African Clawed Frog

Scientific name: Xenopus laevis What Is It? The African clawed frog is a predatory semi-aquatic frog native to sub-Saharan Africa that is highly adaptable to diverse environmental conditions and habitats. They reproduce so rapidly that they can double the population, and range, within 10 years. Similar to bullfrogs, African clawed frogs will eat anything that […]

September 18, 2019
Invasive Zooplankton

Scientific Names: Oithona davisae and Pseudodiaptomus forbesi What Are They? O. davisae and P. forbesi are copepods (small aquatic crustaceans related to shrimp) that are native East Asia. O. davisae is about a half-millimeter long, and P. forbesi is about 1 millimeter long. Are They Here Yet? Yes, invasive zooplankton have been found in the […]

September 18, 2019
Asian Carp

Scientific names: Hypophthalmichthys nobilis, Mylopharyngodon piceus, Ctenopharyngodon idella, Hypophthalmichthys molitrix What Are They? Invasive Asian carp are members of the minnow family that grow to be very large. They are found in both flowing and still water, tolerating a wide range of water quality and weather conditions. These carp tend to consume large amounts of […]

August 26, 2019
Feral Swine

Scientific name: Sus scrofa What Are They? While feral pigs may look similar to domestic pigs, they are much more destructive. They were brought to the United States as domestic pigs from Europe and Asia. Over time, some have escaped or were released intentionally, creating free-ranging feral swine populations. Prolific breeders, they can produce four […]

August 26, 2019
Marine Clams

Scientific names: Nuttallia obscurata and Potamocorbula/Corbula amurensis Featured image credit: User: pintail, Link to observation. What Are They? Nuttallia obscurata, commonly known as the purple varnish, or mahogany clam was first introduced to the United States and Washington from ship ballast water from Asia It is freshwater tolerant and is most abundant in areas […]

August 8, 2019

Scientific name: Myocastor coypu What Is It? Nutria is a medium sized rodent that lives in freshwater environments. It is native to South America. A nutria can grow up to 40 inches from its nose to the tip of its round, rate-like tail. It weighs an average of 12 pounds, although some may reach up […]

August 6, 2019
Mitten Crab

Scientific name: Eriocheir sinensis What Is It? A mitten crab is light brown to green, with brown hairy patches resembling mittens on its claws. It spends most of its life in freshwater, but reproduces in saltwater. A mitten crab can prey on and compete with many native aquatic species, posing a threat to ecosystems and […]

August 6, 2019
Vineyard Snail

Scientific name: Cernuella virgata What Is It? The vineyard snail (occasionally referred to as the Mediterranean white snail) is small (less than 1 inch across) and white or tan in color with dark brown spiral bands. These snails often are found on top of vegetation, particularly crops, where they can survive long periods of hot […]

August 5, 2019
European Green Crab

Scientific name: Carcinus maenas What Is It? The European green crab is a small shore crab that is not necessarily green like its name implies. It typically is found in high intertidal areas and marshes in coastal estuaries and wave-protected embayments. It can live on a variety of surfaces including sand, mudflats, shells, cobble, algae, […]

August 2, 2019
New Zealand Mud Snail

Scientific name: Potamopyrgus antipodarum What Is It? The New Zealand mud snail is a tiny (less than 6 millimeter) aquatic snail that is adaptable to diverse climates and environmental conditions. It is found in freshwater and brackish environments. Is It Here yet? Yes. New Zealand mud snails were first discovered in the lower Columbia River […]

August 2, 2019
Invasive Crayfish

Northern Crayfish (Orconectes virilis) and Red Swamp Crayfish (Procambarus clarkia) What Are They? Crayfish are freshwater crustaceans related to lobsters. In the Pacific Northwest, three species of invasive crayfish are present: northern, red swamp, and rusty. The northern crayfish is native to Montana, Wyoming, the upper Mississippi River, the Great Lakes, and the Hudson River. […]

August 2, 2019
Northern Snakehead

Scientific name: Chana argus What Is It? The northern snakehead is an aggressive freshwater fish that can grow up to 4 feet long. It has been found in a variety of freshwater lakes, swamps, ponds, and streams of various temperatures, but cannot tolerate saltwater. The northern snakehead is native to parts of Asia and Africa. […]

August 2, 2019

Scientific names: Styela clava, didemnum vexillum, and ciona savignyi What Is It? Tunicate, commonly called a sea-squirt, is a primitive marine animal that spends most of its life attached to docks, rocks, or the undersides of boats. A tunicate is built like a barrel. The name “tunicate” comes from the firm, but flexible body covering, […]

August 2, 2019
Zebra and Quagga Mussels

Zebra mussels (dreissena polymorpha) and quagga mussels (dreissena bugenis) What Are They? Zebra and quagga mussels are freshwater mollusks that colonize lakes and rivers. Their preferred habitats include the calm waters upstream of dams. They are most abundant on hard, particularly rocky surfaces. Are They Here Yet? No, but they are only a day’s drive […]

August 2, 2019

Scientific name: Rana catesbeiana What Is It? The bullfrog is the largest frog species in North America. It is found in a variety of freshwater habitats, including ponds, marshes, streams, rivers, canals, reservoirs, ditches, shallow wetlands, and stormwater ponds. Bullfrogs compete with, and prey on, a wide range of native species, and may affect significantly […]

August 1, 2019
Northern Pike

Scientific name: Esox lucius What Is It? The northern pike is a non-native predator of popular sport fish in Washington and is a prohibited species here. It reproduces prolifically and primarily preys on fish smaller than itself, including juveniles of other species. Is It Here Yet? Yes. It has been introduced illegally and established populations […]

July 29, 2019