Relating to,designating,or characterized by a tail fin having two symmetrical lobes extending from the end of the vertebral column,as in most bony fishes.

• 正尾的，等形的与一种尾鳍有关的或以其为特点的，这种尾鳍有对称的两叶从脊椎一头延伸出来，大多数多骨鱼均如是。