Recent behavioural studies on fish have emphasized the role of ultraviolet (UV) wavelengths in mate choice. We performed female mate choice experiments, focusing on the UV wavelength range, with the three-spined stickleback, Gasterosteus aculeatus, a species in which the role of visually guided behaviour in the human-visible wavelength range (400–700 nm) has been well studied. Ripe female stick...

The three-spined stickleback (Gasterosteus aculeatus L., hereafter 'stickleback') is a common mesopredatory fish in marine, coastal and freshwater areas. In large parts of the Baltic Sea, stickleback densities have increased >10-fold during the last decades, and it is now one of the dominating fish species both in terms of biomass and effects on lower trophic levels. Still, relatively little is...

Body size is a highly variable trait among geographically separated populations. Size-assortative reproductive isolation has been linked to recent adaptive radiations of threespine stickleback (Gasterosteus aculeatus) into freshwater, but the genetic basis of the commonly found size difference between anadromous and derived lacustrine sticklebacks has not been tested. We studied the genetic bas...

Although crucial for the understanding of adaptive evolution, genetically resolved examples of local adaptation are rare. To maximize survival and reproduction in their local environment, hosts should resist their local parasites and pathogens. The major histocompatibility complex (MHC) with its key function in parasite resistance represents an ideal candidate to investigate parasite-mediated l...

In comparison with terrestrial and freshwater ecosystems, information about speciation modes and the role of selection in marine environments is scarce. Recent studies have indicated that spectral adaptation could play an important role in the diversification of marine species flocks. Natural selection influences specific amino acids (AAs) that are involved in the spectral tuning mechanism of v...

The aim of this study was to develop an enzyme-linked immunosorbent (ELISA) assay to quantify spiggin in the three-spined stickleback. Spiggin is a glue protein produced in the kidney of male three-spined stickleback under the control of androgens during the breeding period. Disturbances of spiggin production in male fish and abnormal induction of spiggin in female fish are considered as valuab...