The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

Palaemonetes kadiakensis
Palaemonetes kadiakensis
(Mississippi Grass Shrimp)
Native Transplant
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Palaemonetes kadiakensis (M. J. Rathbun, 1902)

Common name: Mississippi Grass Shrimp

Synonyms and Other Names: Ghost Shrimp, Glass shrimp, Glass Prawn, Popcorn Shrimp (Anderson 1985), Freshwater Prawn (Pigg and Cheper 1998)

Taxonomy: available through www.itis.govITIS logo

Identification: Palaemonetes kadiakensis is a small translucent (sometimes clear) shrimp with tiny red specks throughout the body on some specimens (Page 1985, Fofonoff et al. 2016). Palaemonids are characterized by having the first two pairs of pereopods modified as chelipeds, the first being smaller and adorned with setae and the second being longer and more elongate than the first. This species has a humped abdomen at the third segment, and large dark brown to tan pigmented eyes (Page 1985, Hobbs and Jass 1988). Bright green vegetation is often visible in the intestines, and orange eggs can be seen through the body in mature females (Walls 2009). The eggs are spherical and around 1 mm in diameter (Page 1985, Walls 2009). This species is similar in appearance to other Palaemonetes species (grass shrimp) but can be identified by a set of three characteristics:

1) The number of rostrum “horn” teeth for the species is between 6 -8, usually 7, on the dorsal side and 2-3 on the ventral side (Anderson 1985, Page 1985, Walls 2009).

2) The posterior telson spines of the “tail fin” are also shifted far back at the same level with the larger spines on the back edge of the telson (Walls 2009). See below for link to figure of shrimp anatomy

3) Palaemonetes kadiakensis can be differentiated from P. paludosus by the number of large spines at the tip of the male second pleopods “swimming legs” (P. kadiakensis has three and P. paludosus has four) (Page 1985, Walls 2009). Note: strong magnification is needed to see this last characteristic.

Size: About 50 mm in total length (Page 1985, Pennak 1989), with the record being 53 mm (Meehan 1936). Females are generally slightly larger than males.

Native Range: Palaemonetes kadiakensis's ranges from northeastern Mexico, north through the Mississippi River and Ohio River Basins to Minnesota and the shores of Lakes Ontario, Erie, and Michigan. This specie's southeastern range includes the Gulf Coast from Texas to northern Florida (see Page 1985; Fig. 87, p. 360 and Hobbs and Jass 1988; Fig. 76, p.120). The shrimp is also native in the Red River in Oklahoma and Texas (Pigg and Cheper 1998). 

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Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Nonindigenous Occurrences:

Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, 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 Palaemonetes kadiakensis are found here.

StateYear of earliest observationYear of last observationTotal HUCs with observations†HUCs with observations†
California201220173San Diego; San Joaquin Delta; Upper Cosumnes
Idaho201720171Lower Boise
Kansas198019872Ninnescah; Upper Verdigris
Ohio200620102Little Scioto-Tygarts; Upper Ohio-Shade
Pennsylvania200620072Lower Monongahela; Upper Monongahela
West Virginia201020101Upper Ohio-Shade

Table last updated 5/25/2018

† Populations may not be currently present.

Ecology: Palaemonetes kadiakensis is primarily found in low gradient freshwater habitats but can also be found in brackish conditions (Christmas and Langley 1973) in salinities of up to 20 ppt but have a lethal limit of 25 ppt (Strenth 1976). Palaemonetes kadiakensis generally prefers waters with high visibility and relatively low velocities (Pigg and Cheper 1998, Hobbs and Jass 1988, Barko and Hrabik 2004); however, Pigg and Cheper (1998) found it in large turbid impoundments and small turbid ponds.  Palaemonetes kadiakensis has also been found in a rapidly flowing stream in Louisiana (Bouchard and Robinson 1980) and in vernal pools, wetlands and streams with abundant living aquatic vegetation and clear water (Page 1985, Pigg and Cheper 1988, Simon and Thoma 2003). In Arkansas, it appears to be associated with American lotus (Nelumbo lutea), swamp smartweed (Polygonum hydropiperoides var. opelosanum), water milfoil (Myriopyllium sp.) and marsh mermaidweed (Proserpinacea palustris) (Robinson and McAllister 2011). In Pennsylvania, where it is introduced, it was collected from areas with a mixture of eel grass (Vallisneria americana), pondweeds (Potamogeton spp.), and coontail (Ceratophyllum demersum) (Kimmel and Argetn 2008).

This species mainly feeds on algae (diatoms and green algae) but will also consume living vascular plants (Nielsen and Reynolds 1975, Weisberg 2006, reviewed in Hobbs 1993). This species will also feed on aquatic insects and detritus from both plants and animals (Nielsen and Reynolds 1975). Many populations of P. kadiakensis are declining from high turbidity levels and wetland loss (Thoma 1999). Smith (1979) associated the declines in populations with loss of aquatic vegetation in the species’ habitat.

Palaemonetes kadiakensis reproduce sexually. This species has an annual life cycle with reproduction (indicated by egg-bearing females) occurring through much of its range (Arkansas, Illinois, Indiana, Michigan, Pennsylvania) from April to August (Creaser 1931, Page 1985, Simon and Thoma 2003, Kimmel and Argent 2008, Robinson and McAllister 2011). In the southern portion of its range, (Louisiana) reproduction is extended from February to October (White 1949). Robinson and McAllister (2011) found a sex ratio of 1 (male): 1.9 (female). In Illinois, females are reproductive around 30-39 mm in total length and carry on average 87 eggs in a mass (Page 1985). In Arkansas, Robinson and McAllister (2011) found 38-141 (mean =67.7) eggs per female. The P. kadiakensis larvae are free-swimming and show rapid growth through the fall (Nielsen and Reynolds 1977). Juvenile shrimps mature in the spring and are reproductive at one year of age and then die (Page 1985). Larval development for this species has been described in detail by Broad and Hubschman (1963).

Means of Introduction: Most likely through aquarium (Fofonoff et al. 2016) or bait release as the species is used as bait and fish food, especially in trout hatcheries (Holthuis 1980). They are readily available for sale on Internet commerce sites. It’s also possible the shrimp are hitchhiking with boats or in ballast water (Weisberg 2006).

Status: Established in various locations in California and Idaho, in the Ohio River (Ohio and West Virginia), and in Monongahela drainage (Pennsylvania).

Impact of Introduction: There are no documented economic or ecological impacts for this species (Fofonoff et al. 2016). However, this shrimp is a potential competitor with the California Freshwater Shrimp (Syncaris pacifica), a native in some freshwater streams in California (Brown and Hieb 2014). In general, palaemonids are quite aggressive, using their major chilpeds in agnostic interactions and predation. Palaemonetes kadiakensis, much like P. paludosus, is an important link between benthic and water column habitats, helping energy flow and turnover of detritus (Baranowski 2011), and is an important food resource for juvenile fishes (Hayden et al. 1963).

Palaemonetes kadiakensis serves as a host for various symbiotic and parasitic ciliates and trematodes (Carney and Brooks 1991, Felgenhauer 1982, Landers et al. 1996, Landers and Jones 2009, Browning and Landers 2012), and the aquatic fungi Saprolegnia parasitica and Achlya flagellate have been found to infect laboratory-reared larval P. kadiakensis (Hubschman and Schmidt 1969). Palaemonetes kadiakensis has also been shown to be a potential reservoir for the yellow head virus, an important pathogen to shrimp aquaculture (Ma 2008).  Introduction and spread of the shrimp host to new habitats may facilitate the spread of these associated organisms.

References: (click for full references)

Anderson, G. 1985. Species profiles: life histories and environmental requirements of coastal fishes and invertebrates (Gulf of Mexico): grass shrimp. U.S. Fish Wildl. Serv. Biol. Rep. 82(11.35) U.S. Army Corps of Engineers, TR EL-82-4.

Baranowski, C. 2011. Palaemonetes paludosus, Animal Diversity Web. http://animaldiversity.org/accounts/Palaemonetes_paludosus/. Accessed on 08/28/2017.

Barko, V.A. and D.P. Herzog. 2003. Relationships among side channels, fish assemblages, and environmental gradients in the unimpounded upper Mississippi River. Journal of Freshwater Ecology 18:377-382.

Bouchard, R.W. and H.W. Robinson. 1980. An inventory of the decapod crustaceans, crayfishes and shrimps, of Arkansas. Proceedings of the Arkansas Academy of Science 34:22-30.

Broad, A. C. and J.H. Hubschman. 1963. The larval development of Palaemonetes kadakiensis (M. J. Rathbun) in the laboratory. Transactions of the American Microscopical Society 82:185-197.

Brown, T. and K. A. Hieb. 2014. Status of the Siberian Prawn, Exopalaemon modestus, in the San Francisco Estuary. San Francisco Estuary and Watershed Science 12.

Browning, J.S. and S.C. Landers. 2012. Exuviotrophic apostome ciliates from freshwater decapods in southern Alabama (USA) and a description of Hyalophysa clampi n. sp. (Ciliophora, Apostomatidae). European Journal of Protistology 48:207-2014.

Carney, J.P. and D.R. Brooks. 1991. Phylogenetic analysis of Alloglossidium Simer, 1929 (Digenea: Plagiorchiiformes: Macroderoididae) with discussion of the origin of truncated life cycle patterns in the genus. Journal of Parasitology 77:890-900.

Christmas, J.Y., and W. Langley. 1973. Estuarine vertebrates, Mississippi. Cooperative Gulf of Mexico Estuarine Inventory and Study: 320-434.

Creaser, E.P. 1931. The Michigan decapod crustaceans. Papers of the Michigan Academy of Sciences Arts, and Letters 13:257-276.

De Grave, S. and C. Rogers. 2013. Palaemonetes kadiakensis. The IUCN Red List of Threatened Species 2013. http://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T197722A2497462.en. Accessed on 08/29/2017.

Distler, D.A. and D.E. Bleam. 1988. Palaemonetes kadiakensis Rethburn in Kansas. Transactions of the Kansas Academy of Science 91(3-4):190-191.

Felgenhauer, B.E. 1982. A new species of Lagenophrys (Ciliophora: Peritrichida) from the fresh-water shrimp Palaemonetes kadiakensis. Transactions of the American Microscopical Society 101:142-150.

Fofonoff, P.W., G.M. Ruiz, B. Steves, and J.T. Carlton. 2016. National Exotic Marine and Estuarine Species Information System. Smithsonian Environmental Research Center, Washington, D.C. http://invasions.si.edu/nemesis/. Accessed on 08/29/2017.

Hayden, R. P. and R. D. Ringo. 1963. Introduction of Palaemonetes paludosus, a Freshwater Shrimp, into the Lower Colorado River. California Fish and Game, 49(4):304-306.

Hobbs, H.H., III. 1993. Trophic relationships of North American freshwater crayfishes and shrimps. Milwaukee Public Museum Contributions in Biology and Geology 85:1-110. *in lit

Hobbs, H.H., III, and Jass, J.P. 1988. The crayfishes and shrimp of Wisconsin. Milwaukee Public Museum, Milwaukee, WI.

Holthuis, L.B. 1980. FAO species Catalogue. Vol. 1 - Shrimps and prawns of the world. An annotated catalogue of species of interest to fisheries. Volume FAO Fisheries Synopsis No. 125, Vol. 1. Food and Agriculture Organization of the United Nations.

Hubschman, J.H. and Schmidt, J.A. 1969. Primary mycosis in shrimp larvae. Journal of Invertebrate Pathology 13:351-357.

Huggins, D.G. 1980. The occurrence of the glass shrimp, Palaemonetes kadiakensis Rathburn in Kansas. Technical Publ. State Biological Survey Kansas 9:12-14.

Kimmel, W.G. and D.G. Argent. 2008. Occurrence and distribution of the glass shrimp (Palaemonetes kadiakensis) in the Monongahela River, Pennsylvania. Journal of the Pennsylvania Academy of Science 82(2-3):79-81. 

Landers, S.C., A. Confusione, and D. Defee. 1996. Hylophysa bradburyae sp. n., a new species of apostome ciliate from the grass shrimp Palaemonetes kadiakensis. European Journal of Protistology 32:372-379.

Landers, S.C. and R.D. Jones. 2009. Pathology of the trematode Alloglossidium renale in the freshwater grass shrimp Palaemonetes kadiakensis. Southeastern Naturalist 8:599-608.

Ma, Hongwei. 2008. Yellow head virus: transmission and genome analyses. Ph.D. dissertation 1149. University of Southern Mississippi, Hattiesburg, MS. Available online at http://aquila.usm.edu/dissertations/1149.

McGuire, E. J. 1961. The influence of habitat NaCl concentrations on the distribution of two species of Palaemonetes. Proceedings of the Louisiana Academy of Science 264: 507-525.

Meehan, O.L. 1936. Notes on the freshwater shrimp Palaemonetes spaludosa (Gibbes). Transactions of the American Microscopical Society 55:433-441.

Nielsen, L. A., and J. B. Reynolds. 1975. Fresh-water shrimp natural food for pond fishes. Farm Pond Harvest 9(2):8-9.

Nielsen, L. A., and J. B. Reynolds. 1977. Population characteristics of a freshwater shrimp. Palaemoneles kadiakensis Rathbun. Missouri Academy of Science Transactions 10(11):44-57.

Page, L. M. 1985. The crayfishes and shrimps (decapods) of Illinois. Ill. Nat. Hist. Surv. Bull., 33(4):335-447.

Pennak, R. W. 1989. Fresh-water invertebrates of the United States, 3rd ed. John Wiley & Sons, New York.

Pigg, J. and N.J. Cheper. 1998. Additional observations on the distribution and habitats of Palaemonetes kadiakensis Rathburn (Crustacea: Decapoda) in Oklahoma, 1992 to 1996. Proceedings of the Oklahoma Academy of Science 78:119-122.

Robinson, H.W. and C.T. McAllister. 2011. Geographic distribution and life history aspects of the freshwater shrimps, Macrobranchium ohione and Palaemonetes kadiakensis (Decapoda: Palaemonidae), in Arkansas. Journal of the Arkansas Academy of Science 65:98-110.

Simon, T.P. and R.F. Thoma. 2003. Distribution patterns of freshwater shrimp and crayfish (Decapoda: Cambaridae) in the Patoka River Basin of Indiana. Proceedings of the Indiana Academy of Science 112(2):175-185.

Strenth, N.E. 1976. A review of the systematics and zoogeography of the freshwater species of Palaemonetes heller of North America (Crustacea: Decapoda). Smithsonian Contrib. Zool 228.

Walls, J.G. 2009. Crawfishes of Louisiana. Louisiana State University Press, Baton Rouge, LA.

Weisberg, D. 2006. Shrimp -- that's right, shrimp! -- found in the Monongahela River. Pittsburgh Post Gazette. (August 23, 2006) http://www.post-gazette.com/pg/06235/715487-113.stm.

White, F.A. 1949. Preliminary notes on the breeding season of Palaemonetes kadiakensis Rathbun in the Baton Rouge area. Proceedings of the Louisiana Academy of Science 12:71-74.

Author: Daniel, W.M. and Benson, A.J.

Revision Date: 8/16/2019

Citation Information:
Daniel, W.M. and Benson, A.J., 2019, Palaemonetes kadiakensis (M. J. Rathbun, 1902): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=2620, Revision Date: 8/16/2019, Access Date: 8/18/2019

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.


The data represented on this site vary in accuracy, scale, completeness, extent of coverage and origin. It is the user's responsibility to use these data consistent with their intended purpose and within stated limitations. We highly recommend reviewing metadata files prior to interpreting these data.

Citation information: U.S. Geological Survey. [2019]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [8/18/2019].

Contact us if you are using data from this site for a publication to make sure the data are being used appropriately and for potential co-authorship if warranted. For queries involving fish, please contact Matthew Neilson. For queries involving invertebrates, contact Amy Benson.