title: Genetic parentage analysis confirms a polygynandrous breeding system in the European grayling (Thymallus thymallus).
abstract: Knowing the breeding system of a species is important in order to understand individual variation in reproductive success. Large variation in reproductive success and thus reproductive skew strongly impacts on the effective number of breeders and thus the long-term effective population size (Ne). Fishes, in particular species belonging to the salmonid family, exhibit a wide diversity of breeding systems. In general, however, breeding systems are rarely studied in detail in the wild. Here we examine the breeding system of the spring-spawning European grayling Thymallus thymallus from a small Norwegian stream using parentage assignment based on the genotyping of 19 polymorphic microsatellite loci. In total 895 individual grayling fry and 154 mature grayling (57 females and 97 males) were genotyped. A total of 466 offspring were assigned a father, a mother, or a parent pair with a confidence of 90% or higher. Successfully reproducing males had on average 11.9 ± 13.3 (SD) offspring with on average 2.1 ± 1.2 partners, whereas successful females had on average 9.5 ± 12.8 offspring and 2.3 ± 1.5 partners. Parents with more partners also produced more offspring. Thus the grayling breeding system within this small stream revealed a polygynandrous breeding system, similar to what has been observed for many other salmonid fish species. The present study thus unambiguously corroborates a polygynadrous breeding system in the European grayling. This knowledge is critical for managing populations of this species, which has suffered significant local population declines throughout its range over the last several decades.
authors: Center for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, P. O. Box 1066, Blindern, 0316, Oslo, Norway; Department of Genetic Kinship and Identity, Norwegian Institute of Public Health, P. O. Box 4040, Nydalen, 0403, Oslo, Norway.
authors: Peter Jørgen
authors: PJ
authors: Haddeland
authors: Center for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, P. O. Box 1066, Blindern, 0316, Oslo, Norway; Southern Seas Ecology Laboratories, DP418, School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia.
authors: Claudia
authors: C
authors: Junge
authors: Center for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, P. O. Box 1066, Blindern, 0316, Oslo, Norway; National Agency of Fisheries and Aquaculture, 17 Hristo Botev Blvd, 1606, Sofia, Bulgaria.
authors: Dimitar
authors: D
authors: Serbezov
authors: Center for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, P. O. Box 1066, Blindern, 0316, Oslo, Norway.
authors: Leif Asbjørn
authors: LA
authors: Vøllestad
mesh_terms: D000818:Animals; D001947:Breeding; D005260:Female; D056426:Genetic Loci; D014644:Genetic Variation; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D012487:Salmonidae / Q000235:genetics*