Advanced optics in a jellyfish eye
Advanced optics in a jellyfish eye
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DOI：
10.1038/nature03484
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发表时间：
2005-05-12
期刊：
影响因子：
64.8
通讯作者：
Garm, A
中科院分区：
文献类型：
--
作者：
Nilsson, DE;Gislén, L;Garm, A
立方体水母，或盒子水母，不同于所有其他蛇形动物，其活跃的类似鱼的行为和复杂的感官器官(1，2)。这种动物的四边各有一根明显的感觉棒(纹状体)，它已经进化成一群奇怪的不同眼睛(3)。长久以来，人们一直都知道，每个纹状体上的两只眼睛与高等动物的眼睛相似，但这些眼睛的功能和表现仍然未知[4]。在这里，我们展示了盒子水母透镜包含一个微调的折射率梯度，产生几乎无像差成像。这表明，即使是简单的动物，也已经能够进化出复杂的视觉光学，而以前人们只知道这种视觉光学是由少数高级的双侧门进化而来的。然而，视网膜的位置与清晰的图像不一致，导致单个光感受器的感受野非常广泛和复杂。我们认为，这可能对服务于单一视觉任务的眼睛有用。这些发现表明，复杂感受野的定制可能是动物晶状体进化的原始驱动力之一。
Cubozoans, or box jellyfish, differ from all other cnidarians by an active fish-like behaviour and an elaborate sensory apparatus(1,2). Each of the four sides of the animal carries a conspicuous sensory club ( the rhopalium), which has evolved into a bizarre cluster of different eyes(3). Two of the eyes on each rhopalium have long been known to resemble eyes of higher animals, but the function and performance of these eyes have remained unknown(4). Here we show that box-jellyfish lenses contain a finely tuned refractive index gradient producing nearly aberration-free imaging. This demonstrates that even simple animals have been able to evolve the sophisticated visual optics previously known only from a few advanced bilaterian phyla. However, the position of the retina does not coincide with the sharp image, leading to very wide and complex receptive fields in individual photoreceptors. We argue that this may be useful in eyes serving a single visual task. The findings indicate that tailoring of complex receptive fields might have been one of the original driving forces in the evolution of animal lenses.