Swimming behavior in relation to buoyancy in an open swimbladder fish, the Chinese sturgeon
Swimming behavior in relation to buoyancy in an open swimbladder fish, the Chinese sturgeon
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DOI：
10.1111/j.1469-7998.2008.00451.x
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发表时间：
2008-08-01
影响因子：
2
通讯作者：
Miyazaki, N.
中科院分区：
文献类型：
--
作者：
Watanabe, Y.;Wei, Q.;Miyazaki, N.
鱼的鱼囊很容易被水静压力随深度压缩，从而引起浮力的变化。虽然现代鱼类可以通过将血液中的气体分泌到泳囊来调节浮力，但鲟鱼等原始鱼类缺乏这种分泌机制，完全依赖表面吞噬的空气来充气。因此，鲟鱼可能会经历浮力的变化，这将影响它们在不同深度的行为。为了验证这一预测，我们在长江中的七条自由放养的中华鲟鱼中国身上安装了数据记录器，以监测它们的深度利用、拍尾活动、游泳速度和身体倾斜。观察到了两种不同的、特定于个人的行为模式。4条鱼游在浅水区(7-31米)，速度为0.5-0.6米S(-1)，升降幅度为1-2.4米。它们不断地拍打着尾巴，表明它们的浮力与充气的泳囊接近中性。此外，它们偶尔出现在海面上的迹象表明，它们吸入了空气来给自己的泳囊充气。其他三种鱼的大部分时间(88-94%)在106-122米深的河底，活跃度最低。它们偶尔会以0.6m-0.8m的速度向上游，S(-1)用激烈的尾巴，然后被动地滑回底部，方式类似于没有泳囊的鱼。他们的膀胱很可能是被静水压力压塌的，导致负浮力。我们得出的结论是，中华鲟鱼的行为取决于它们的浮力，浮力随着水深的变化而变化，这是由于对泳囊的流体静力压缩。
The swimbladder of fishes is readily compressed by hydrostatic pressure with depth, causing changes in buoyancy. While modern fishes can regulate buoyancy by secreting gases from the blood into the swimbladder, primitive fishes, such as sturgeons, lack this secretion mechanism and rely entirely on air gulped at the surface to inflate the swimbladder. Therefore, sturgeons may experience changes in buoyancy that will affect their behavior at different depths. To test this prediction, we attached data loggers to seven free-ranging Chinese sturgeons Acipenser sinensis in the Yangtze River, China, to monitor their depth utilization, tail-beating activity, swim speed and body inclination. Two distinct, individual-specific, behavioral patterns were observed. Four fish swam at shallow depths (7-31 m), at speeds of 0.5-0.6 m s(-1), with ascending and descending movements of 1.0-2.4 m in amplitude. They beat their tails continuously, indicating that their buoyancy was close to neutral with their inflated swimbladders. In addition, their occasional visits to the surface suggest that they gulped air to inflate their swimbladders. The other three fish spent most of their time (88-94%) on the river bottom at a depth of 106-122 m with minimum activity. They occasionally swam upwards at speeds of 0.6-0.8 m s(-1) with intense tailbeats before gliding back passively to the bottom, in a manner similar to fishes that lack a swimbladder. Their bladders were probably collapsed by hydrostatic pressure, resulting in negative buoyancy. We conclude that Chinese sturgeons behave according to their buoyancy, which varies with depth due to hydrostatic compression of the swimbladder.