Valero Alejandra, Macías Garcia Constantino, Magurran Anne E
Gatty Marine Laboratory, University of St Andrews, St Andrews, Fife KY16 8LB, UK.
Biol Lett. 2008 Apr 23;4(2):149-52. doi: 10.1098/rsbl.2007.0604.
Persistent courtship by male Trinidadian guppies (Poecilia reticulata) is costly for conspecific females. Since male guppies are known to attempt matings with other poeciliid females, we asked whether persistent courtship is also directed towards morphologically similar but phylogenetically distant females encountered following invasion. Skiffia bilineata is one of several endangered viviparous goodeids from Central México, whose remaining habitats are increasingly shared with invasive guppies. Experiments in which guppy sex ratios were manipulated to vary the proportion of heterospecific to conspecific females showed that male guppies courted and attempted forced copulations with S. bilineata females even when females of their own species were in excess. This behaviour places an additional, and previously unrecognized, burden on a group of endemic Mexican fishes already in risk of extinction.
特立尼达孔雀鱼（Poecilia reticulata）雄鱼的持续求偶行为对同种雌鱼来说代价高昂。由于已知雄孔雀鱼会试图与其他花鳉科雌鱼交配，我们便探究持续求偶行为是否也针对入侵后遇到的形态相似但系统发育关系较远的雌鱼。双线斯基夫鳉（Skiffia bilineata）是墨西哥中部几种濒危胎生硬骨鳉之一，其剩余栖息地与入侵的孔雀鱼的重叠日益增多。通过操控孔雀鱼的性别比例来改变异种雌鱼与同种雌鱼的比例进行实验，结果表明，即使同种雌鱼数量过剩，雄孔雀鱼仍会向双线斯基夫鳉雌鱼求偶并试图强行交配。这种行为给一群本就面临灭绝风险的墨西哥特有鱼类带来了额外的、此前未被认识到的负担。
