Bloody red shrimp

Scientific Name: Hemimysis anomala

NOAA GLERLCopyright Info

NOAA GLERLCopyright Info

Identification: The bloody red shrimp is translucent or ivory-yellow in color, but can change its body and tail color to deep red in response to light and temperature conditions. This species tends to be darker red when inhabiting shaded areas. It has large, black eyes on short stalks. The bloody red shrimp is distinguishable under a microscope or magnifying glass from similar Great Lakes native species by its square tail, which is short with a long spine at each corner. The bloody red shrimp also lives close to shore, while similar native species live in deeper water.

Size: Mature individuals range between 0.25-0.5 inch (6-13 mm) in length.

Native Range: The bloody red shrimp is native to near-shore areas of the Black, Azov, and eastern Ponto-Caspian seas, as well as rivers in nearby areas of eastern Europe.

Table 1. Great Lakes region nonindigenous occurrences, the earliest and latest observations in each state/province, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Hemimysis anomala are found here.

Full list of USGS occurrences

State/ProvinceYear of earliest observationYear of last observationTotal HUCs with observations†HUCs with observations†
Illinois200620163Lake Michigan; Little Calumet-Galien; Pike-Root
Indiana201620161Lake Michigan
Michigan200620166Boardman-Charlevoix; Lake Erie; Lake Huron; Lake Michigan; Muskegon; Pere Marquette-White
New York200620164Lake Erie; Lake Ontario; Oneida; Seneca
Ohio200920111Lake Erie
Pennsylvania201920191Lake Erie
Wisconsin200720186Beartrap-Nemadji; Door-Kewaunee; Lake Michigan; Lake Superior; Lower Fox; Milwaukee

Table last updated 9/30/2019

† Populations may not be currently present.

* HUCs are not listed for areas where the observation(s) cannot be approximated to a HUC (e.g. state centroids or Canadian provinces).

Means of Introduction: Bloody red shrimp's introduction into the Great Lakes appears to be the result of ballast water discharge from transoceanic ships.

Status: This species was first reported in southeastern Lake Ontario and in a channel connecting Muskegon Lake to Lake Michigan in 2006. Populations are well-established in Lake Ontario, Lake Erie, Lake Huron, and Lake Michigan, but have not been found in Lake Superior.

Remarks: This shrimp can adapt to freshwater environments, but it normally lives in brackish water, which has more salt than freshwater but not as much as seawater.

Bloody red shrimp's reaction to light, daily migration behavior, and rapid swimming make monitoring difficult. During daylight hours, swarms may hide in the shade. Swarms are more easily detected at night, when shining a bright light on calm water will cause individuals to rapidly disperse.

Author: Illinois-Indiana Sea Grant

Contributing Agencies:
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Revision Date: 9/25/2012

Citation for this information:
Illinois-Indiana Sea Grant, 2019, Bloody red shrimp: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, and NOAA Great Lakes Aquatic Nonindigenous Species Information System, Ann Arbor, MI,, Revision Date: 9/25/2012, Access Date: 10/13/2019

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.