[2] In recent decades it has spread as an invasive species to some freshwater waterways and reservoirs of Eastern Europe and to the brackish Baltic Sea.

[4] When conditions are inhospitable, C. pengoi will undergo sexual reproduction, producing resting eggs that can over-winter and repopulate the lake quickly in the spring.

[4] Cercopagis pengoi was brought to the American Great Lakes in ship ballast water from the Black Sea.

[4] The species is transported in the live wells, bait water, and ropes of recreational fishing and boating.

[8] C. pengoi’s wide tolerance levels and ability to reproduce both sexually and asexually makes it a very successful invader.

Asexual reproduction allows for rapid population growth, and then resting eggs which are produced sexually can stick to boats and fishing gear and dispersed into new bodies of water.

[9] In the Baltic and in the Great Lakes, planktivorous fish and mysids are reported to prey on C. pengoi, implying that it has become a new food source.