Invasion History

First Non-native North American Tidal Record: 1935
First Non-native West Coast Tidal Record: 1935
First Non-native East/Gulf Coast Tidal Record:

General Invasion History:


North American Invasion History:


Niambia capensis is a terrestrial isopod often found in littoral marine habitats near the edge of the high-tide line. It has a roughly ellipsoidal-rectangular body about 2.5 X as long as wide. It haswith a small oval head, which is wider than long. It has seven cephalothorax segments and a triangular abdomen of six segments. The last thoracic segment has its posterior angles drawn rearward. The eyes are on the sides of the head and the 2nd antennae are long, about one-quarter body length, with a 3-segmented flagellum. The pleotelson is triangular, slightly produced at the tipThe pleotelson tip reaches the base of the uropod peduncle tip. Uropods are short, compared to philoscioid isopods (eg. Littorophiloscia richardsonae, native to the West Coast, or Halophiloscia couchii, introduced on the East Coast, and Chile (Miller et al. 1936; Schultz et al. 1982; Brusca et al. 2007; Perez-Schultheiss et al. 2019). The color is variable, including white, brown, and red (Schultz et al. 1982). This isopod is one of many cultures and sold on the Web as reptile food. Because of the variable colors, it is sold as the 'Party Mix Isopod'.

A wide variety of introduced and native terrestrial isopods (sowbugs, woodlice, pillbugs) are found under stones, logs, and debris in moist habitats near water. Careful examination is needed to distinguish it from introduced (e.g., Porcellio laevis, P. scaber, P. dilatatus, Armadilloniscus vulgare) and native terrestrial isopods (Garthwaite et al 1992; Brusca et al. 2007). It does resemble members of the family Porcellionidae in lacking the ability of conglobation- it can't curl into a ball, as with true pill-bugs (Perez-Schultheiss et al. 2019).


Taxonomic Tree

Kingdom:   Animalia
Phylum:   Arthropoda
Subphylum:   Crustacea
Class:   Malacostraca
Subclass:   Eumalacostraca
Superorder:   Peracarida
Order:   Isopoda
Suborder:   Oniscidea
Infraorder:   Ligiamorpha
Family:   Platyarthridae
Genus:   Niambia
Species:   capensis


Metoponorthus capensis (Dollfus, 1895)
Niambia marginepapillosa (Budde-Lund, 1909)
Niambia pusilla ( Budde-Lund,, 1909)
Porcellio littorinus (Miller, 1936)
Mauritanicus littorinus (Schulz, 1983)

Potentially Misidentified Species



Niambia capensis is a terrestrial isopod often found in littoral marine habitats near the edge of the high-tide line. Sexes are separate, and development it direct, with brooded larvae (Miller 1936; Schultz et al. 1982). In its native South Africa, it was regarded as largely terrestrial, occurring up to 300 m altitude, but also occurring on sandy beaches (Barnard 1932). On South African sandy beaches, N. capensis was found on drying sand in the upper intertidal, but not in areas of resurgent waves. It coexisted with intrertidal amphipods (Talorchestia and isopods (Exocirrolana spp., Tylos spp. (Bally 1982). Introduced populations in California were found in rocks above the high-tide line, and in back-beach habitats, and occasionally in inland riparian areas (Miller 1936; Schultz et al. 1982; Garthwaite et al. 1992). Niambia capensis, like other upper-intertidal peracarids, feeds on salt-marsh leaf-litter and contributes to its degradation (Sprung and Machado 2000).



Trophic Status:

Deposit Feeder



General HabitatTerrestrialNone
General HabitatCoarse Woody DebrisNone
General HabitatUnstructured BottomNone
General HabitatSalt-brackish marshNone
General HabitatNontidal FreshwaterNone
Tidal RangeHigh IntertidalNone
Tidal RangeSupratidalNone
Vertical HabitatEpibenthicNone

Tolerances and Life History Parameters

Maximum Length (mm)8Barnard 1932
Broad Temperature RangeNoneWarm-Temperate
Broad Salinity RangeNoneLimnetic to Euhaline

General Impacts

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
WA-IV None 1895 Native Estab
P090 San Francisco Bay 1935 Def Estab
P058 _CDA_P058 (San Pedro Channel Islands) 2019 Def Estab
P070 Morro Bay 2019 Def Estab
P027 _CDA_P027 (Aliso-San Onofre) 1967 Def Estab
P065 _CDA_P065 (Santa Barbara Channel) 2014 Def Estab
P073 _CDA_P073 (Central Coastal) 2017 Def Estab
P020 San Diego Bay 1975 Def Estab
P056 _CDA_P056 (Los Angeles) 1978 Def Estab
P095 _CDA_P095 (Tomales-Drakes Bay) 1989 Def Estab
SEP-C None 2016 Def Estab

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude


Turner, Andrew D.; Fenwick, David; Powell, Andy; Dhanji-Rapkova, Monika; Ford, Charlotte; Hatfield, Robert G.; Santos, Andres; Martinez-Urtaza, Jaime; Bean. Tim P.; Baker-Austin, Craig : Stebbing, Paul (2018) New Invasive Nemertean Species (Cephalothrix simula) in England with High Levels of Tetrodotoxin and a Microbiome Linked to Toxin Metabolism, Marine Drugs 16(452): Published omline

Bañón, Rafael; Fariña, Juan; de Carlos, Alejandro (2023) New Data on Exotic Muricid Species (Neogastropoda: Muricidae) from Spain Based on Integrative Taxonomy, Diversity 15(1185): Published online d15121185

Brusca, Richard C.; Coeljo, Vania R. Taiti, Stefano (2007) The Light and Smith Manual: Intertidal invertebrates from Central California to Oregon (4th edition), University of Calfiornia Press, Berkeley CA. Pp. 503-542

Ferreira, Letícia; Seixas, M. Victor C.; Villalobos‑Guerrero, Tulio F.; Santos, Cinthya S. G. S (2024) Another candidate to human‑mediated transport: molecular evidence confirms that Alitta succinea (Nereididae: Annelida) is a widespread species, Marine Biodiversity 54(12): Published online

Marchessaux, Guillaume; Chevalier, Cristele; Mangano, Maria Cristina; Sara, Gianluca (2023) Larval connectivity of the invasive blue crabs Callinectes sapidus and Portunus segnis in the Mediterranean Sea: A step toward improved cross border management, Marine Pollution Bulletin 194(115272): Published online

Marquez, Federico M.; Zabala, Soledad; Bokenhans, Verena; Cumplido, Mariano; Espinosa, Free; Bigatti, Gregorio; Averbuj, Andres (2024) Predation of the invasive green crab Carcinus maenas on the edible snail Buccinastrum deforme, targeted as the most important nearshore marine gastropod fishery from Patagonia, Argentina, Regional Studies in Marine Science 69(103299): Published online

Metz, Sebastian; Itoïz, Sarah; Obio, Aleix; Derelle, Evelyne; Massana, Ramon; Berney, Cédric; de Vargas, Colomban; Soudant, Philippe; Monier, Adam; Chambouvet, Aurélie (2023) Global perspective of environmental distribution and diversity of Perkinsea (Alveolata) explored by a meta‑analysis of eDNA surveys, Scientific Reports 13(2011): Published online

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