The most sold are still tropicals , especially guppies , swordtails and millies , which people like because of their bright colors and because they provide the tank with new young fish .
大部分卖出的依然是热带鱼，尤其是虹鳉，剑尾鱼和米莉。人们喜欢这些鱼的明亮颜色，而且它们能给水族馆提供新的年轻的生命。
millies