The effects of substrate and vertebral number on locomotion in the garter snake Thamnophis elegans
The effects of substrate and vertebral number on locomotion in the garter snake Thamnophis elegans
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DOI：
10.1046/j.1365-2435.1997.00077.x
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发表时间：
1997-04-01
影响因子：
5.2
通讯作者：
Glatstone, J
中科院分区：
文献类型：
--
作者：
Kelley, KC;Arnold, SJ;Glatstone, J
1.无肢脊椎动物的运动能力取决于个体活动的底物，并可能导致不同栖息地的脊椎数的选择。为了评估推点密度对蛇活动的影响，在加利福尼亚的两个地点(沿海和内陆)对植被和其他潜在推点的密度进行了量化，其中同种蛇的脊椎数差异很大(分别为230和256个椎骨；Arnold，1988)。沿海站点的推点密度显著高于内陆站点。五种实验推点密度落在推点密度的自然范围内，用于幼蛇运动的实验室试验。推力点的密度显著影响爬行速度和头尾距离(HTD)，HTD是间接测量侧向弯曲的指标。在中等推点密度下获得了最快的速度。当蛇通过最低推点密度时，出现最短的HTD。性别、椎体总数和全长对HTD有显著影响，与推点密度无关。椎骨相对较多的蛇有较短的HTD，这表明它们比椎骨较少的蛇能够获得更大的侧弯。沿海和内陆人群在迁徙过程中的HTD差异不大。身体和尾椎的数量在不同推点密度下对速度有显著影响。一般来说，蛇的身体脊椎比脊椎少的要慢，而尾椎多的蛇比尾椎少的快。全长较大的蛇在所有密度下都跑得更快。在所有推点密度下，沿海蛇的爬行速度都快于内陆蛇。
1. Locomotor performance of limbless vertebrates depends on the substrate through which individuals move and may result in selection on vertebral number in different habitats. To evaluate the effect of push-point density on snake locomotion, the density of vegetation and other potential push-points was quantified at two sites in California (coastal and inland), where conspecific snakes differed greatly in vertebral number (230 and 256 average total vertebrae, respectively; Arnold 1988). The coastal site had significantly higher push-point densities than the inland site.2. Five experimental push-point densities that fell within the natural range of push-point densities were employed in laboratory trials of juvenile snake locomotion. Density of push-points significantly affected both crawling speed and head-to-tail distance (HTD), an indirect measure of lateral bending. The fastest speed was achieved at an intermediate push-point density. The shortest HTD occurred when snakes moved through the lowest push-point density.3. Sex, total number of vertebrae and total length significantly affected HTD, regardless of push-point density. Snakes with relatively more vertebrae had a shorter HTD, suggesting they were able to achieve greater lateral bending than snakes with fewer vertebrae. Coastal and inland populations did not differ in HTD during locomotion.4. Numbers of body and tail vertebrae significantly influenced speed at different push-point densities. In general, snakes with more: body vertebrae were slower than those with fewer, while snakes with more tail vertebrae were faster than those with fewer. Snakes of greater total length were faster at all densities. Coastal snakes crawled faster than inland snakes at all push-point densities.