Cortesi Fabio, Musilová Zuzana, Stieb Sara M, Hart Nathan S, Siebeck Ulrike E, Cheney Karen L, Salzburger Walter, Marshall N Justin
Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia Zoological Institute, University of Basel, Basel 4051, Switzerland
Zoological Institute, University of Basel, Basel 4051, Switzerland Department of Zoology, Charles University in Prague, Prague 128 44, Czech Republic.
J Exp Biol. 2016 Aug 15;219(Pt 16):2545-58. doi: 10.1242/jeb.139501. Epub 2016 Jun 15.
Animals often change their habitat throughout ontogeny; yet, the triggers for habitat transitions and how these correlate with developmental changes - e.g. physiological, morphological and behavioural - remain largely unknown. Here, we investigated how ontogenetic changes in body coloration and of the visual system relate to habitat transitions in a coral reef fish. Adult dusky dottybacks, Pseudochromis fuscus, are aggressive mimics that change colour to imitate various fishes in their surroundings; however, little is known about the early life stages of this fish. Using a developmental time series in combination with the examination of wild-caught specimens, we revealed that dottybacks change colour twice during development: (i) nearly translucent cryptic pelagic larvae change to a grey camouflage coloration when settling on coral reefs; and (ii) juveniles change to mimic yellow- or brown-coloured fishes when reaching a size capable of consuming juvenile fish prey. Moreover, microspectrophotometric (MSP) and quantitative real-time PCR (qRT-PCR) experiments show developmental changes of the dottyback visual system, including the use of a novel adult-specific visual gene (RH2 opsin). This gene is likely to be co-expressed with other visual pigments to form broad spectral sensitivities that cover the medium-wavelength part of the visible spectrum. Surprisingly, the visual modifications precede changes in habitat and colour, possibly because dottybacks need to first acquire the appropriate visual performance before transitioning into novel life stages.
动物在个体发育过程中常常会改变其栖息地；然而，栖息地转变的触发因素以及这些因素与发育变化（如生理、形态和行为方面的变化）之间的关联在很大程度上仍不为人知。在此，我们研究了一种珊瑚礁鱼类体色和视觉系统的个体发育变化与栖息地转变之间的关系。成年暗色宅泥鱼（Pseudochromis fuscus）是具有攻击性的拟态者，它们会改变颜色以模仿周围环境中的各种鱼类；然而，对于这种鱼的早期生活阶段却知之甚少。通过结合发育时间序列以及对野生捕获标本的检查，我们发现宅泥鱼在发育过程中会经历两次颜色变化：（i）近乎半透明的隐蔽浮游幼体在定居于珊瑚礁时会转变为灰色的保护色；（ii）幼鱼在达到能够捕食幼鱼猎物的大小时会转变为模仿黄色或棕色鱼类的颜色。此外，显微分光光度法（MSP）和定量实时聚合酶链反应（qRT-PCR）实验显示了宅泥鱼视觉系统的发育变化，包括一种新的成年特异性视觉基因（RH2视蛋白）的使用。该基因可能与其他视觉色素共同表达，以形成覆盖可见光谱中波长部分的广泛光谱敏感性。令人惊讶的是，视觉方面的变化先于栖息地和颜色的变化，这可能是因为宅泥鱼在过渡到新的生活阶段之前需要首先获得适当的视觉能力。
