WDFW LogoWashington Department of Fish & Wildlife
WDFW LogoConservation

To report an AIS
sighting or to find out
more information call

Questions or comments regarding the state's Aquatic Invasive Species and Ballast Water Management Programs may be directed to:

Allen Pleus
AIS Coordinator
(360) 902-2724

View WAC 220-12-090
Classification - Nonnative aquatic
animal species with photos

Cercopagis pengoi (Fishhook waterflea)

Animal Crustaceans
Family: Cercopagidae
Classification: Prohibited

Fish Hook Flea

The Fish hook flea was introduced into the Great Lakes in the 1980's. Most likely in ballast water taken up in the Caspian Sea. The flea is about 1 cm long, with a long spiney tail with a unique loop at the end. The tail comprises about 80% of the flea's length. These long tails become entangled on fishing lines, and on one another, creating clumps that look and feel like wet cotton, with tiny black dots that are the single eyes of each individual. The flea reproduces numerous times in a single season. They feed on zooplankton. Large populations could cause a decline of native zooplankton species, impacting juvenile and small fish that feed on zooplankton, and larger fish that feed on these smaller species. In the areas where they have become established, they have had a negative impact on recreational anglers and could have an impact on commercial fishers if they foul their nets.