SWIMMING AND DIVING IN YOUNG LOGGERHEAD SEA-TURTLES (CARETTA-CARETTA L)
SWIMMING AND DIVING IN YOUNG LOGGERHEAD SEA-TURTLES (CARETTA-CARETTA L)
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作者：
DAVENPORT, J;CLOUGH, W
年轻的红海龟（体重< 400克）在95%的游泳时间里采用双后肢同时踢腿。在这种游泳模式下，大型前鳍折叠在甲壳上。当海龟长到超过400 g时，这种游泳方式逐渐被交替的肢体动作所取代，而在一岁动物（1，500 g）中则看不到。前肢的同步运动在年轻的Caretta中比在相似年龄的绿色海龟Chelonia mydas中要少得多。刚孵出的红海龟有很强的浮力，潜水很困难。潜水随着动物的成长而提高，当体重达到300-400 g时，动物将潜入2米以上的深度。尽管它们具有良好的浮力，但年轻的红海龟能够在海底食物有机体上盘旋和进食。
Young loggerhead turtles (< 400 g body weight) employ a simultaneous double hindlimb kick for 95% of their swimming. The large foreflippers are folded against the carapace in this swimming mode. This type of swimming is progressively replaced by an alternate-limb action as the turtles grow beyond 400 g and is not seen in yearling animals (1,500 g). Synchronous forelimb movement is much less common in young Caretta than in green turtles, Chelonia mydas, of similar age. Hatchling loggerheads are positively buoyant and dive with difficulty. Diving improves as the animals grow and by the time a weight of 300-400 g is reached, animals will dive to a depth of more than 2 m. Despite their positive buoyancy, young loggerheads are capable of hovering over and browsing from, benthic food organisms.