Singer A, Kvarnemo C, Lindström K, Svensson O
Department of Zoology, Stockholm University, Stockholm, Sweden.
J Evol Biol. 2006 Sep;19(5):1641-50. doi: 10.1111/j.1420-9101.2006.01114.x.
Pomatoschistus minutus show paternal care in a resource defence mating system. We investigated the effect of nest-site availability on parasitic spawning. Each experimental pool contained four potentially nest-building males, four females and nests-sites in shortage (2) or excess (6). Both treatments were conducted in two populations; one with natural nest-sites in excess, one with a nest-site shortage. Microsatellite-DNA revealed that all nest-holders had fertilized most of the eggs they tended. Yet, 35% of the nests contained eggs fertilized by another male and 14.4% of the males had performed parasitic spawning. There was no site or treatment effect. Several females spawned in two nests, which coincided with parasitic spawnings, suggesting a cost to the nest-holder in terms of lost mating success. Nest-holders with and without eggs and non-nesting males all spawned parasitically, generating a significantly lower opportunity for sexual selection compared to if there had been no parasitic spawning.
细纹鳚在资源防御交配系统中表现出亲代抚育行为。我们研究了巢穴位置可用性对寄生性产卵的影响。每个实验池中有四只可能筑巢的雄性、四只雌性以及短缺（2个）或充足（6个）的巢穴位置。两种处理方式都在两个种群中进行；一个种群自然巢穴位置充足，另一个种群巢穴位置短缺。微卫星DNA显示，所有巢穴所有者使它们照料的大多数卵受精。然而，35%的巢穴中含有由另一只雄性受精的卵，14.4%的雄性进行了寄生性产卵。不存在位置或处理方式的影响。几只雌性在两个巢穴中产卵，这与寄生性产卵同时发生，这表明对于巢穴所有者来说在交配成功率损失方面存在成本。有卵和无卵的巢穴所有者以及非筑巢雄性都进行了寄生性产卵，与不存在寄生性产卵的情况相比，性选择的机会显著降低。
