澳大利亚科学家近期研究发现鲨鱼很可能是色盲，人们可以根据这个特点研制不会误捕鲨鱼的渔具，以及能减少遭鲨鱼攻击的服装。
西澳大利亚大学与昆士兰大学的研究人员检测了17种澳大利亚周边不同种类的鲨鱼的视网膜，发现这些动物只有一种能辨识颜色的视锥细胞。人眼有三种视锥细胞，分别能看到蓝色、绿色与红色的光，这样人们就能识别不同颜色的物体。
项目负责人内森 哈特博士称，这项调查结果可以帮助人类改进一些防止被鲨鱼袭击的措施，也有助于研制避免误捕鲨鱼的渔具。 “我们的研究显示，鲨鱼在探测目标时，如果目标与其周遭环境的对比反差较大，就比较容易被鲨鱼探测到，而不是我们传统认为的，色彩艳丽的物体对鲨鱼比较显眼，”他进一步解释说，“我们可以设计一些对鲨鱼而言与周围环境视觉对比不是很强烈的泳装和冲浪用具，以减少对它们的吸引力。”
人类视网膜布满了能感应光线强弱的杆状细胞和辨识颜色的视锥细胞。杆状细胞在光线昏暗的环境比视锥细胞的功能发挥好，而在所有17种鲨鱼身上找到最常见的就是杆状细胞。
科学家在其中10种鲨鱼身上根本找不到视锥细胞，而另外7种鲨鱼只有一种仅对一个波段的光敏感的视锥细胞，也就是说它们只能看到一种颜色。因此，如果鲨鱼的视网膜像研究人员所称无法辨别不同的颜色，那它们可能就是完全的色盲。（生物谷Bioon.com）
生物谷推荐原文出处：
Naturwissenschaften, 2011; DOI: 10.1007/s00114-010-0758-8
Microspectrophotometric evidence for cone monochromacy in sharks
Nathan Scott Hart, Susan Michelle Theiss, Blake Kristin Harahush and Shaun Patrick Collin
Abstract
Sharks are apex predators, and their evolutionary success is in part due to an impressive array of sensory systems, including vision. The eyes of sharks are well developed and function over a wide range of light levels. However, whilst close relatives of the sharks—the rays and chimaeras—are known to have the potential for colour vision, an evolutionary trait thought to provide distinct survival advantages, evidence for colour vision in sharks remains equivocal. Using single-receptor microspectrophotometry, we measured the absorbance spectra of visual pigments located in the retinal photoreceptors of 17 species of shark. We show that, while the spectral tuning of the rod (wavelength of maximum absorbance, λmax 484–518 nm) and cone (λmax 532–561 nm) visual pigments varies between species, each shark has only a single long-wavelength-sensitive cone type. This suggests that sharks may be cone monochromats and, therefore, potentially colour blind. Whilst cone monochromacy on land is rare, it may be a common strategy in the marine environment: many aquatic mammals (whales, dolphins and seals) also possess only a single, green-sensitive cone type. It appears that both sharks and marine mammals may have arrived at the same visual design by convergent evolution. The spectral tuning of the rod and cone pigments of sharks is also discussed in relation to their visual ecology.
Keywords Shark – Colour vision – Microspectrophotometry – Cone – Visual pigment
