Pampoulie Christophe, Gíslason Davíð, Ólafsdóttir Guðbjörg, Chosson Valérie, Halldórsson Sverrir Daníel, Mariani Stefano, Elvarsson Bjarki Þ, Rasmussen Marianne H, Iversen Maria R, Daníelsdóttir Anna Kristín, Víkingsson Gísli A
Marine and Freshwater Research Institute Hafnarfjörður Iceland.
Matís ohf. Reykjavík Iceland.
Evol Appl. 2020 Aug 28;14(2):314-321. doi: 10.1111/eva.13091. eCollection 2021 Feb.
Biodiversity in the oceans has dramatically declined since the beginning of the industrial era, with accelerated loss of marine biodiversity impairing the ocean's capacity to maintain vital ecosystem services. A few organisms epitomize the damaging and long-lasting effects of anthropogenic exploitation: Some whale species, for instance, were brought to the brink of extinction, with their population sizes reduced to such low levels that may have caused a significant disruption to their reproductive dynamics and facilitated hybridization events. The incidence of hybridization is nevertheless believed to be rare, and very little information exists on its directionality. Here, using genetic markers, we show that all but one whale hybrid sample collected in Icelandic waters originated from the successful mating of male fin whale and female blue whale, thus suggesting unidirectional hybridization. We also demonstrate for the first time the existence of a second-generation adult (male) hybrid resulting from a backcross between a female hybrid and a pure male fin whale. The incidence of hybridization events between fin and blue whales is likely underestimated and the observed unidirectional hybridization (for F1 and F2 hybrids) is likely to induce a reproductive loss in blue whale, which may represent an additional challenge to its recovery in the Atlantic Ocean compared to other rorquals.
自工业时代开始以来，海洋生物多样性急剧下降，海洋生物多样性的加速丧失损害了海洋维持重要生态系统服务的能力。一些生物体现了人为开发造成的破坏性和长期影响：例如，一些鲸鱼物种濒临灭绝，其种群数量降至极低水平，这可能对它们的繁殖动态造成了重大干扰，并促成了杂交事件。然而，杂交的发生率被认为很低，关于其方向性的信息也非常少。在这里，我们使用基因标记表明，在冰岛海域收集的所有鲸鱼杂交样本中，除了一个之外，都源自雄性长须鲸与雌性蓝鲸的成功交配，因此表明存在单向杂交。我们还首次证明了存在第二代成年（雄性）杂交种，它是由雌性杂交种与纯种雄性长须鲸回交产生的。长须鲸和蓝鲸之间杂交事件的发生率可能被低估了，而且观察到的单向杂交（对于F1和F2杂交种）可能会导致蓝鲸的繁殖损失，这可能是其在大西洋恢复过程中面临的一个额外挑战，与其他须鲸相比情况更为严峻。
