reported higher levels of divergence for microsatellites than for allozymes in several species, suggested to reflect stabilizing selection on the allozymes. We compared the differentiation patterns of 11 allozyme and nine microsatellite loci using 679 spawning Atlantic herring ( Clupea harengus ) collected in the Baltic and North Seas to test for differential natural selection on these markers. Observed d...

Information on statistical power is critical when planning investigations and evaluating empirical data, but actual power estimates are rarely presented in population genetic studies. We used computer simulations to assess and evaluate power when testing for genetic differentiation at multiple loci through combining test statistics or P values obtained by four different statistical approaches, viz. Pearson's chi‐square, the lo...

The genetic relationships among 337 northern pike ( Esox lucius ) collected from the coastal zone of the central Baltic region and the Finnish islands of Åland were analysed using five microsatellite loci. Spatial structure was delineated using both traditional F ‐statistics and individually based approaches including spatial autocorrelation analysis. Our results indicate that the observed genotypic distribution is incompatibl...