* Red Alert species: Species not yet established in Maryland but considered to be of high risk.
Key Code	Scientific Name	Common Name	Details
2, 3	Branta canadensis	Canada Goose (non-migratory)
1, 2, 3, 4	Channa argus	Northern Snakehead
1, 2, 3	* Ctenopharyngodon idella	Grass Carp
2, 3	Cygnus olor	Mute Swan
2	Gambusia affinis	Eastern Mosquitofish (non-tidal)
1, 2, 3	Myocastor coypus	Nutria
2, 4	Rattus norvegicus	Norway Rat