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

鳗鱼颅骨形态的进化：极端咬合会促进还是限制形态多样性？

• 批准号: 0819009
• 负责人: Rita Mehta
• 金额: $ 34.46万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-15 至 2010-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0819009&HistoricalAwards=false
• 关键词: Evolution; Cranial; Forms; Anguilliform; Fishes

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.

新的身体形式和行为模式的多样化是生物学的中心兴趣。在生物设计中，一个可能指导或限制多样性的因素是性状的相关性：个体性状的多样性可能受到它们与其他性状的关联的限制。另一方面，一个角色或一组功能相关特征的巨大变化可能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了解几乎完全来自于对吸力进食的研究，吸力进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，咬是一种可选择的猎物捕获行为，已经在许多鱼类群体中进化，咬系的形态和行为进化动力学尚不清楚。这项研究将检验这样一种观点，即咬人的进化促进了最突出的咬鱼群体之一的行为和形态的多样化：鳗鱼和它们的盟友。那些用咬而不是吸的方式来捕食的鱼，以不同的方式改变了它们的下颚。在某些情况下，下颌的改变对一些通过咬来捕获猎物的鱼类的运输和呼吸系统产生了级联效应。例如，海鳗，一个物种丰富的群体，属于一个更大的鱼类群体，被称为鳗，或真正的鳗鱼，不依赖于吸力捕捉或吞咽猎物。海鳗用牙齿咬住猎物来捕捉猎物。一旦猎物被捕获，海鳗就会把它们的咽颌（喉咙里的第二副颌）伸到嘴里，抓住猎物并把猎物运送到食道里。这种吞咽行为不同于任何其他鱼类运输行为，并提出了在水生环境中不使用吸力运输猎物的第一种替代方法。海洋运输行为的这种新颖性为研究集成系统的功能创新如何产生提供了机会。本研究将首次比较分析咬伤对硬骨鱼颅骨多样性的功能影响。这项工作还将提高我们对鳗鱼关系的理解，并将化石信息与新收集的遗传数据相结合，为该群体产生第一个时间树。通过这棵树，我们提出在鳗鱼头骨中识别特征关联和特征模块化的广泛模式，以说明口腔颌部的变化如何对用于猎物运输和呼吸的系统产生级联效应。首席研究员为初任研究员，致力于招募和鼓励年轻科学家，特别是女性科学家。这项资助的共同努力将为研究生和本科生提供各种解剖技术的培训，同时也为这些发展中的科学家提供参加科学会议的机会。