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Bloody Red Shrimp

Bloody Red Shrimp (Hemimysis anomala) Photo Credit: NOAA Great Lakes Environmental Research Lab

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Common Name: Bloody red shrimp
Scientific Name: Hemimysis anomala
Origin: Ponto-Caspian Sea, Black Sea and the Azov Sea


The bloody red shrimp are translucent ivory-yellow with red spots. They have dark brown eyes on opposite sides of the head, and the tail is square with two spines at the end. Similar to our native opossum shrimp, bloody red shrimp are smaller and more red in color; measuring less than 1/2”. Bloody red shrimp exhibit pigmented red chromatophores (bright red to reddish-orange coloring) around the head (carapace) and tail (telson). Its length when fully matured can range from 6-13 mm, with the females being slightly larger than the males.


The bloody red shrimp can be found in habitats that are associated with rocky bottoms or hard structures. They tend to avoid direct sunlight and be found in water depths of about 50 m. They also prefer slow-moving waters, but can be found along rocky, wave-exposed shorelines. The bloody red shrimp now resides in the Great Lakes.


Although the potential impact on the Great Lakes is currently unknown, evidence from its native range in Europe show a potential threat to native fish populations due to its diet of algae and zooplankton, which is typically food for young fish. In Europe, they have also been recorded to speed up the silica cycling in the water, which resulted in blooms of diatoms (a type of phytoplankton), and in a few cases has led to the coating of silica on pipes.


The best way to manage the spread of the bloody red shrimp is to properly clean, drain and dry your boats and equipment before moving from one body of water to another. Also, when releasing plants and fish back into the water, make sure it is the water which they are from.

Regional Distribution

Locally Common – Great Lakes

WNY PRISM Priority

Tier 5b – Research

Invasive Species Priorities – Tier Chart


Bloody red shrimp were introduced to the Great Lakes through ship ballast water. They are spread by boats and trailers moving between bodies of water and through natural aquatic pathways.


Bloody red shrimp are a prohibited species in New York State – for more information on Prohibited and Regulated Species, visit