heterocercal fin

同根派生

英汉例句

• The lower lobe of the deeply forked caudal fin is longer than the upper lobe.
  尾鳍深叉型，下叶比上叶长。
• Old World freshwater catfishes having naked skin and a long anal fin more or less merged with the eellike caudal fin.
  东半球的淡水鲇鱼，体表无鳞，有类似鳗鱼尾鳍的很长的臀鳍。