The goldfish, which we are used to seeing in aquariums, is not as innocent as it looks. Carassius auratus, as it is called in Latin, risks outcompeting native fish in Swedish waters, according to the Swedish University of Agricultural Sciences' Species Database.
In the latest risk assessment, the goldfish is classified as "high risk", reports Swedish Radio's P4 Göteborg.
The problem arises when goldfish in unknown numbers are released from aquariums and garden ponds and compete for space and food with native species. When the goldfish is released, it changes color and therefore it is difficult to determine how many populations have managed to establish themselves.
