The Evolution of Cranial Forms in Anguilliform Fishes: Does Extreme Biting Promote or Constrain Morphological Diversity?

新的身体形式和行为模式的多样性是生物学的中心兴趣。在有机体设计中，可能引导或限制多样性的一个因素是特征的相关性：个体特征的多样性可能受到它们与其他特征的关联的限制。或者，一个特征或一组与功能相关的特征的巨大变化可能会对复杂系统的集成产生深远的影响，极大地影响系统设计和行为的结果。鱼的头骨是高度复杂的肌肉骨骼系统，用于关键的生存行为，如猎物捕获、猎物运输(吞咽)和呼吸。我们对硬骨鱼头骨设计的知识几乎完全来自于对吸食的研究，吸食是大多数鱼类捕获猎物、运输猎物和呼吸的主要方式。然而，咬人是一种替代的猎物捕获行为，已经在许多鱼类群体中进化，咬人谱系中形态和行为进化的进化动力学鲜为人知。这项研究将验证咬人的进化促进了最著名的咬鱼群体之一--鳗鱼及其盟友--的行为和形态多样化的观点。咬食猎物而不是使用吸力的鱼，以不同的方式修改了它们的下巴。在某些情况下，颌骨改造对一些通过咬人捕获猎物的鱼类的运输和呼吸复合体产生了级联效应。例如，海鳗是一个物种丰富的群体，属于一个更大的鱼类类群，被称为鳗形目，或真正的鳗鱼，它不依赖吸力来捕获或吞咽猎物。捕食者用牙齿咬住猎物来捕捉猎物。一旦猎物被捕获，蚂蚁就会将咽部的下巴伸进嘴里，抓住猎物，并将猎物送入食道。这种吞咽行为不同于任何其他鱼类运输行为，是在水环境中不使用吸力运输猎物的第一种替代方法。海里运输行为的这种新颖性为我们提供了一个机会来研究集成系统中的功能创新是如何产生的。这项研究将首次对咬伤对硬骨鱼头骨多样性的功能影响进行比较分析。这项工作还将提高我们对鳗鱼关系的理解，并将把化石信息与新收集的遗传数据结合起来，为该小组产生第一棵时间树。利用这棵树，我们建议识别鳗鱼头骨中特征关联和特征模块的广泛模式，以说明口腔颌骨的变化如何对用于猎物运输和呼吸的系统产生级联影响。首席调查员是第一次担任调查员，致力于招募和鼓励年轻科学家，特别是女性。这项资助的集体努力将为研究生和本科生提供各种解剖学技术方面的培训，同时也为这些发展中的科学家提供参加科学会议的机会。

The diversification of novel body forms and behavior patterns is of central interest in biology. One factor that may guide or constrain diversity in organismal design is the correlation of traits: individual trait diversity may be limited by their associations with other traits. Alternatively, a large change in one character or in a suite of functionally related traits may have far-reaching consequences on the integration of complex systems, greatly affecting the outcome of system design and behavior. Fish skulls are highly complex musculoskeletal systems that are used for critical survival behaviors such as prey capture, prey transport (swallowing), and respiration. Our knowledge of skull design in teleost fishes is derived almost entirely from studies of suction feeding, the dominant mode of prey capture, prey transport, and respiration for the majority of fishes. However, biting is an alternative prey capture behavior that has evolved across many fish groups and the evolutionary dynamics of morphological and behavioral evolution in biting lineages is poorly understood. This study will test the idea that the evolution of biting has promoted diversification in behavior and morphology in one of the most prominent groups of biting fishes: eels and their allies. Fishes that bite their prey rather than use suction, have modified their jaws in diverse ways. In some cases, jaw modification has had cascading effects on the transport and respiratory complex for some of these fish species that capture their prey by biting. For example, moray eels, a species rich group belonging to a larger group of fishes known as the anguilliforms, or true eels, do not rely on suction for capturing or swallowing their prey. Morays capture their prey by sinking their teeth into them. Once the prey is captured, morays protract their pharyngeal jaws, a second set of jaws in their throat, into their mouths to grab the prey item and transport the prey into their esophagus. This swallowing behavior is unlike any other fish transport behavior and presents the first alternative method for transporting prey without the use of suction in the aquatic environment. This novelty in moray transport behavior provides an opportunity to examine how functional innovations in integrated systems arise. This study will be the first comparative analysis on the functional implications of biting on teleost skull diversity. This work will also improve our understanding of eel relationships and will integrate fossil information with newly collected genetic data to produce the first time tree for the group. With this tree we propose to identify broad patterns of trait associations and trait modularity in the skull of eels to illustrate how a change in the oral jaws has had cascading effects on systems used for prey transport, and respiration. The principal investigator is a first time investigator who is committed to recruiting and encouraging young scientists, especially women. The collective efforts of this grant will provide training for graduate students and undergraduates in a variety of anatomical techniques, while also providing opportunities for these developing scientists to attend scientific meetings.