Invasion History

First Non-native North American Tidal Record:
First Non-native West Coast Tidal Record:
First Non-native East/Gulf Coast Tidal Record:

General Invasion History:

Upogebia affinis is native to the Atlantic Coast of North America from Cape Cod to Rockport, Texas. Its range was formerly given as Massachusetts to Brazil (Williams 1984), but the southern records represent distinct species, U. felderi, from Mexico, and U. paraffinis, from Brazil (Williams 1993). Upogebia affinis occurs on mudflats and muddy sediments from the intertidal zone to 29 m (Williams 1984).

North American Invasion History:

Invasion History on the West Coast:

In 1912, the RV 'Albatross' dredged four specimens of Upogebia affinis (two males, two females) from San Francisco Bay (USNM 213285, Cohen and Carlton 1995; US National Museum of Natural History 2007). These are the only known specimens of this shrimp from the Pacific Ocean. We consider this a failed introduction, probably with Eastern Oyster (Crassostrea virginica) transplants, or with ballast water.

Invasion History on the East Coast:

Upogebia affinis is considered native to the East Coast of North America, but two early records from the Gulf of Maine could be the result of transplants of Eastern Oysters from southern regions (Long Island Sound or Chesapeake Bay) to New England waters, or perhaps long-distance dispersal of larvae. Specimens were collected in Wellfleet, Massachusetts, an oyster-growing area on the north side of Cape Cod in 1879 (USNM 2994, Williams 1984, US National Museum of Natural History 2007) and in Eastport, Maine, in 1864 (YPM 40643, Yale Peabody Museum 2009). We have no information on the current status of U. affinis in the Gulf of Maine and because of the possibility of natural dispersal, we consider this species to be cryptogenic here.


Upogebia affinis is a burrowing shrimp which superficially resembles a small lobster, with large claws on the front pair of legs. The exoskeleton is weakly calcified, with a parchment-like texture. The rostrum is well-developed, with a stout spine on each side, and projections over the eyes. The anterior portion of the carapace is flat-topped rather than rounded and is rough and covered with short, rigid hairs. The chelipeds (claw-legs) are stout, and fringed on the underside with long hairs, and with a toothed ridge above. The dactyl (movable finger) of the claw is longer than the fixed finger. The first pair of walking legs is hairy at the tips and along the lower margin. The abdomen widens from the first to the fourth segment, posteriorly, and then narrows at the fifth segment. The color is gray, blue, or yellowish-gray, with light blue on the fifth segment, the middle of the telson, and at the base of the antenna (Gosner 1978; Williams 1984). Larval development was described by Sandifer (1973).


Taxonomic Tree

Kingdom:   Animalia
Phylum:   Arthropoda
Subphylum:   Crustacea
Class:   Malacostraca
Subclass:   Eumalacostraca
Superorder:   Eucarida
Order:   Decapoda
Suborder:   Pleocyemata
Infraorder:   Thalassinidea
Genus:   Upogebia
Species:   affinis


Gebia affinis (Say, 1818)

Potentially Misidentified Species

Upogebia felderi
Known only for the Rio Carizzo estuary, Tamaulipas, Mexico, Gulf of Mexico

Upogebia paraffinis
Known only from Sao Paulo State, Brazil

Upogebia pugettensis
Blue Mudshrimp, NE Pacific



Upogebia affinis lives in communal burrows in estuarine mudflats and shallow subtidal waters. Spawning occurs in spring to fall, peaking at 25-27⁰C. Females can carry up to 10,000 eggs on their pleopods. Eggs hatch into planktonic larvae which hatch into planktonic zoeae with a shrimplike appearance. The larvae go through four molts, before settling as a postlarvae (Williiams 1984).

Trophic Status:




General HabitatUnstructured BottomNone
General HabitatOyster ReefNone
General HabitatSalt-brackish marshNone
Salinity RangeMesohaline5-18 PSU
Salinity RangePolyhaline18-30 PSU
Salinity RangeEuhaline30-40 PSU
Tidal RangeSubtidalNone
Tidal RangeLow IntertidalNone
Vertical HabitatEndobenthicNone

Tolerances and Life History Parameters

Minimum Salinity (‰)3Experimental (Williams 1984)
Maximum Salinity (‰)35Probaly tolerates higher salinities.
Minimum Reproductive Salinity13Larval occurrence (Williams 1984)
Maximum Reproductive Salinity32.4Larval occurrence (Williams 1984)
Maximum Length (mm)60Williams 1984
Broad Temperature RangeNoneCold temperate-Tropical
Broad Salinity RangeNoneMesohaline-Polyhaline

General Impacts

To our knowledge, Upogebia affinis is not established in introduced areas, and has no reported impacts, outside its native range.

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
CAR-VII Cape Hatteras to Mid-East Florida 1818 Native Estab
CAR-I Northern Yucatan, Gulf of Mexico, Florida Straits, to Middle Eastern Florida 0 Native Estab
NA-ET3 Cape Cod to Cape Hatteras 0 Native Estab
NA-ET2 Bay of Fundy to Cape Cod 1864 Crypto Unk
NEP-V Northern California to Mid Channel Islands 1912 Def Failed
P090 San Francisco Bay 1912 Def Failed
N180 Cape Cod Bay 1879 Crypto Estab
N010 Passamaquoddy Bay 1864 Crypto Unk

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude


Cohen, Andrew N.; Carlton, James T. (1995) Nonindigenous aquatic species in a United States estuary: a case study of the biological invasions of the San Francisco Bay and Delta, U.S. Fish and Wildlife Service and National Sea Grant College Program (Connecticut Sea Grant), Washington DC, Silver Spring MD.. Pp. <missing location>

Gosner, Kenneth L. (1978) A field guide to the Atlantic seashore., In: (Eds.) . , Boston. Pp. <missing location>

Sandifer, Paul A. (1973) Larvae of the burrowing shrimp, Upogebia affinis, (Crustacea, Decapoda, Upogebiidae) from Virginia plankton, Chesapeake Science 14(2): 98-104

Sumner, Francis B.; Osburn, Raymond C.; Cole, Leon J.; Davis, Bradley M. (1913b) A biological survey of the waters of Woods Hole and vicinity Part II. Section III. A catalogue of the marine fauna Part II. Section IV. A catalogue of the marine flora, Bulletin of the Bureau of Fisheries 31: 539-860

U.S. National Museum of Natural History 2002-2021 Invertebrate Zoology Collections Database.

Williams, Austin B. (1984) Shrimps, Lobsters, and Crabs of the Atlantic Coast of the Eastern United States, Maine to Florida, Smithsonian Institution Press, Washington, DC. Pp. <missing location>

Williams, Austin B. (1993) Mud Shrimps, Upogebiidae, from the Western Atlantic (Crustacea: Decapoda: Thalassinidea), Smithsonian Contributions to Zoology 544: 1-77

Yale Peabody Museum of Natural History 2008-2016 YPM Invertebrate Zoology - Online Catalog. <missing URL>