California’s Invaders

Introduction

The Invasive Species Program has identified numerous actual and potential invasive species from which we strive to protect California’s wildlands and waterways. Many invaders have already established populations in various regions of California and occur in different stages of the invasion process. We aim to prevent the spread of these species by educating the public about the species, their impacts, how they spread, and how people can avoid spreading them. In addition, numerous other species that may already be invasive elsewhere in the U.S., but have not yet been introduced or established in California, have been identified as threats to the state’s environment, economy, agricultural interests, and/or human health. By educating the public about these species, their likely impacts, the pathways of introduction, and what to do if they are encountered, we aim to prevent introductions and intercept populations before they are able to establish, spread, and cause harm.

Click on the profiles below to learn about each species’ description, distribution, habitat preference, pathways of spread, impacts, and what to do if you find one. Please note: the list below is far from comprehensive, and we are constantly working to compile additional species fact sheets to add to the list below. If you are looking for information about an invasive species not listed below, email us at Invasives@wildlife.ca.gov.

Taxon-Mammal Mammals

Scientific name Common name Currently present in California Restricted species1 Printable version (PDF)
Myocastor coypus Nutria Yes Yes PDF(opens in new tab)

Taxan Bird Birds

Scientific name Common name Currently present in California Restricted species1 Printable version (PDF)
Cygnus olor Mute swan Yes Yes PDF(opens in new tab)
Molothrus ater Brown-headed cowbird Yes No PDF(opens in new tab)

Taxon Reptile Reptiles

Scientific name Common name Currently present in California Restricted species1 Printable version (PDF)
Nerodia fasciata Southern watersnake Yes Yes PDF(opens in new tab)
Nerodia sipedon Northern watersnake Yes Yes PDF(opens in new tab)
Trachemys scripta elegans Red-eared slider Yes No PDF(opens in new tab)

Amphibians

Scientific name Common name Currently present in California Restricted species1 Printable version (PDF)
Eleutherodactylus coqui Common coqui Yes Yes PDF(opens in new tab)
Lithobates catesbeianus American bullfrog Yes No PDF(opens in new tab)
Xenopus laevis African clawed frog Yes Yes PDF(opens in new tab)

Taxon Fish Fishes

Scientific name Common name Currently present in California Restricted species1 Printable version (PDF)
Family Channidae Snakeheads No Yes PDF(opens in new tab)
Family Characidae Piranhas No Yes PDF(opens in new tab)
Ctenopharyngodon idella Grass carp Yes Yes PDF(opens in new tab)
Esox lucius Northern pike No Yes PDF(opens in new tab)
Hypophthalmichthys molitrix Silver carp No Yes PDF(opens in new tab)
Hypophthalmichthys nobilis Bighead carp No Yes PDF(opens in new tab)
Family Lepisosteidae Gars No Yes PDF(opens in new tab)
Mylopharyngodon piceus Black carp No Yes PDF(opens in new tab)

Taxon Invertebrates Invertebrates

Scientific name Common name Currently present in California Restricted species1 Printable version (PDF)
Dreissena spp. Quagga and zebra mussels Yes Yes PDF(opens in new tab)
Eriocheir senensis Chinese mitten crab Yes Yes PDF(opens in new tab)
Euwallacea spp. (opens in new tab) Polyphagous and Kuroshio
shot hole borers
Yes No
Pomacea canaliculata Channeled apple snail Yes Yes PDF(opens in new tab)
Potamopyrgus antipodarum New Zealand mudsnail Yes Yes PDF(opens in new tab)

1 Restricted species are on CDFW’s List of Restricted Live Animals (California Code of Regulations Title 14, Section 671(opens in new tab)), and therefore may not be imported, transported, or possessed without a permit issued by CDFW. For more information on why these species are restricted, visit our Laws and Regulations page.

CDFW Invasive Species Program
P.O. Box 944209, Sacramento CA 94244-2090
Invasives@wildlife.ca.gov

Fisheries Branch
1010 Riverside Parkway, West Sacramento, CA 95605 | Fisheries@wildlife.ca.gov