small usually brightly-colored viviparous surface-feeding fishes of fresh or brackish warm waters; often used in mosquito control
同义词：poeciliid fishpoeciliidlive-bearer
freshwater fish of Central America having a long swordlike tail; popular aquarium fish
同义词：swordtailhelleriXyphophorus helleri
英汉双解大词典
topminnow/ˈtɒpˌmɪnəʊ/
1.
N（名词）
any of various small American freshwater cyprinodont fishes that are either viviparous (genera Heterandria, Gambusia, etc) or egg-laying (genus Fundulus) 食蚊鱼