The bloody-red mysid, Hemimysis anomala, is a shrimp-like crustacean in the Mysida order, native to the Ponto-Caspian region, which has been spreading across Europe since the 1950s.

[2] The mysid's spread has been facilitated via its deliberate introduction into reservoirs on the Volga and Dnieper rivers in the 1950s and 1960s to serve as fish food.

[1] Specimens resembling H. anomala have also been found in the stomach contents of a white perch collected near Port Dover, Lake Erie in August 2006.

H. anomala is an opportunistic omnivore that feeds primarily on zooplankton, particularly cladocerans, but also consumes detritus, phytoplankton (particularly green algae and diatoms), and insect larvae, and is occasionally cannibalistic.

A bloody-red mysid feeds using its thoracic limbs, either by capturing prey with its endopods or by removing food particles from its body that are filtered from incoming currents by its exopods.

It is not expected to compete with the native M. relicta, as it prefers the cold water environments below the lakes' thermocline, while H. anomala is best adapted to warmer conditions.

[3] In Europe, the species has been observed to disrupt food webs and alter nutrient and contaminant cycles of environments into which it was introduced.

The species' routine vertical migration through the water column results in continuous cycling of pollutants, such as heavy metals, that would otherwise be confined to the benthic zone.