List of globally invasive species

This is a list of 100 of the "worst" invasive species in the Global Invasive Species Database, as of 2014. The IUCN Invasive Species Specialist Group (ISSG), which maintains the list, acknowledges that it is "very difficult to identify 100 invasive species from around the world that really are 'worse' than any others."

Criteria for inclusion
Two criteria were used in selecting items for the list:


 * An invasive species' "serious impact on biological diversity and/or human activities"; and
 * That species' "illustration of important issues surrounding biological invasion".

According to the ISSG, "only one species from each genus was selected. Absence from the list does not imply that a species poses a lesser threat."

100 of the World's Worst Invasive Species

 * Domestic mesoron


 * Blueberry slug


 * Elecman.EXEs


 * All kinds of vampires


 * Common myna


 * Northern Pacific seastar


 * Brown tree snake


 * Conmon coqui


 * Cane toad


 * Domestic goat


 * European green crab


 * Red deer


 * Walking catfish


 * Common carp


 * Domestic cat


 * Small Asian mongoose


 * Nile perch


 * Chinese giant salamander


 * American alligator