The Beijing Entry-Exit Inspection and Quarantine Bureau intercepted 10 live poison dart frogs in an overseas parcel on April 18.(Photo/Xinhua)

According to the Chinese Academy of Agricultural Sciences, over 580 alien species had invaded China by the end of 2015. In recent years, some pet lovers have begun to keep special pets such as spiders, ants, turtles and piranhas. Some alien species have turned from guests into hosts and broken the ecological balance.

The Beijing Entry-Exit Inspection and Quarantine Bureau intercepted 10 live poison dart frogs in an overseas parcel on April 18. The frogs were found inside a package mailed from Poland, which was labeled as containing clothing and gifts. The poison dart frogs, also known as poison arrow frogs, are native to Central and South America. Experts said that one gram of the frog's venom could kill 15,000 people.

Many species now present in daily life in China were originally alien, such as trachemys scripta elegans, apple snails, crayfish and water hyacinth. 

According to the Chinese Academy of Agricultural Sciences, of the more than 580 invasive alien species already in China, over 200 of them could potentially cause harm. Of the world's 100 most threatening alien species, as classified by the International Union for Conservation of Nature, over 50 have invaded China. 

The invasive alien species pose a major threat to China's biological diversity, agricultural and animal husbandry production, and public health.