鱼类的标准体型是纺锤形，如海洋中的金枪鱼、黄花鱼、鲱鱼、鲈鱼，以及淡水中的鲤鱼、青鱼等都属于纺锤形。 具有纺锤形的鱼类，它们游动起来阻力小，速度快，适合于在水中迅速地追捕食物和灵活地逃避敌害。鲭鱼是典型的纺锤形，它全身密布着较小的鳞片同时在其表面还有一层黏 The standard body size of fishes is spindle-shaped, such as tuna, yellow croaker, herring, perch in the oceans, and common carp and herring in freshwater. Spindle-shaped fish, which swim less resistance, speed, suitable for rapid hunt for food in the water and flexible to evade predators. Mackerel is a typical spindle shape, it is covered with smaller scales throughout the body at the same time there is a layer of sticky