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:


North American Invasion History:




Taxonomic Tree

Kingdom:   Animalia
Phylum:   Arthropoda
Subphylum:   Crustacea
Class:   Malacostraca
Subclass:   Eumalacostraca
Superorder:   Peracarida
Order:   Isopoda
Suborder:   Asellota
Superfamily:   Janiroidea
Family:   Munnidae
Genus:   Uromunna
Species:   reynoldsi


Munna (Uromunna) reynoldsi (Frankenberg and Menzies, 1966)

Potentially Misidentified Species

Uromunna hayesi

Uromunna sp. A San Francisco Bay
Uromunna sp. A (Munna) sp., introduced to the San Francisco Bay Delta (Cohen and Carlton 1995; Light et al. 2005; Graening et al. 2012) has not been described in detail, and could be conspecific with U. reyonoldsi.

Uromunna spec. Netherlands
Uromunna spec. Netherlands is a new introduction there. It is morphologically distinct from U. reynoldsi and U. hayesi, from the East and Gulf Coasts of North America (Faasse and Ligthart 2013).



Leaves, detritus, bacteria

Trophic Status:

Deposit Feeder



General HabitatNontidal FreshwaterNone
General HabitatTidal Fresh MarshNone
General HabitatUnstructured BottomNone
General HabitatCanalsNone
Salinity RangeLimnetic0-0.5 PSU
Salinity RangeOligohaline0.5-5 PSU
Salinity RangeMesohaline5-18 PSU
Tidal RangeSubtidalNone
Vertical HabitatEpibenthicNone

Tolerances and Life History Parameters

Minimum Temperature (ºC)13.4Field, Texas, Callahan et al. 1977
Maximum Temperature (ºC)34Field, Texas, Callahan et al. 1977
Minimum Salinity (‰)0Field, Schultz 1979
Maximum Salinity (‰)4.4Field, Callahan et al. 1977
Maximum Length (mm)1.6Frankenberg and Menzies 1966

General Impacts

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
CAR-VII Cape Hatteras to Mid-East Florida 0 Native Estab
CAR-I Northern Yucatan, Gulf of Mexico, Florida Straits, to Middle Eastern Florida 0 Native Estab
CAR-III None 1974 Def Estab
SEP-H None 1975 Def Estab
PAN_CAR Panama Caribbean Coast 1974 Def Unk
PAN_PAC Panama Pacific Coast 1975 Def Estab

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude


Cohen, Andrew N. (2006) Bridging divides: Maritime canals as invasion corridors., Springer, Dordrecht, Netherlands. Pp. 127-206

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>

Frankenberg, Dirk; Menzies, Robert J. (1966) A new species of asellote marine isopod Munna (Uromunna) reynoldsi (Crustacea: Isopoda), Bulletin of Marine Science of the Gulf and Caribbean 16(2): 200-208

Graening, G. O.; Rogers, D. Christopher (2013) Checklist of inland aquatic Isopoda (Crustacea: Malacostraca) of California, California Fish and Game 99(4): 176-192

Jones, M. L.; Rutzler, K. (1975) Invertebrates of the upper chamber, Gatun Locks, Panama Canal, with emphasis on Trochospongilla leidii (Porifera), Marine Biology 33: 57-66

Light, Theo; Grosholtz, Ted; Moyle, Peter (2005) Delta ecological survey (phase1): Nonindigenous aquatic species in the Sacramento-San Joaquin Delta, a literature review, In: None(Eds.) None. , Stockton, CA. Pp. <missing location>

Rasmussen, Paul W.; Wheeler, William E.; Moser, Timothy J,; Lawrence E. Vine, Sullivan, Brian D. ; Rusch, Donald H. (2001) Measurements of Canada Goose morphology: Sources of error and effects on cassification of subspecies, Journal of Wildlife Management 65: 716-725

Schultz, George A. (1979) Louisiana and Panama locations and ecology of Munna (Pangamunna nov. subgen.) reynoldsi (Isopoda: Asellota)., Proceedings of the Biological Society of Washington 9(3): 577-579

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