Hemimysis anomala

This photo shows a Ponto-Caspian shrimp, the 'bloody red mysid' Hemimysis anomala. Its recent introduction to the Great Lakes was predicted, based on its invasion history in Europe (Ricciardi & Rasmussen 1998). It was discovered in Lake Michigan and Lake Ontario more than a decade after ballast water exchange procedures became mandatory, suggesting that those procedures were not sufficient to prevent the arrival of all ship-vectored invaders (Ricciardi & MacIsaac 2008). One possible reason for this is that inbound ships declaring "No Ballast On Board" (NOBOB ships) were exempt from the procedures, despite carrying residual water that are known to harbour organisms. Therefore, in 2006, Canada implemented new regulations for the management of residual water in NOBOB ships. The future will determine if this strategy is successful.

This species continues to spread; in July 2008, it was found in the St. Lawrence River (Kestrup & Ricciardi 2008).

See a factsheet for H. anomala (Kipp & Ricciardi 2007), prepared for NOAA's Great Lakes Aquatic Nondigenous Information System (GLANSIS). For more information on its potential impacts, see this paper.