SGER: UV Communication in Swordtails

许多动物所经历的环境是我们所不了解的。蝙蝠使用回声定位，一些昆虫感知基底振动。我们最近发现，一种叫侏儒剑尾鱼的鱼能在紫外线下交流——我们的皮肤对紫外线敏感，但眼睛对紫外线不敏感。雄性剑尾鱼的剑长在尾鳍之外。我们之前的研究无意中排除了紫外线，从未能证明雌性更喜欢有剑的雄性而不是没有剑的雄性。最近我们发现剑会反射紫外线，当在含有紫外线的光线下（例如阳光）测试时，雌性确实更喜欢带剑的雄性。因此，紫外线在涉及配偶选择的交流系统中起着关键作用。我们还发现剑尾鱼的主要捕食者，墨西哥四环鱼，在紫外线下是看不到的。因此，雄性可以通过在剑上增加紫外线反射来增加对雌性的明显性，而不是对捕食者。在拟议的研究中，我们将确定这些鱼类的紫外线通信系统有多普遍，紫外线的变化是否影响动物的求爱时间，视觉系统对紫外线的敏感程度，紫外线的存在是否影响捕食者的狩猎成功，剑尾鱼是否利用紫外线完成其他任务，例如定位自己的猎物。这些研究有望让我们深入了解这些动物以前不为人知的感官世界。

Many animals experience parts of the environment to which we are not privy. Bats use echolocation, some insects sense substrate vibrations. We recently found that a fish, the pygmy swordtail, communicates in the ultraviolet (UV)-- light to which our skin but not ours eyes are sensitive. Male swordtails have a sword that extends beyond the tail fin. Our previous studies, which inadvertently excluded UV, were never able to show that females preferred males with swords to those without swords. Recently we discovered that the sword reflects UV, and that when tested under light containing UV (e.g. sunlight) females do indeed prefer males with swords. Thus UV plays a critical role in the communication system involved in mate choice. We also found that the swordtail's major predator, the Mexican tetra, does not see in the UV. Thus males can increase their conspicuousness to females but not predators by adding UV reflectance to the sword.In the proposed study we will determine how general the UV communication system is in these types of fishes, if variation in the presence of UV influence when the animal's court, how sensitive the visual system is to UV, if the presence of UV does not influence the predator's hunting success, and if the swordtails use UV for other tasks, such as locating their own prey. These studies promise to give us insights into a sensory world of these animals that was previously unknown.