Aquatic invasive species (AIS) pose an ongoing threat to Washington's environment and economy. Find out which species are considered invasive in Washington.
| Species | Category | Family | AIS classification |
|---|---|---|---|
| Spectacled salamander (Salamandrina terdigitata) | Amphibians | Salamandridae | Prohibited |
| Spiny crayfish (Euastacus setosus) | Crustaceans | Parastacidae | Prohibited |
| Spiny crayfish (Euastacus spinifer) | Crustaceans | Parastacidae | Prohibited |
| Spiny crayfish (Euastacus valentulus) | Crustaceans | Parastacidae | Prohibited |
| Spiny crayfish (Euastacus woriwuru) | Crustaceans | Parastacidae | Prohibited |
| Spiny crayfish (Astacopis tricornus) | Crustaceans | Parastacidae | Prohibited |
| Spiny Softshell turtle (Apalone spinifer) | Reptiles | Trionychidae | Prohibited |
| Spiny waterflea (Bythotrephes cederstroemi) | Crustaceans | Cercopagidae | Prohibited |
| Spot-Tailed Warty newt (Paramesotriton caudopunctatus) | Amphibians | Salamandridae | Prohibited |
| Spotless Paddle Tail newt (Pachytriton labiatus) | Amphibians | Salamandridae | Prohibited |
| Spotted Paddle Tail newt (Pachytriton brevipes) | Amphibians | Salamandridae | Prohibited |
| Spotted turtle (Clemmys gutatta) | Reptiles | Emydidae | Prohibited |
| Strauch's Spotted newt (Neurergus strauchii strauchii) | Amphibians | Salamandridae | Prohibited |
| Stream Brown frog (Rana sakuraii) | Amphibians | Ranidae | Prohibited |
| Striped newt (Notophthalmus perstriatus) | Amphibians | Salamandridae | Prohibited |
| Suweon Tree frog (Hyla suweonensis) | Amphibians | Hylidae | Prohibited |
| Tago frog (Rana tagoi) | Amphibians | Ranidae | Prohibited |
| Taibai Stream salamander (Batrachuperus taibaiensis) | Amphibians | Hynobiidae | Prohibited |
| Tam Dao Warty newt (Paramesotriton deloustali) | Amphibians | Salamandridae | Prohibited |
| Tarahumara salamander (Ambystoma rosaceum) | Amphibians | Ambystomatidae | Prohibited |
| Tench (Tinca tinca) | Fish | Cyprinidae | Regulated |
| Terentjev's frog (Rana terentievi) | Amphibians | Ranidae | Prohibited |
| Tetraclitella purpurascens (Tetraclitella purpurascens) | Crustaceans | Tetraclitidae | Regulated |
| Three-toed Amphiuma (Amphiuma tridactylum) | Amphibians | Amphiumidae | Prohibited |
| Tiantai frog (Rana tientaiensis) | Amphibians | Ranidae | Prohibited |