Unidade de Investigação em Eco-Etologia, Instituto Superior de Psicologia Aplicada, 1149-041 Lisboa, Portugal.
Horm Behav. 2010 Feb;57(2):192-7. doi: 10.1016/j.yhbeh.2009.10.013. Epub 2009 Nov 11.
Morphology and endocrinology were studied in two populations of the peacock blenny Salaria pavo, with different regimes of sexual selection imposed by differences in nest site availability. The peacock blenny is a small, sexually dimorphic benthic fish that presents exclusive paternal care of the clutch and inhabits rocky shores of the Mediterranean and adjacent Atlantic areas. In a population from the Gulf of Trieste (Northern Adriatic sea) inhabiting rocky shores where nest sites are abundant, male-male competition for nests is low, males court females and a low frequency of alternative reproductive tactics (small, parasitic female-mimicking sneaker males that change tactic into nest holders in subsequent breeding seasons) occurs. Conversely at Ria Formosa, a coastal lagoon in Southern Portugal, where nest sites are scarce and highly aggregated, male-male competition for nests is very high, there is sex-role reversal with female courtship and a high frequency of alternative reproductive tactics is observed. Concomitantly, at Ria Formosa nest holder males are larger and present more developed secondary sex characters and higher levels of 11KT than at the Gulf of Trieste. However, the gonads of nest holders and parasitic males were larger in the Gulf of Trieste population. Competition for nests at Ria Formosa seems to promote more developed secondary sex characters in nest site scarcity conditions, while competition for females at the Gulf of Trieste seems to be spurring sperm competition among males in populations where nest sites are more abundant. 11KT was thus associated with the development and expression of secondary sex characters in contrasting environments. These results exemplify how the modulation of behavioral plasticity and secondary sex characters by the social environment can be mediated by androgens.
形态学和内分泌学在两个孔雀斑鱼（Salaria pavo）种群中进行了研究，这些种群的性选择模式因巢穴可用性的差异而有所不同。孔雀斑鱼是一种小型、性二态的底栖鱼类，具有独特的雄性亲代育雏行为，栖息在地中海和相邻大西洋地区的岩石海岸。在来自的里雅斯特湾（亚得里亚海北部）的一个种群中，由于巢穴丰富，雄性间的巢穴竞争较低，雄性会向雌性求爱，而且替代生殖策略（体型较小、寄生的雌性模拟型 sneak 雄鱼，它们会在随后的繁殖季节改变策略成为巢穴持有者）的出现频率较低。相反，在葡萄牙南部的里奥福尔摩沙（Ria Formosa）沿海泻湖，由于巢穴稀缺且高度集中，雄性间的巢穴竞争非常激烈，出现了性角色反转，即雌性求爱，而且观察到替代生殖策略的出现频率较高。同时，在里奥福尔摩沙，巢穴持有者雄性的体型较大，具有更发达的第二性征和更高水平的 11KT，而在的里雅斯特湾则不是这样。然而，在的里雅斯特湾种群中，巢穴持有者和寄生雄性的性腺更大。在里奥福尔摩沙，巢穴竞争似乎促进了在巢穴稀缺条件下更发达的第二性征的发展，而在的里雅斯特湾，对雌性的竞争似乎刺激了在巢穴更丰富的种群中雄性之间的精子竞争。因此，11KT 与在对比环境中第二性征的发育和表达有关。这些结果说明了社会环境如何通过雄激素来调节行为可塑性和第二性征。
