Responses of hatchling sea turtles to rotational displacements
Responses of hatchling sea turtles to rotational displacements
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DOI：
10.1016/s0022-0981(03)00002-9
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发表时间：
2003-03-25
影响因子：
2
通讯作者：
Lohmann, KJ
中科院分区：
文献类型：
--
作者：
Avens, L;Wang, JH;Lohmann, KJ
海龟幼崽从地下巢中出来后，会通过冲浪区迁徙到开阔的海洋。在这种迁徙过程中，海浪和水流都会不可预测地将海龟从迁徙的方向上旋转，从而扰乱孵化的方向。此外，海浪会导致海龟翻滚和俯仰，迫使孵化出的海龟进入陡峭的倾斜位置，从而暂时阻碍向前游泳。为了保持朝向大海的方向并在水柱中保持直立，孵化出来的幼崽必须不断地补偿这种位移。作为确定如何实现这一目标的第一步，我们研究了黑头草(Caretta aretta L.)的反应。海龟孵化到旋转位移，包括偏航、侧滚和俯仰。孵化后的幼体对水平面(偏航)的旋转做出反应，将后鳍伸向与旋转方向相反的一侧。因此，鳍状肢可能起到了方向舵的作用，帮助海龟回到原来的方向。海龟对翻滚平面上的旋转做出反应，其前鳍的典型动作是在重力的作用下使孵化出的海龟保持直立。最后，孵化出来的幼鸟对俯仰面的旋转做出反应，后鳍的运动似乎可能会减少或抵消俯仰运动。因此，这些实验的结果表明，年幼的海龟从巢中出来时，拥有一套刻板的行为反应，这些反应具有抵消旋转位移的功能，使动物能够保持平衡，并有助于有效地向公海移动。(C)2003 Elsevier Science B.V.保留所有权利。
After emerging from underground nests, sea turtle hatchlings migrate through the surf zone and out to the open ocean. During this migration, both waves and water currents can disrupt hatchling orientation by unpredictably rotating the turtles away from their migratory headings. In addition, waves cause turtles to roll and pitch, temporarily impeding forward swimming by forcing the hatchlings into steeply inclined positions. To maintain seaward orientation and remain upright in the water column, hatchlings must continuously compensate for such displacements. As a first step toward determining how this is achieved, we studied the responses of loggerhead (Caretta caretta L.) sea turtle hatchlings to rotational displacements involving yaw, roll, and pitch. Hatchlings responded to rotations in the horizontal plane (yaw) by extending the rear flipper on the side opposite the direction of rotation. Thus, the flipper presumably acts as a rudder to help turn the turtle back toward its original heading. Turtles responded to rotations in the roll plane with stereotypic movements of the front flippers that act to right the hatchlings with respect to gravity. Finally, hatchlings responded to rotations in the pitch plane with movements of the hind flippers that appear likely to curtail or counteract the pitching motion. Thus, the results of these experiments imply that young sea turtles emerge from their nests possessing a suite of stereotypic behavioral responses that function to counteract rotational displacements, enable the animals to maintain equilibrium, and facilitate efficient movement toward the open sea. (C) 2003 Elsevier Science B.V. All rights reserved.