Any of various aquatic crustaceans of the subclass Branchiopoda,such as the fairy shrimp and water flea,characterized by a segmented body and flattened,leaflike thoracic appendages.

• 鳃足动物一种鳃足亚纲水生甲壳类动物，如神仙虾和水蚤，特征是身体分节，具有平直叶状的胸腹附属结构。