Shelford Vivarium, 606 E. Healey St., Champaign, IL 61820, U.S.A.
J Fish Biol. 2014 May;84(5):1389-400. doi: 10.1111/jfb.12364. Epub 2014 Apr 11.
Robust reproductive isolation was found between the rainbow darter Etheostoma caeruleum and the orangethroat darter Etheostoma spectabile, as more offspring were produced when conspecific males and females were crossed as compared with heterospecific crosses. Furthermore, fewer eggs resulted from heterospecific crosses involving sympatric E. spectabile females than those using allopatric E. spectabile females, while a similar pattern was not observed in heterospecific crosses using E. caeruleum females. These results suggest that reinforcement, i.e. selection for pre-zygotic reproductive barriers driven by reduced hybrid fitness, may have contributed to the evolution and maintenance of reproductive barriers between these potentially hybridizing species in sympatry.
在彩虹鮈和橙喉鮈之间发现了强大的生殖隔离，因为与异源杂交相比，同种的雌雄个体交配产生的后代更多。此外，与使用异地橙喉鮈雌鱼的杂交相比，来自涉及同域橙喉鮈雌鱼的异源杂交的卵子更少，而在使用彩虹鮈雌鱼的异源杂交中没有观察到类似的模式。这些结果表明，强化作用，即由杂种适合度降低驱动的合子前生殖障碍的选择，可能促成了这些在同域中可能杂交的物种之间生殖障碍的进化和维持。
