The ontogeny of bite-force performance in American alligator (Alligator mississippiensis)
The ontogeny of bite-force performance in American alligator (Alligator mississippiensis)
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DOI：
10.1017/s0952836903003819
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发表时间：
2003-07-01
影响因子：
2
通讯作者：
Vliet, KA
中科院分区：
文献类型：
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作者：
Erickson, GM;Lappin, AK;Vliet, KA
美国短吻鳄密西西比鳄在发育过程中经历了形态和生态的重大转变。这些变化包括身体质量的数千倍变化，鼻子和牙齿比例的改变，以及饮食从小而精致的食物转变为越来越大，更强壮的猎物。这些解剖形式的变化如何有助于实际的身体表现和利基使用在很大程度上是未知的。本研究对41个A. Mississipiensis，使用一系列精确的力传感器在整个个体发育（孵化-老年人）中进行。确定了该性能指标相对于颅骨和全身测量的比例。咬力生产在整个发展过程中进行了对比与营养生态学的个体发育变化。然后分析了这一业绩指标对这些变化的影响。结果显示，咬合力的范围为800倍（12-9452 N），其值与体型的增加呈正相关。通过个体发育的咬合力的缩放表现出积极的异速生长相对于体重，头长，颌长，口鼻长度和总长度。这些模式可能归因于个体骨骼元素（和相关肌肉组织）的异速生长，和/或在发育过程中颅骨和颌骨的进行性融合和骨化。整个个体发育过程中力量增加的总体模式并不与饮食的重大变化相关。值得注意的是，成年A.密西西比鳄是所有现存动物中最高的，也是大型鳄鱼的第一种。此外，这些数据提供了第一个文件咬合力如何在爬行动物个体发育过程中的变化。通过连接这些动物丰富的形态学和生态学数据库，这项研究打开了一扇大门，全面了解在A。密西西比河。此外，它提供了标准化的比较研究鳄鱼，爬行动物，或其他有颚类脊椎动物之间的摄食基础。
American alligators Alligator mississippiensis undergo major transformations in morphology and ecology during development. These include several thousand-fold changes in body mass, modified snout and dental proportions, and shifts in diet from small, delicate foodstuffs to the inclusion of increasingly larger, more robust prey. How these changes in anatomical form contribute to actual physical performance and niche use is largely unknown. In the present study, bite-force measurements for 41 specimens of A. mississipiensis, were made throughout ontogeny (hatchling-older adults) using a series of precision force transducers. How this performance indicator scaled with respect to cranial and whole-body measurements was determined. Bite-force production throughout development was contrasted with ontogenetic changes in trophic ecology. The influences of this performance measure on these changes were then analysed. The results showed a 800-fold range (12-9452 N) of bite forces with values positively correlating with increases in body size. Scaling of biting forces through ontogeny showed positive allometry with respect to body mass, head length, jaw length, snout-vent length and total length. These patterns may be attributable to allometric growth of individual skeletal elements (and associated musculature), and/or progressive fusion and ossification of skull and jawbones during development. The overall pattern of force increase throughout ontogeny did not vary in association with major shifts in diet. Notably, the bite-force values for adult A. mississippiensis are the highest measured for any living animal and represent the first measures for a large crocodilian. Additionally, these data provide the first documentation of how bite force changes during ontogeny in a reptile. By bridging the rich morphological and ecological databases for these animals, this study opens the door to a comprehensive understanding of feeding in A. mississippiensis. Furthermore, it provides groundwork for standardized comparative studies of feeding among crocodilian, reptilian, or other gnathostome vertebrates.