Sato Katsufumi, Mitani Yoko, Cameron Michael F, Siniff Donald B, Naito Yasuhiko
National Institute of Polar Research, 1-9-10 Kaga, Itabashi, Tokyo 173-8515, Japan.
J Exp Biol. 2003 May;206(Pt 9):1461-70. doi: 10.1242/jeb.00265.
Aquatic animals use a variety of strategies to reduce the energetic cost of locomotion. Efficient locomotion is particularly important for breath-holding divers because high levels of exercise may quickly deplete oxygen reserves, leading to the termination of a dive. We investigated the swimming behavior of eight adult Weddell seals, which are proficient divers, in McMurdo Sound, Antarctica. A newly developed data logger was attached to free-ranging females at their own breeding sites to record swimming speed, depth, two-dimensional accelerations (stroke frequency and body angle) and temperature. All seals conducted multiple deep dives (the mean dive depth range for each animal was 223.3+/-66.5-297.9+/-164.7 m). Prolonged gliding while descending was observed with thinner females (N=5 seals). But the fatter females (N=3 seals) exhibited only swim-and-glide swimming, characterized by intermittent stroking and fluctuating swim speed, throughout their descent and ascent. The body angles of four of the seals were restricted to less than 30 degrees by the location of breathing holes in the ice and the slope of local bathymetric features. Of these four, the three fatter seals adopted the stroke-and-glide method while the other thinner seal descended with prolonged periods of gliding. Prolonged gliding seems to be a more efficient method for locomotion because the surface time between dives of gliding seals was significantly less than that of stroking animals, despite their same stroke frequencies.
水生动物采用多种策略来降低运动的能量消耗。高效的运动对于屏气潜水者尤为重要，因为高强度运动可能会迅速耗尽氧气储备，导致潜水终止。我们在南极洲麦克默多湾对八只成年威德尔海豹（熟练的潜水者）的游泳行为进行了调查。一种新开发的数据记录器被安装在自由放养的雌性海豹在其繁殖地，以记录游泳速度、深度、二维加速度（划水频率和身体角度）和温度。所有海豹都进行了多次深潜（每只动物的平均潜水深度范围为223.3±66.5 - 297.9±164.7米）。较瘦的雌性海豹（N = 5只）在下降时观察到长时间的滑行。但较胖的雌性海豹（N = 3只）在整个下降和上升过程中只表现出游泳和滑行的游泳方式，其特点是间歇性划水和波动的游泳速度。由于冰面上呼吸孔的位置和当地测深特征的坡度，其中四只海豹的身体角度被限制在30度以内。在这四只海豹中，三只较胖的海豹采用划水和滑行的方法，而另一只较瘦的海豹则长时间滑行下降。长时间滑行似乎是一种更有效的运动方式，因为尽管滑行海豹和划水动物的划水频率相同，但滑行海豹潜水之间的水面停留时间明显少于划水动物。
