澳大利亞科學(xué)家近期研究發(fā)現(xiàn)鯊魚很可能是色盲，人們可以根據(jù)這個(gè)特點(diǎn)研制不會(huì)誤捕鯊魚的漁具,，以及能減少遭鯊魚攻擊的服裝,。
西澳大利亞大學(xué)與昆士蘭大學(xué)的研究人員檢測(cè)了17種澳大利亞周邊不同種類的鯊魚的視網(wǎng)膜,，發(fā)現(xiàn)這些動(dòng)物只有一種能辨識(shí)顏色的視錐細(xì)胞,。人眼有三種視錐細(xì)胞,，分別能看到藍(lán)色、綠色與紅色的光,，這樣人們就能識(shí)別不同顏色的物體,。
項(xiàng)目負(fù)責(zé)人內(nèi)森 哈特博士稱，這項(xiàng)調(diào)查結(jié)果可以幫助人類改進(jìn)一些防止被鯊魚襲擊的措施,，也有助于研制避免誤捕鯊魚的漁具,。 “我們的研究顯示，鯊魚在探測(cè)目標(biāo)時(shí),，如果目標(biāo)與其周遭環(huán)境的對(duì)比反差較大,，就比較容易被鯊魚探測(cè)到，而不是我們傳統(tǒng)認(rèn)為的,，色彩艷麗的物體對(duì)鯊魚比較顯眼,，”他進(jìn)一步解釋說，“我們可以設(shè)計(jì)一些對(duì)鯊魚而言與周圍環(huán)境視覺對(duì)比不是很強(qiáng)烈的泳裝和沖浪用具,，以減少對(duì)它們的吸引力,。”
人類視網(wǎng)膜布滿了能感應(yīng)光線強(qiáng)弱的桿狀細(xì)胞和辨識(shí)顏色的視錐細(xì)胞。桿狀細(xì)胞在光線昏暗的環(huán)境比視錐細(xì)胞的功能發(fā)揮好,，而在所有17種鯊魚身上找到最常見的就是桿狀細(xì)胞,。
科學(xué)家在其中10種鯊魚身上根本找不到視錐細(xì)胞，而另外7種鯊魚只有一種僅對(duì)一個(gè)波段的光敏感的視錐細(xì)胞,，也就是說它們只能看到一種顏色,。因此，如果鯊魚的視網(wǎng)膜像研究人員所稱無法辨別不同的顏色,，那它們可能就是完全的色盲,。（生物谷Bioon.com）
生物谷推薦原文出處：
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
