Institute of Ecology and Evolution, University of Bern, Bern, Switzerland.
Sci Rep. 2020 Jun 26;10(1):10407. doi: 10.1038/s41598-020-67294-x.
Unlike eusocial systems, which are characterized by reproductive division of labour, cooperative breeders were predicted not to exhibit any reproductive specialization early in life. Nevertheless, also cooperative breeders face a major life-history decision between dispersal and independent breeding vs staying as helper on the natal territory, which might affect their reproductive strategies. In the cooperatively-breeding cichlid Neolamprologus pulcher early-life social and predator experiences induce two behavioural types differing in later-life social and dispersal behaviour. We performed a long-term breeding experiment to test whether the two early-life behavioural types differ in their reproductive investment. We found that the early-dispersing type laid fewer and smaller eggs, and thus invested overall less in reproduction, compared to the philopatric type. Thus N. pulcher had specialised already shortly after birth for a dispersal and reproductive strategy, which is in sharp contrast to the proposition that reproductively totipotent cooperative breeders should avoid reproductive specialization before adulthood.
与以生殖分工为特征的真社会性系统不同,合作繁殖者在生命早期预计不会表现出任何生殖专门化。然而,合作繁殖者也面临着在扩散和独立繁殖与留在出生地作为帮手之间做出重大的生活史决策,这可能会影响他们的繁殖策略。在合作繁殖的慈鲷 Neolamprologus pulcher 中,早期的社会和捕食者经历会诱导出两种行为类型,它们在后期的社会和扩散行为上有所不同。我们进行了一项长期的繁殖实验,以测试这两种早期行为类型在生殖投资上是否存在差异。我们发现,与恋地型相比,早期扩散型产卵更少、更小,因此整体生殖投资较少。因此,N. pulcher 出生后不久就专门为一种扩散和生殖策略进行了专门化,这与繁殖全能的合作繁殖者在成年前应避免生殖专门化的观点形成鲜明对比。