In this article, we present some morphological and biological information on piranhas.In addition, we also present our own opinions on the risks posed by exotic species.

• 本文简要地介绍了有关“食人鲳”的形态学和生物学信息,并以“食人鲳”为例,对如何看待生物外来种的问题,提出了作者的观点。