论文部分内容阅读
Here we provide an example of simultaneous polyandry based on genetic evidence inFeirana kangxianensis. This stream-dwelling species occurs only in Kangxian County, southern Gansu Province, where it is sympatric with its sibling speciesF. quadranus. During the breeding season the sex ratio ofF. kangxianensis was marginally female-biased (44♂:59♀) and the encounter rate in a relatively pristine habitat was signiifcantly higher than that in heavily quarried habitats (9.6 ± 4.8 indiv./kmvs. 3.2 ± 2.5 indiv./km). Three egg masses containing an average of 698 eggs were deposited on the underside of one or two adjacent lfat rocks, 6.0–10.0 cm under the water surface and 1.0–3.5 cm above the streambed. Using Bayesian sibship clustering of nine polymorphic microsatellite genotypes, two females were detected as group-spawning in one oviposition site, with three males fertilizing each female’s eggs simultaneously. We also discuss the conservation requirements of this range-restricted species and the evolutionary implication of its unusual reproductive strategy.