Department of Educational Work, University of Borås, Borås, Sweden.
The Linnaeus Centre for Marine Evolutionary Biology, University of Gothenburg, Gothenburg, Sweden.
J Evol Biol. 2024 Jan 29;37(1):51-61. doi: 10.1093/jeb/voad006.
Work on the Lake Victoria cichlids Pundamilia nyererei (red dorsum males, deeper water), Pundamilia pundamilia (blue males, shallower water) and related species pairs has provided insights into processes of speciation. Here, we investigate the female mating behaviour of 5 Pundamilia species and 4 of their F1 hybrids through mate choice trials and paternity testing. Complete assortative mating was observed among all sympatric species. Parapatric species with similar depth habitat distributions interbred whereas other parapatric and allopatric species showed complete assortative mating. F1 hybrids mated exclusively with species accepted by females of the parental species. The existence of complete assortative mating among some currently allopatric species suggests that pre-existing mating barriers could be sufficient to explain current patterns of co-existence, although, of course, many other factors may be involved. Regardless of the mechanism, mating preferences may influence species distribution in potentially hybridizing taxa, such as in the adaptive radiation of cichlid fish. We suggest that this at least partly explains why some species fail to establish breeding populations in locations where they are occasionally recorded. Our results support the notion that the mating preferences of potentially cross-breeding species ought to be included in coexistence theory.
对维多利亚湖慈鲷属鱼类（红背雄鱼，生活在深水区）、Pundamilia pundamilia（蓝面雄鱼，生活在浅水区）及其相关种对的研究为物种形成过程提供了深入了解。在这里，我们通过配偶选择试验和亲子鉴定研究了 5 种 Pundamilia 物种及其 4 种 F1 杂种的雌性交配行为。所有同域物种均观察到完全的选择性交配。具有相似水深生境分布的并系物种进行杂交，而其他的并系和异域物种则表现出完全的选择性交配。F1 杂种仅与雌性亲本物种接受的物种交配。一些目前异域分布的物种之间存在完全的选择性交配，这表明预先存在的交配障碍可能足以解释当前的共存模式，尽管当然还有许多其他因素可能涉及其中。无论机制如何，交配偏好可能会影响潜在杂交类群的物种分布，例如慈鲷鱼类的适应性辐射。我们认为，这至少部分解释了为什么有些物种在它们偶尔被记录到的地方未能建立繁殖种群。我们的研究结果支持这样一种观点，即应将潜在杂交物种的交配偏好纳入共存理论。
