DeWoody J Andrew, Fletcher Dean E, Wilkins S David, Nelson William S, Avise John C
Department of Genetics, University of Georgia, Athens, Georgia, 30602.
Savannah River Ecology Laboratory, Drawer E, Aiken, South Carolina, 29802.
Evolution. 1998 Dec;52(6):1802-1810. doi: 10.1111/j.1558-5646.1998.tb02257.x.
Despite a great diversity of reproductive behaviors in fishes, few studies have examined the genetic consequences of alternative reproductive tactics. Here we develop and employ microsatellite markers to assess genetic paternity and maternity of progeny cohorts in a population of redbreast sunfish (Lepomis auritus), a species in which males build and tend nests. Nearly 1000 progeny from 25 nests, plus nest-attendant males and nearby adults, were genotyped at microsatellite loci that displayed more than 18 alleles each. The genetic data demonstrate that multiple females (at least two to six) spawned in each nest, their offspring were spatially dispersed across a nest, and more than 90% of the young were sired by the attendant male. However, about 40% of the nests also showed genetic evidence of low-level reproductive parasitism, and two nests were tended by males that had fathered none of the sampled offspring. Genetically deduced reproductive behaviors in this population of redbreast sunfish contrast with those reported previously in bluegill sunfish (L. macrochirus) wherein heteromorphic males specialized for parasitism or for parental care coexist in high frequency. Thus, nest-parasitic reproductive behaviors in fishes appear to be evolutionary labile.
尽管鱼类的繁殖行为具有高度多样性，但很少有研究探讨替代繁殖策略的遗传后果。在此，我们开发并应用微卫星标记来评估红胸太阳鱼（Lepomis auritus）种群中子代群体的遗传父系和母系，该物种中雄性会建造并照料巢穴。对来自25个巢穴的近1000个子代，以及巢穴照料雄性和附近成年个体，在每个都显示出超过18个等位基因的微卫星位点进行基因分型。遗传数据表明，每个巢穴中有多个雌性（至少两到六个）产卵，它们的后代在巢穴中呈空间分散分布，并且超过90%的幼鱼是由照料雄性所生。然而，约40%的巢穴也显示出低水平繁殖寄生的遗传证据，并且有两个巢穴由未生育任何所采样后代的雄性照料。在这个红胸太阳鱼种群中通过遗传推断出的繁殖行为与先前在蓝鳃太阳鱼（L. macrochirus）中报道的行为形成对比，在蓝鳃太阳鱼中，专门用于寄生或亲代抚育的异形雄性以高频率共存。因此，鱼类中的巢穴寄生繁殖行为似乎在进化上是不稳定的。
