植物&动物 | 生态&环境 | 大脑&行为 | 健康 | 技术 | 科学&政策 | 进化 | 古生物学 | 细胞 | 分子 | 基因&蛋白 | 遗传&发育 | 生物化学 | 生物物理 | 免疫 | 人物&事件 | 微生物学 |
当前位置: Science » 植物&动物 » Science:无形虾在试图逃跑时现形


标签:海葵虾 透明
摘要 : 小小的海葵虾(Ancylomenes pedersoni)把隐形的艺术几乎发挥到了极致:由于器官、血液和其他体液,我们人类大多数都不透明,然而它们却可以实现不可思议的、像个超人一样的半透明状态(上图)。


小小的海葵虾(Ancylomenes pedersoni)把隐形的艺术几乎发挥到了极致:由于器官、血液和其他体液,我们人类大多数都不透明,然而它们却可以实现不可思议的、像个超人一样的半透明状态(上图)。生理学家今天在综合与比较生物学协会年度会议上报告说,但在最需要的时候,它们可能会失去这些“超能力”。研究人员假设这些透明的动物总是清透如镜。但是研究团队中的一个研究生在收集海葵虾的时候注意到,有一只虾在经过几次临危逃脱之后身体变混浊了。它翻尾越多,身体就变得越不透明。然而,几个小时以后这种混浊就消失了。研究人员怀疑运动改变的血流可能是缘由,于是他们测量了进入虾的肌肉的血量。他们还利用电子显微镜来寻找透明和不透明肌肉之间的结构变化。他们发现,每当海葵虾做出突然的动作,血流就增加并导致光散射,从而让虾变得可见。研究人员描述这种差异为类似于积冰与雪的区别。这两种物质都是由冻结的水组成,并没有任何吸收光的色素。在冰块中,每一层都以完全相同的角度折射光线,使其能够轻易穿透。但是在雪人中,雪花之间的空气空间让光从许多不同的角度从不同的方向散射出去。入射光的所有颜色从雪人身上弹射开,使他看起来很洁白。海葵虾在休息时仅通过一根主要的血管将少量的血液输送到它的尾部。但是当它被吓到时,更多的血管张开,血液得以环绕肌纤维循环。血液和纤维散射光的方式不同,因此创造了“雪人的样子”。研究人员还发现了其它也会导致海葵虾身体变混浊的压力点,比如虾缸含盐量的改变。这一研究不仅揭示了海葵虾伪装策略的弱点,还解释了相对于让像眼睛透镜这样的单个组织变透明,让整个动物变透明这件事是多么大的挑战。


When they try to escape, these invisible shrimp become visible


The tiny anemone shrimp (Ancylomenes pedersoni) has nearly perfected the art of invisibility: Despite having the organs, blood, and other body fluids that make most of us opaque, they have achieved an uncanny, superherolike translucence (above). But they may lose these superhero powers when it matters most, report physiologists today at the annual meeting of the Society of Integrative and Comparative Biology. Researchers had assumed that transparent animals are always clear as glass. But while collecting anemone shrimp, a graduate student on the team noticed that after a few close calls, one shrimp’s body turned cloudy. The more tail flips it did, the more opaque it became. However, the cloudiness went away after a couple of hours. Suspecting that altered blood flow from exercise might be to blame, the researchers measured how much blood was getting into the shrimp’s muscles. They also used electron microscopy to look for structural changes between transparent and opaque muscle. They found that whenever the shrimp made sudden movements, blood flow increased and caused light to scatter, thus making the shrimp visible. Researchers described the difference as akin to that of packed ice and snow. Both substances are made of frozen water and lack any light-absorbing pigment. In ice cubes, each layer bends the light at exactly the same angle, allowing it to pass through easily. But in a snowman, air spaces between the snowflakes cause light to scatter in many different directions at many different angles. All the colors in the incoming light bounce off the snowman, making him look white. The shrimp, when resting, circulates just a small amount of blood to its tail through one major vessel. But when startled, it opens up more blood vessels, allowing blood to surround the muscle fibers. Differences between the way the blood and the fiber scatter light create the “snowman look.” The researchers also discovered that other stresses, such as altering salt levels in the shrimp tanks, cause them to become cloudy as well. Aside from exposing a weakness in the shrimp’s camouflage strategy, the work drives home how challenging it is to achieve transparency in whole animals, as opposed to single tissues like eye lenses.

来源: Science 浏览次数:0


RSS订阅 | 生物帮 | 粤ICP备11050685号-3 ©2011-2014 生物帮 Science  All rights reserved.