proctal fin

• 臀鳍

proctal fin的用法和样例：

例句

1. 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。
2. The male shows elongated rays in its anal fin and yellow pearl organs on the jaws and opercula during breeding season.
   雄鱼的臀鳍鳍条特长，交配季节两颌和鳃盖会长出黄色的珠星。