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Fishhook Waterflea

Photo by Igor Grigorovich,

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Common Name: Fishhook waterflea
Scientific Name: Cercopagis bengoi
Origin: Eurasia


Fishhook waterfleas are tiny crustaceans less than 1/2″ long with long, sharp, barbed tails. The fishhook waterfleas have a slender spine and prominent S-shaped loop on the tail. Fishhook waterfleas collect in gelatinous globs on fishing equipment and lines.


Fishhook waterfleas thrive in deep lakes but can also be found in shallow lakes and rivers.


Fishhook waterfleas are voracious predators of small zooplankton, like Daphnia, an important food for young native fishes. They reproduce rapidly, and eggs are capable of lying dormant all winter, resistant to drying and freezing. As a result of their sharp spines, smaller fish cannot readily consume them, adding to their explosive populations.


No control methods exist; prevention is key. Since fishing and boating equipment is the most likely means of spread, anglers and water-users must take precautions. Boats and gear should be thoroughly checked, cleaned and dried before entering new waterways.

Regional Distribution

Early Detection

WNY PRISM Priority

Tier 4 – Local Control

Invasive Species Priorities – Tier Chart


The fishhook waterflea is thought to have been introduced by ship ballast water.  It is spread through contaminated boating and fishing gear as well as natural water pathways.


The fishhook waterflea is a prohibited species in New York State – for more information on Prohibited and Regulated Species, visit