Haddeland Peter Jørgen, Junge Claudia, Serbezov Dimitar, Vøllestad Leif Asbjørn
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.
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.
PLoS One. 2015 Mar 20;10(3):e0122032. doi: 10.1371/journal.pone.0122032. eCollection 2015.
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.
了解一个物种的繁殖系统对于理解繁殖成功率的个体差异很重要。繁殖成功率的巨大差异以及由此产生的繁殖偏态对繁殖者的有效数量进而对长期有效种群大小（Ne）有强烈影响。鱼类，特别是鲑科鱼类，表现出多种多样的繁殖系统。然而，一般来说，野生环境中的繁殖系统很少被详细研究。在这里，我们使用基于19个多态微卫星位点基因分型的亲权鉴定方法，研究了挪威一条小溪中春季产卵的欧洲茴鱼（Thymallus thymallus）的繁殖系统。总共对895条茴鱼幼鱼和154条成熟茴鱼（57条雌性和97条雄性）进行了基因分型。共有466个后代被确定了父亲、母亲或双亲对，置信度为90%或更高。成功繁殖的雄性平均有11.9±13.3（标准差）个后代，平均有2.1±1.2个配偶，而成功繁殖的雌性平均有9.5±12.8个后代和2.3±1.5个配偶。配偶较多的亲本也会产生更多的后代。因此，这条小溪中的茴鱼繁殖系统显示出一种多配偶制的繁殖系统，这与许多其他鲑科鱼类所观察到的情况相似。本研究因此明确证实了欧洲茴鱼的多配偶制繁殖系统。这一知识对于管理该物种的种群至关重要，在过去几十年里，该物种在其整个分布范围内的局部种群数量都大幅下降。
