Sides and eyes: studies on laterality in anuran larvae

侧面和眼睛：无尾幼虫侧向性的研究

• 批准号: 8194-2007
• 负责人: Wassersug, Richard
• 金额: $ 3.09万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=361280
• 关键词: Sides; eyes; studies; laterality; anuran

Although they don't have hands, tadpoles can nevertheless have handedness. For instance, tadpoles of most species typically turn about twice as often to their left than their right side when startled. Even more curious, tadpoles of many species (but not all) prefer to view themselves in mirrors with their left eye rather than their right. With NSERC support I plan to survey such "lateralized" behaviors from tadpoles of as many families and genera of frogs as possible. My overall goal is to understand the evolution of lateralized behaviors in these organisms.  There is circumstantial evidence that turning bias in tadpoles is linked to asymmetry in the size of certain cells in their hindbrains. In order to elucidate this behavioural-neural link, I will examine the size of those cells in species with strongly lateralized behaviors. I will then test the hypothesis that handedness in tadpoles correlates with both the evolutionary relationships of the frogs and asymmetries in their brains.  There are some recent data suggesting that predation risk influenced tadpole turning bias. I thus plan to investigate this in several species by recording tadpoles' turning biases while caged predators, such as fish, are nearby.  Lastly, I have suggested that tadpoles might interpret their own image in a mirror as another tadpole and respond to their images as if they were crowded by other tadpoles. With NSERC support, I wish to test the hypothesis that different species will grow at different rates when raised in aquaria with mirrored walls depending on their propensity to live in dense groups (i.e., to school).      Collectively this research should advance our understanding of the adaptive significance and evolution of lateralized behaviours in anurans and in other animals as well.

虽然蝌蚪没有手，但它们却有用手习惯。例如，大多数物种的蝌蚪在受到惊吓时，通常向左侧转动的次数是右侧的两倍。更奇怪的是，许多种类的蝌蚪（但不是全部）更喜欢用左眼而不是右眼在镜子中观察自己。在NSERC的支持下，我计划调查尽可能多的青蛙科属的蝌蚪的这种“偏侧”行为。我的总体目标是了解这些生物体中偏侧化行为的进化，有间接证据表明，蝌蚪的转向偏好与它们后脑中某些细胞大小的不对称有关。为了阐明这种行为-神经联系，我将研究具有强烈侧化行为的物种中这些细胞的大小。然后，我将检验这一假设，即蝌蚪的惯用手与青蛙的进化关系和它们大脑中的不对称性相关。最近有一些数据表明，捕食风险影响了蝌蚪的转向偏好。因此，我计划在几个物种中研究这一点，记录蝌蚪在笼子里的捕食者（如鱼）附近时的转向偏差。最后，我提出，蝌蚪可能会将自己在镜子中的形象解释为另一只蝌蚪，并对他们的形象做出反应，就好像他们被其他蝌蚪挤在一起一样。在NSERC的支持下，我希望测试这样一个假设，即不同的物种在有镜子墙的水族馆中生长的速度不同，这取决于它们生活在密集群体中的倾向（即，上学）。 总的来说，这项研究应该促进我们对无尾类和其他动物侧化行为的适应意义和进化的理解。