Most tunas and billfishes have a series of keels and finlets near the tail .

许多的金枪鱼以及长喙鱼类在尾部都有一系列的龙骨脊和小鳍。

Tunas , mackerels , and billfishes have made streamlining into an art form .

金枪鱼、青花鱼和剑鱼都使流线型变成了一种艺术形式。

Tunas , mackerels , and billfishes have even more sophisticated adaptations than these to improve their hydrodynamics .

金枪鱼，马鲛鱼，以及长嘴鱼比那些改进他们流体力学的鱼油更复杂的适应性。

These species consist of the so-called principal market tunas and some billfishes .

这些品种包括所谓的主要市场金枪鱼和一些旗鱼。