Note

Table of Contents

List of All California Marine Isopods

Commonly encountered junior synonyms and generic reassignments are provided.

SUBORDER ANTHURIDAE Monod, 1922

• Family Antheluridae Poore and Lew Ton, 1988
  • Ananthura Barnard, 1925
    • Ananthura luna (Schultz, 1966). (formerly placed in Bathura) Southern CA (Coronado, Tanner and Santa Monica Canyons; Santa Monica Bay). 78-1298 m.
• Family Anthuridae Leach, 1814
  • Amakusanthura Nunomura, 1977
    • Amakusanthura californiensis (Schultz, 1964). (formerly placed in Apanthura). Southern CA to northwestern Mexico. 80 m.
  • Cyathura Norman and Stebbing, 1886
    • Cyathura munda Menzies, 1951. Marin County, CA to northwestern Baja California and Gulf of California. Low intertidal to 132 m. Common in kelp holdfasts (e.g. Egregia, Laminaria) and surfgrass (Phyllospadix).
  • Haliophasma Haswell, 1881
    • Haliophasma geminatum Menzies and Barnard, 1959. (formerly placed in Silophasma). Monterey, CA to central western Baja California. 9-512 m.
  • Mesanthura Barnard, 1914
    • Mesanthura occidentalis Menzies and Barnard, 1959. Point Conception, CA to Gulf of Nicoya, Costa Rica (including the Gulf of California). Intertidal to 20 m. On kelp and rocks.
• Family Paranthuridae Menzies and Glynn, 1968
  • Califanthura Schultz, 1977
    • Califanthura squamosissima (Menzies, 1951). (formerly placed in Colanthura). Dillon Beach, CA to Oaxaca, Mexico (including the Gulf of California). Shallow subtidal to 142 m. Muddy or sandy sediments and kelp beds.
  • Colanthura Richardson, 1902
    • Colanthura bruscai Poore, 1984. San Clemente, CA to Costa Rica. Intertidal to 27 m.
  • Paranthura Bate and Westwood, 1868. = Edanthura Boone, 1923.
    • Paranthura algicola Nunomura, 1978. A questionable species, not distinguishable from published descriptions; possibly P. elegans. Reported by Nunomura (1978) from California (no specific locality provided).
    • Paranthura elegans Menzies, 1951. Marin County, CA to northwestern Baja California, and throughout the Gulf of California. Intertidal to 55 m. On algal mats, mud bottoms, pier pilings, rocky low intertidal.
    • Paranthura linearis nomen nudum. (formerly placed in Edanthura.) Reported by Boone (1923) from Laguna Beach, CA.

SUBORDER ASELLOTA Latreille, 1803

• Family Asellidae Rafinesque, 1815
• Asellus Geoffroy, 1764
  • Asellus tomalensis Harford 1877. WA to central CA. Shallow, subtidal brachish water.

• Family Dendrottiidae Vanhöffen, 1914
  • Acanthomunna Beddard, 1886
• Acanthomunna tannerensis Schultz, 1966. Tanner Canyon, southern CA. Deep water.

• Family Desmosomatidae Sars, 1897
  • Momedossa Hessler, 1970
    • Momedossa symmetrica (Schultz, 1966). (formerly placed in Desmosoma). CA continental slope and submarine canyons. 469-2955 m.

• Family Janiridae Sars, 1897
  • Caecianiropsis Menzies and Pettit, 1956
    • Caecianiropsis psammophila Menzies and Pettit, 1956. Marin to Monterey County, CA. Intertidal. Buried in sand.
  • Caecijaera Menzies, 1951
    • Caecijaera horvathi Menzies, 1951. HI and southern CA. Intertidal. Living inside burrows excavated in wood by Limnoria species.
  • Iais Bovallius, 1886
    • Iais californica (Richardson, 1904). (formerly placed in Janiropsis). Humbolt County to San Diego County, CA, southeast Australia, New Zealand. Shallow water. Usually found in bays and estuaries, commensal with the wood-boring isopod Sphaeroma quoyanum.
  • Ianiropsis Sars, 1897
    • Ianiropsis analoga Menzies, 1952. WA to Marin County, CA. Intertidal. Under rocks or on Laminaria holdfasts. Leach (1814) described Janira maculosa from Europe; Hatch (1947) misidentified specimens from WA as J. maculosa (Menzies, 1952). The specimens Hatch misidentified where a new species that Menzies (1952) later described as Ianiropsis analoga. Carvacho’s (1981) distribution for J. maculosa (WA state) is based on Hatch (1947) and therefore incorrect.
    • Ianiropsis derjugini (Gurjanova, 1933). (formerly placed in Janiropsis). Komandorskie Islands, Bering Sea, to Monterey County, CA. Intertidal. Under rocks covered by algae.
    • Ianiropsis epilittoralis Menzies, 1952. Marin County to San Luis Obispo County, CA. Intertidal. On green filamentous algae in high intertidal.
    • Ianiropsis kincaidi (Richardson, 1904). (formerly placed in Janiropsis) Komandorskie Islands, Bering Sea, to Monterey County, CA. Intertidal. = Ianiropsis pugettensis Hatch, 1947.
    • Ianiropsis magnocula Menzies, 1952. San Juan Island, WA to 3 miles off Russian River, CA. 20-57 m. Muddy substrate and on red and brown algae.
    • Ianiropsis minuta Menzies, 1952. Marin County, CA. Intertidal. Under rocks or sand.
    • Ianiropsis montereyensis Menzies, 1952. Marin to Monterey Counties, CA. Intertidal to shallow subtidal. Under rocks or in Macrocystis holdfasts.
    • Ianiropsis tridens Menzies, 1952. San Juan Island, WA to Monterey County, CA; northern Chile. Intertidal. On algae; occasionally found in sponges.
  • Janiralata Menzies, 1951
    • Janiralata davisi Menzies, 1951. Monterey County, CA. Intertidal.
    • Janiralata occidentalis (Walker, 1898). (formerly placed in Janira). San Juan County, WA to Orange County, CA. Intertidal. Under rocks.
    • Janiralata rajata Menzies, 1951. Monterey County, CA. 40 m. A poorly known species reported from egg cases of the ray, Raja binoculata.
    • Janiralata solasteri (Hatch, 1947). (formerly placed in Janira). AK to southern CA. 50-90 m.
    • Janiralata triangulata (Richardson, 1899). (formerly placed in Ianthe). Monterey Bay, CA. Shallow water.

• Family Joeropsididae Nordenstam, 1933
• Joeropsis Koehler, 1885
  • Joeropsis concava (Schultz, 1966). (formerly placed in Jaeropsis). Central to southern CA, including San Diego. 60-221 m.
  • Joeropsis dubia dubia (Menzies, 1951). (formerly placed in Jaeropsis). Marin County, CA to San Quintín, Baja California and Gulf of California. Low intertidal to 100 m. Found on algal holdfasts, bryozoans, tunicates, hydroids, barnacles and under rocks.
  • Joeropsis dubia paucispinis (Menzies, 1951). (formerly placed in Jaeropsis). Marin County, CA. Intertidal to 116 m.
  • Joeropsis lobata (Richardson, 1899). (formerly placed in Jaeropsis). Monterey Bay, CA. Shallow water.

• Family Munnidae G. O. Sars, 1897
  • Munna Kroyer, 1839
    • Munna chromatocephala Menzies, 1952. Puget Sound, WA to central CA. Intertidal. Found on red algae and among incrusting organisms on rocks.
    • Munna halei Menzies, 1952. Tomales Bay to San Luis Obispo, CA. Intertidal. Found under rocks, in Macrocystis holdfast, and among spines of the purple sea urchin Strongylocentrotus purpuratus.
    • Munna magnifica Schultz, 1964. Off Santa Barbara, CA. 500m.
    • Munna spinifrons Menzies and Barnard, 1959. Point Conception (12 m) to Point Loma (145 m), CA.
    • Munna stephenseni Gurjanova, 1933. Bering Sea to central CA. Intertidal to 18 m.
  • Uromunna Menzies, 1962
    • Uromunna ubiquita (Menzies, 1952). (formerly placed in Munna). Puget Sound to northwestern Baja California and Gulf of California. Intertidal to shallow subtidal. = Munna minuta Hansen in Hatch, 1947.

• Family Munnopsidae Sars, 1869 (sensu lato Wilson, 1989)
  • Eurycope G. O. Sars, 1864
    • Eurycope californiensis Schultz, 1966. Santa Maria Basin to Newport Canyon, CA. 478-930 m.
  • Ilyarachna Sars, 1879
    • Ilyarachna acarina Menzies and Barnard, 1959. Southern CA (Santa Maria Basin to Point Loma). 73-1118 m.
    • Ilyarachna profunda Schultz, 1966. Southern CA (La Jolla Canyon). 461-1298 m.
  • Nannonisconus Schultz, 1966
    • Nannonisconus latipleonus Schultz, 1966. Central and southern CA. 465 m.

• Family Paramunnidae Vanhöffen, 1914
• Munnogonium George and Strömberg, 1968
  • Munnogonium erratum (Schultz, 1964). (formerly placed in Austrosignum). Santa Barbara Channel. 135 m.
  • Munnogonium tillerae (Menzies and Barnard, 1959). (formerly placed in Austrosignum). Central to southern CA. 5-150 m. = Munnogonium waldronensis George and Strömberg, 1968; = Munnogonium erratum (Schultz, 1964).
• Paramunna G. O. Sars, 1866
  • Paramunna quadratifrons Iverson and Wilson, 1981. Tanner Bank, southern CA. 197m.
• Pleurogonium G. O. Sars, 1863
  • Pleurogonium californiense Menzies, 1951. Throughout California, south at least to Point Loma. 90-154 m.

• Family Santiidae Kussakin, 1982
  • Santia Sivertsen and Holthuis, 1980
    • Santia hirsuta (Menzies, 1951). (formerly placed in Antias). Marin County, CA. Intertidal. Found in rock and sand between coralline and laminarian algal zones.

SUBORDER EPICARIDEA Latreille, 1831

• Family Bopyridae Rafinesque, 1815
• Aporobopyrus Nobili, 1906
  • Aporobopyrus muguensis Shiino, 1964. Bodega Bay, CA to central west Baja California. 10—12 m. In branchial chamber of porcelain crab Pachycheles rudis.
  • Aporobopyrus oviformis Shiino, 1934. Seto, Japan and Point Mugu, CA. 10—12 m. Found in branchial chamber of porcelain crab Pachycheles pubescens in CA.
• Argeia Dana, 1853
  • Argeia pugettensis Dana, 1853. Bering Sea to southern CA, Japan and Korea. Branchial parasites on shrimps of the family Crangonidae. 32-188 m. = Argeia pauperata Stimpson, 1857; = Argeia calmani Bonnier, 1900; = Argeia pingi Yu, 1935.
• Asymmetrione Codreanu, Codreanu and Pike, 1965
  • Asymmetrione ambodistorta Markham, 1985. Southern CA. 3 m. Infesting the hermit crab Isocheles pilosus.
• Bopyrella Bonnier, 1900
  • Bopyriscus calmani (Richardson, 1905). (formerly placed in Bopyrella). Southern and central CA. Intertidal to 9 m. On branchial chamber of the snapping shrimp Synalpheus lockingtoni and Alpheopsis equidactylus. = Bopyrella macginitiei Shiino, 1964.
• Ione Latreille, 1817
  • Ione cornuta Bate, 1864. British Columbia to San Francisco, CA. Intertidal to shallow water. In branchial chamber of species of ghost shrimps of the genus Callianassa (found on C. longimana in the eastern Pacific and C. japonica in the western Pacific). = Ione brevicauda Bonier, 1900.
• Munidion Hansen, 1897
  • Munidion pleuroncodis Markham, 1975. Central CA to (at least) central Mexico. Known to infest only the pelagic red galatheid Pleuroncodes planipes, which occurs in CA only during warm years when the host moves north from the tropical eastern Pacific. Offshore storms occasionally move P. planipes ashore where they are beached.
• Phyllodurus Stimpson, 1857
  • Phyllodurus abdominalis Stimpson, 1857. Southern British Columbia, Canada to northwest Baja California. Intertidal. Among pleopods of mud shrimp Upogebia pugettensis (female is posterior to first pair of large pleopods, male roves).
• Pseudione Kossmann, 1881
  • Pseudione galacanthae Hansen, 1897. British Columbia, Canada to Gulf of California. Offshore (> 50m). In branchial chamber of Galacantha diomediae parvispina and Munnida quadrispina.
• Schizobopyrina Markham, 1985
  • Schizobopyrina striata (Nierstrasz and Brender à Brandis, 1929). (formerly placed in Bopyrina). Throughout CA and Baja California, including Gulf of California. Shallow water. Found on Hippolytes californiensis (in San Diego Bay) and on Thor algicola (in Gulf of California).
• Stegophryxus Thompson, 1902
  • Stegophryxus hyphalus Markham, 1974. Carmel, CA to Baja California, Mexico. 69-319 m. Infesting Parapagurodes laurentae and P. makarovi.

• Family Dajidae Sars, 1899
  • Holophryxus Richardson, 1905
    • Holophryxus alaskensis Richardson, 1905. Behm Canal, AK, to Santa Barbara Channel, CA. 44-700 m. On dorsal part of carapace of Pasiphaea pacifica. = Holophryxus californiensis Richardson, 1908; = Hypodajus georgiensis Nierstrasz and Brend à Brandis, 1931.

• Family Entoniscidae Kossmann, 1882
• Portunion Giard and Bonnier, 1886
  • Portunion conformis Muscatine, 1956. San Francisco to Marin County. Intertidal. In visceral cavity of Hemigrapsus oregonensis and H. nudus.

• Family Liropsidae Bonnier, 1990
  • Cabirops Kossmann, 1884
    • Cabirops montereyensis Sassaman, 1985. Monterey Bay, CA. Shallow water. On marsupium of the isopod Aporobopyrus muguensi.
  • Faba Nierstrasz and Brender à Brandis, 1931
    • Faba setosa Nierstrasz and Brender à Brandis, 1931. Central CA. 300 m. On the shrimp, Spirontocaris bispinosa.
  • Hemioniscus Buchholz, 1866
    • Hemioniscus balani Buchholz, 1866. A European species apparently introduced throughout the world. In the eastern Pacific, reported from: British Columbia, Canada to Baja California, Mexico. Intertidal. On barnacles of the genus Balanus and Chthamalus. This species has also been assigned to Cryptothir, Cryptothiria, and Cryptoniscus.

SUBORDER FLABELLIFERA Sars, 1882

• Family Aegidae Dana, 1853
• Aega Leach, 1815
  • Aega (Aega) lecontii (Dana, 1854). (formerly placed in Aegacylla). Central and southern CA. Offshore. Taken from fish or from soft bottoms.
  • Aega (Rhamphion) microphthalma Dana, 1854. Monterey, CA. [species inquirenda; see Brusca, 1983A]
  • Aega (Rhamphion) plebia Hansen, 1897. Although no records exist for CA, this species is wide ranging, known from the Bering Strait to Peru and Tierra del Fuego. Only collected in deep water (688-2534 m) off oceanic islands. Taken from fish or from soft bottoms. = A. magnoculis Richardson, 1909.
  • Aega (Rhamphion) symmetrica Richardson, 1905. AK to central CA, possibly occurring in southern CA. 75 to 878 m. Taken from fish or from soft bottoms.
  • (Note: Pacific records of the Atlantic species Aega tenuipes are in error.)
• Rocinela Leach, 1815
  • Rocinela angustata Richardson, 1904. Bering Sea, AK to central western Baja California. 30-2214 m. Taken from fish or from soft bottoms.
  • Rocinela belliceps (Stimpson, 1864). (formerly placed in Aega). AK to Baja California, Clarion Island, and the Gulf of California (Mexico). Shallow subtidal to 284 m. Taken from fish or from soft bottoms. = Rocinela alascensis Richardson, 1898.
  • Rocinela laticauda Hansen, 1897. Rare. Known from only 2 records: Piedras Blancas Point (near San Simeon), CA and Acapulco (western Mexico). 120-906 m. Taken from fish or from soft bottoms.
  • Rocinela murilloi Brusca and Iverson, 1985. Point Sur, CA to Valparaiso, Chile. Very common at depths of 768 to 1866 m. Taken from fish or from soft bottoms.
  • Rocinela signata Schiödte and Meinert, 1879. Los Angeles, CA to Ecuador; also in tropical western Atlantic (Florida to Brazil). Intertidal to 68 m. Common. Taken from fish or from soft bottoms. = Rocinela aries Schiödte and Meinert, 1879.

• Family Anuropidae Stebbing, 1893
  • Anuropus Beddard, 1886
    • Anuropus bathypelagicus Menzies and Dow, 1958. CA. Pelagic; probably a symbiont on jellyfish and salps.

• Family Cirolanidae Dana, 1853
• Cirolana Leach, 1818
  • Cirolana diminuta Menzies, 1962. Point Conception, CA to western Baja California and Gulf of California; Galapagos Islands. Intertidal to 50 m. Easily confused with the tropical C. parva.
  • Cirolana harfordi (Lockington, 1877). (formerly placed in Aega). Vancouver Is (Canada) to northwestern Baja California; single record from La Paz (Baja California Sur). Also reported from the coasts of Russia, Japan and Australia, where it has apparently been introduced. Intertidal to shallow subtidal. C. harfordi var. spongicola Stafford, 1912 is probably C. diminuta.
• Eurydice Leach, 1815. = Branchuropus Moore, 1901; = Helleria Czerniavsky, 1868 (not Helleria Ebner, 1868); = Pelagonice Soika, 1955; = Slabberina Beneden, 1861.
  • Eurydice caudata Richardson, 1899. San Diego, CA to Gulf of Guayaquil (Ecuador), including all offshore islands of the tropical eastern Pacific. Intertidal to 160 m. = E. branchuropus Menzies and Barnard, 1959.
• Eurylana Jansen, 1981
  • Eurylana arcuata (Hale, 1925). (formerly placed in Cirolana). San Franscico, New Zealand, Australia and western coast of South America. Intertidal to shallow subtidal. Probably introduced from New Zealand. = Cirolana robusta Menzies, 1962; = Cirolana concinna Hale, 1925, in Menzies, 1962 (misidentification).
• Excirolana Richardson, 1912
  • Excirolana chiltoni (Richardson, 1905). (formerly placed in Cirolana). British Columbia to CA; Japan, Taiwan, Hong Kong. Intertidal. = E. kincaidi (Hatch, 1947); = E. vancouverensis (Fee, 1926); = E. japonica Richardson, 1912.
  • Excirolana linguifrons (Richardson, 1899). (formerly placed in Cirolana). Monterey Bay to southern CA. Intertidal.
• Metacirolana Kussakin, 1979
  • Metacirolana joanneae (Schultz, 1966). (formerly placed in Cirolana). Submarine canyons and basins off central and southern CA. 218 m.
• Natatolana Bruce, 1981
  • Natatolana californiensis (Schultz, 1966). (formerly placed in Cirolana). Throughout the canyons and basins of southern CA; Gulf of California, Costa Rica, Peru-Chile Trench. Fine sand and mud bottoms. 40-2000 m (most common at 800-1200 m). = Cirolana deminuta Menzies and George, 1972.

• Family Corallanidae Hansen, 1890
  • Excorallana Stebbing, 1904
    • Excorallana tricornis occidentalis Richardson, 1905. Southern CA to Panama. Intertidal to 138 m. On rocks, sandy beaches, and in mangrove habitats.
    • Excorallana truncata (Richardson, 1899). (formerly placed in Corallana). Point Conception, CA to Galapagos Islands. Intertidal to 183 m. = E. kathyae Menzies, 1962.

• Family Cymothoidae Leach, 1818
• Ceratothoa Dana, 1853
  • Ceratothoa gaudichaudii (H. Milne Edwards, 1840). (formerly placed in Cymothoa). Southern CA to Cape Horn, and around to southern Patagonia. Rare in southern CA. Found on many species of pelagic fishes.
  • Ceratothoa gilberti (Richardson, 1904). (formerly placed in Meinertia). Southern CA to Mazatlán, Sinaloa, Mexico. Rare in southern CA; a tropical species. In the mouths of mullet (Mugil cephalus and M. hospes).
• Elthusa Bruce, 1990
  • Ethusa californica (Schioedte and Meinert, 1884). (formerly placed in Livoneca). Los Angeles, CA to Peru. Found on dwarf surfperch (Micrometrus minimus), shiner surfperch (Cymatogaster aggregata), surf smelt (Hypomesus preitiosus), topsmelt (Atherinops affinis), arrow goby (Clevelandia ios) and California killifish (Fundulus parvipinnis).
  • Elthusa vulgaris (Stimpson, 1857). (formerly placed in Livoneca). Coos Bay, OR to Colombia; common from southern CA and Gulf of California to Costa Rica. 1 — 311 m. Found in gill chambers of a wide variety of fishes.
• Enispa Bruce, 1990
  • Enispa convexa (Richardson, 1905). (formerly placed in Livoneca). San Diego, CA to Gulf of Guayaquil, Equador. Rare in CA; a tropical species. Found in gill chambers of Pacific bumper (Chloroscombrus orqueta), pompanos (Trachinotus rhodopus or T. paitensis) and Serranus sp.
• Mothocya Costa in Hope, 1851
  • Mothocya rosea Bruce, 1986. San Diego to Central America. Found in species of Hyporhampus (H. rosea and H. snyderi).
• Nerocila Leach, 1818
  • Nerocila acuminata Schioedte and Meinert, 1881. Southern CA to Peru, including Gulf of California, HI, Las Tres Marías and Galapagos Islands. Parasite of many fish species. = Nerocila californica Schioedte and Meinert, 1881; Pterisopodus bartschi Boone, 1918.
• (Note: records of Anilocra from the E. Pacific are probably erroneous.)

• Family Limnoriidae White, 1850
  • Limnoria Leach, 1814
    • Limnoria algarum Menzies, 1957. OR to southern CA. Intertidal to 15 m. On holdfasts of Macrocystis, Egregia, Laminaria, Postelsia, Nereocystis, Sargassum and Pelagophycus.
    • Limnoria lignorum (Rathke, 1799). (formerly placed in Cymothoa). Temperate and boreal Northern Hemisphere distribution, it occurs from Kodiak Island, AK to Point Arena, CA in the Pacific coast. Intertidal to 20 m. Wood borer. = Limnoria terebrans Leach, 1813.
    • Limnoria quadripunctata Holthuis, 1949. Widespread cool temperate distribution; in CA it occurs from central to southern CA. Intertidal to 30 m. Wood borer.
    • Limnoria tripunctata Menzies, 1951. From various temperate and tropical locations, including the Caribbean; on the Pacific coast it occurs from San Francisco, CA to Mazatlán, Mexico. Intertidal to 7 m. Wood borer.

• Family Serolidae Leach, 1814
  • Heteroserolis Nordenstam, 1933
    • Heteroserolis carinata (Lockington, 1877). (formerly placed in Serolis). Southern CA to Baja California, and into the Gulf of California. Intertidal to 98 m. On soft bottoms.

• Family Sphaeromatidae H. Milne Edwards, 1840
  • Ancinus H. Milne Edwards, 1840
    • Ancinus granulatus Holmes and Gay, 1909. Southern CA, from Santa Barbara to Mazatlán (Mexico), and throughout Gulf of California. Intertidal to 10 m. = A. seticomvus Trask, 1970. Ancinus and Bathycopea are placed in the family Ancinidae by Bruce (1993) and some other workers.
  • Bathycopea
    • Bathycopea daltonae (Menzies and Barnard, 1959). (formerly in Ancinus). Monterey Bay to San Miguel Islands, CA. 19-20 m.
  • Clianella Boone, 1923
    • Clianella elegans Boone, 1923. Nomen dubium. La Jolla and San Pedro, CA.
  • Discerceis Richardson, 1906
    • Discerceis granulosa (Richardson, 1899). (formerly placed in Cilicaea) Southern CA to Cedros Island, Baja California. Subtidal, to 37 m.
  • Dynamene Leach, 1814
    • Dynamene tuberculosa Richardson, 1899. Aleutian Islands, AK to southern CA. Shallow water.
  • Dynamenella Hansen, 1905
    • Dynamenella benedicti (Richardson, 1899). (formerly placed in Dynamene). Monterey Bay, CA. Intertidal.
    • Dynamenella conica Boone, 1923. San Francisco to Monterey Bay. Intertidal. [species inquirenda]
    • Dynamenella dilatata (Richardson, 1899). (formerly placed in Dynamene). Monterey Bay, CA. Intertidal.
    • Dynamenella glabra (Richardson, 1899). (formerly placed in Dynamene). OR to San Diego, CA. Intertidal.
    • Dynamenella sheareri (Hatch, 1947). (formerly placed in Dynamene). San Juan Arquipelago, WA to southern CA. Intertidal to shallow subtidal.
  • Exosphaeroma Stebbing, 1900
    • Exosphaeroma amplicauda (Stimpson, 1857). (formerly placed in Sphaeroma). AK to Los Angeles, CA. Intertidal.
    • Exosphaeroma aphrodita Boone, 1923. Nomen dubium. La Jolla, CA.
    • Exosphaeroma inornata Dow, 1958. Northern CA to Los Angeles. Intertidal and shallow subtidal. In holdfasts of kelp (Macrocystis). = E. media George and Strömberg, 1968.
    • Exosphaeroma octoncum (Richardson, 1897). (formerly placed in Sphaeroma). Monterey to Marin County, CA. Shallow water.
    • Exosphaeroma rhomburum (Richardson, 1899). (formerly placed in Sphaeroma). Monterey Bay, CA. Shallow water.
  • Gnorimosphaeroma Menzies, 1954
    • Gnorimosphaeroma insulare (Van Name, 1940). (formerly placed in Exosphaeroma). Popof Island, AK to San Nicolas Island, off Los Angeles, CA. Fresh and brackish water. In shallow estuaries and lagoons along the coast. = G. oregonensis lutea Menzies, 1954; = G . lutea Menzies, 1954.
    • Gnorimosphaeroma noblei Menzies, 1954. Central CA. High intertidal. Under rocks.
    • Gnorimosphaeroma oregonense (Dana, 1853). (formerly placed in Sphaeroma). AK to San Francisco Bay, CA. Intertidal to 24 m. Brackish to salt water.
    • Gnorimosphaeroma rayi Hoestlandt, 1969. Japan, Eastern Siberia, HI and Tomales Bay, CA. Shallow water. Probably introduced to CA together with Japanese oysters (implanted at Tomales Bay).
  • Paracerceis Hansen, 1905. = Sergiella Pires, 1980.
    • Paracerceis cordata (Richardson, 1899). (formerly placed in Cilicaea). Aleutian Islands to southern CA. Intertidal to shallow subtidal.
    • Paracerceis gilliana (Richardson, 1899). (formerly placed in Cilicaea). Catalina Island, CA. 55-73 m.
    • Paracerceis sculpta (Holmes, 1904). (formerly placed in Dynamene). Southern CA (San Clemente Island and San Diego) to Gulf of California and Michoacan (Mexico). Widely introduced around the world by oceanic shipping (e.g., Brazil, Hawaii, Atlantic coast of Europe, Mediterranean, Australia). Intertidal to shallow subtidal. Males with harems occurring in calcareous sponges.
  • Paradella dianae (Menzies, 1962). (formerly placed in the genera Dynamenopsis and Dynamenella). Southern CA to Bahía de San Quintín, Baja California. Intertidal to shallow subtidal.
  • Sphaeroma Latreille, 1802
    • Sphaeroma quoyanum H. Milne Edwards, 1840. San Diego County to Humbolt County, CA; Australia; New Zealand. Intertidal to shallow subtidal. Wood, mud and soft rock borer. Probably introduced to western North America in the late 1800’s on ships from Australia (see Rotramel, 1972; Carlton, 1979; Carlton and Iverson, 1981). = S. pentodon Richardson, 1904.
    • Sphaeroma walkeri Stebbing, 1905. A western Pacific and Indian Ocean species introduced to southern CA. According to Kensley and Schotte (1989), this is possibly a pantropical species (it also occurs in the Caribbean).
  • Tecticeps Richardson, 1897
    • Tecticeps convexus Richardson, 1899. OR border to Point Conception, CA. 9 m. Placed in the family Tecticipididae by Iverson (1982), Bruce (1993), and some other workers.

• Family Tridentellidae, Bruce 1984
  • Tridentella Richardson, 1905. = Smicrostoma Hale, 1925.
• Tridentella glutacantha Delaney and Brusca, 1985. Farallon Islands to southern CA. 128-360 m. Rocky bottoms.
• Tridentella quinicornis Delaney and Brusca, 1985. Southern CA Channel Islands. 53 m. Rocky bottoms.

SUBORDER GNATHIIDEA Hansen, 1916

• Family Gnathiidae Harger, 1880
• Caecognathia Dollfus, 1901
  • Caecognathia crenulatifrons (Monod, 1926). (formerly placed in Gnathia). On southern CA coastal shelf and slope, 9-1376 m; off Santa Cruz Island, 80-270 m; Santa Cruz Basin. Northern record is south of Monterey Bay, CA; southernmost record is off Punta Banderas (northern Baja California, Mexico).
  • Caecognathia sanctaecrucis (Schultz, 1972). (formerly placed in Gnathia). Santa Maria Basin, Santa Cruz Canyon, Southern CA Bight. 218 m. = G. hirsuta Schultz, 1966; not G. hirsutus of G.O. Sars 1870.
• Gnathia Leach, 1814
  • Gnathia clementensis Schultz, 1966. Known only from the type locality, San Clemente Canyon, CA. 162 m.
  • Gnathia coronadoensis Schultz, 1966. Known only from two specimens collected in Coronado Canyon. 344-812 m. In green mud and green mud with hydrogen sulfide.
  • Gnathia productatridens Menzies and Barnard, 1959. Point Conception to the Southern CA Bight. 20-164 m.
  • Gnathia steveni Menzies, 1962. Redondo Beach, CA, to northwestern Baja California. Intertidal.
  • Gnathia tridens Menzies and Barnard, 1959. Point Conception and San Clemente, 11-27 m. One record from Gulf of Alaska.
  • Gnathia trilobata Schultz, 1966. Coronado Canyon (812 m), La Jolla Canyon (976 m), and off Point Loma (98-153 m).

SUBORDER MICROCERBERIDEA Lang, 1960

• Family Microcerberidae Karaman, 1933
• Coxicerberus Wägele, Voelz and MacArthur, 1995
  • Coxicerberus abbotti (Lang, 1960). (formerly placed in Microcerberus). Central CA. Interstitial; intertidal.

SUBORDER VALVIFERA Sars, 1882

• Family Arcturidae Bate and Westwood, 1868
• Idarcturus Barnard, 1914
  • Idarcturus allelomorphus Menzies and Barnard, 1959. Monterey to Point Loma, including Cortes and Tanner Banks. Mud bottoms. 12-92 m.
  • Idarcturus hedgpethi Menzies, 1951. Tomales Bay, CA. Low intertidal. On seaweeds and hydroids.
• Microarcturus Nordenstam, 1933
  • Microarcturus tannerensis Schultz, 1966. Tanner Canyon, southern CA. 1298 m.
• Neastacilla Tattersall, 1921
  • Neastacilla californica (Boone, 1918). (formerly placed in Astacilla). Point Conception to Point Loma, CA, and isolated reports from the Gulf of California. Shallow water to 99 m. On seaweed.

• Family Chaetiliidae Dana, 1853
  • Mesidotea Richardson, 1905. = Saduria Adams in White, 1852.
    • Mesidotea entomon (Linnaeus, 1767). (formerly placed in Oniscus). Circumpolar, western coast of North America to Pacific Grove, CA; Stockholm, Germany, Labrador, Kara Sea. Intertidal in the northern part of its range, to 30 m in the south.

• Family Holognathidae Thomson, 1904
  • Cleantioides Kensley and Kaufman, 1978
    • Cleantioides occidentalis (Richardson, 1899). (formerly placed in Cleantis). Southern CA to Ecuador and Galapagos Islands. Intertidal to 50 m.

• Family Idoteidae Fabricius, 1798
  • Colidotea Richardson, 1899
    • Colidotea findleyi Brusca and Wallerstein, 1977. San Diego (rare) to northwestern Baja California, with records from the northern Gulf of California. Intertidal to a depth of at least 1 m. Common on the brown algae Sargassum.
    • Colidotea rostrata (Benedict, 1898). (formerly placed in Idotea). Northern CA (rare) to northwest coast of Baja California (Mexico). Intertidal. Commensal of sea urchin Strongylocentrotus.
  • Edotia Guerin-Meneville, 1844
    • Edotia sublittoralis Menzies and Barnard, 1959. Vancouver Island (British Columbia) to northwestern Baja California (Mexico); one record from Costa Rica. 15 to 46 m.
  • Erichsonella Richardson, 1900
    • Erichsonella crenulata Menzies, 1950. Southern CA (Orange County, CA). Intertidal to shallow subtidal. On eelgrass, Zostera.
    • Erichsonella pseudoculata Boone, 1923. Point Conception, CA to the Mexican border. Intertidal to 18 m.
  • Idotea Fabricius, 1799 (some researchers distinguish two genera within Idotea, Idotea sensu stricto and Pentidotea)
    • Idotea aculeata (Stafford, 1913). (formerly placed in Pentidotea). Northwestern Canada to western coast of Baja California; scattered records from Gulf of California. Intertidal.
    • Idotea fewkesi Richardson, 1905. AK to southern CA. Shallow water.
    • Idotea kirchanskii Miller and Lee, 1970. OR to southern CA. Intertidal. On surfgrass, Phyllospadix.
    • Idotea metallica Bosc, 1802. A rare tropical species occasionally occurring in southern CA and Gulf of California during warm years; pelagic, attached to floating seaweed. Cosmotropical.
    • Idotea montereyensis (Maloney, 1933). (formerly placed in Pentidotea). Northwestern Canada to northwestern Baja California. Intertidal. Common on surfgrass Phyllospadix. = Idotea gracillima (Dana) of Richardson, 1905 and Schultz, 1969.
    • Idotea ochotensis Brandt, 1851. AK to northern CA. Intertidal to 36 m.
    • Idotea resecata Stimpson, 1857. AK to southwest Baja California (Mexico). Intertidal. Frequently found living in kelp (e.g., Macrocystis, Egregia) and eelgrass (Zostera).
    • Idotea rufescens Fee, 1926. British Columbia to central western Baja California. Intertidal to 82 m. On algae. Possibly a synonym of I. resecata.
    • Idotea schmitti (Menzies, 1950). (formerly placed in Pentidotea). Northwestern Canada to northwestern Baja California. Intertidal to shallow subtidal. = Pentidotea whitei Stimpson of Richardson, 1905.
    • Idotea stenops Benedict, 1898. AK to western Baja California; one record from the Gulf of California. Intertidal to shallow subtidal.
    • Idotea urotoma Stimpson, 1864. AK to western Baja California; scattered records from southern Gulf of California. Intertidal to shallow subtidal. = Cleantis heathii Richardson, 1899; = Idotea rectilinea Lockington, 1877.
    • Idotea wosnesenskii Brandt, 1851. AK to San Francisco; one anomolous record from La Paz (Baja California). Intertidal to shallow subtidal. = Idotea hirtipes Dana, 1853; = Idotea oregonensis Dana, 1853.
  • Synidotea Harger, 1878
    • Synidotea angulata Benedict, 1897. British Columbia to northern CA. 60- 76 m.
    • Synidotea berolzheimeri Menzies and Miller, 1972. Central CA, San Luis Obispo to Sonoma County. Intertidal. On hydroid, Aglaophenia.
    • Synidotea calcarea Schultz, 1966. Tanner and Santa Rosa Canyons. 54-813 m.
    • Synidotea consolidata (Stimpson, 1856). (formerly placed in Idotea). Southern AK to central CA. Intertidal to 20 m. This species has been confused (in the literature) with the very similar circum-Arctic Synidotea bicuspida (Owen, 1839). = Synidotea macginitiei Maloney, 1933.
    • Synidotea harfordi Benedict, 1897. OR to southwestern Baja California; rare in Gulf of California; one record from Costa Rica. Introduced to Japan. Intertidal to shallow subtidal. Easily confused with S. laticauda; see Poore 1996 for distinctions.
    • Synidotea laticauda Benedict, 1897. San Francisco, CA. Shallow water; often found on floats in bays and estuaries. See Poore 1996 for diagnostic and biogeographic information.
    • Synidotea magnifica Menzies and Barnard, 1959. San Luis Obispo to northwestern Baja California (Mexico). 29 to 98 m.
    • Synidotea media Iverson, 1972. Point Soberanes to Santa Maria Basin, CA. 183 m.
    • Synidotea pettiboneae Hatch, 1947. British Columbia to central CA. Intertidal. On hydroids and bryozoans.
    • Synidotea ritteri Richardson, 1904. British Columbia to north of San Francisco. Intertidal.
  • Synisoma Collinge, 1917
    • Synisoma wetzerae Ormsby, 199l. One record from Catalina Island, southern CA (on rocks and brown algae, Sargassum palmeri and Cystoseira neglecta) and one record from Guayamas (Gulf of California). 13 m.

SUBORDER ONISCIDEA Latreille, 1829

• Family Armadillidae Brandt and Ratzeburg, 1831
• Cubaris Brandt, 1833
  • Cubaris affinis (Dana, 1854). Nomen dubium. (formerly placed in Spherillo). California. This and the following species, which according to Budde-Lund (1904) are synonyms, are not included in the key since their original descriptions do not permit species recognition and type specimens are lost. Most probably they belong to the genus Venezillo.
  • Cubaris californica (Budde-Lund, 1885). Nomen dubium. (formerly placed in Armadillo). San Francisco and San Pedro, CA. = Armadillo speciosus Stuxberg, 1875, nomen praeoccupatum.
• Venezillo Verhoeff, 1928
  • Venezillo microphthalmus (Arcangeli, 1932). (formerly placed in Armadillo). Southern and central CA.

• Family Armadillidiidae Brandt and Ratzeburg, 1831
  • Armadillidium Brandt, 1833
    • Armadillidium vulgare (Latreille, 1804). (formerly placed in Armadillo). Cosmopolitan species of Mediterranean origin.

• Family Ligiidae Brandt and Ratzeburg, 1831
  • Ligia Fabricius, 1798
    • Ligia occidentalis Dana, 1853. Oregon to Gulf of California, Mexico. Rocky shores.
    • Ligia pallasii Brandt, 1833. AK to Santa Cruz, CA. Rocky shores on open coast environments.
  • Ligidium Brandt, 1833
    • Ligidium gracile (Dana, 1856). (formerly placed in Styloniscus). AK to CA. Riparian.
    • Ligidium latum Jackson, 1923. San Francisco Bay Area to Santa Barbara County, CA. Riparian.

• Family Philosciidae Kinahan, 1857
• Littorophiloscia Hatch, 1947
  • Littorophiloscia richardsonae (Holmes and Gay, 1909). (formerly placed in Philoscia). Vancouver Island, Canada to Baja California, Mexico. Littoral species common in marshes, along bays and estuaries.
• Family Platyarthridae Verhoeff, 1949
  • Niambia Budde-Lund, 1908
    • Niambia capensis (Dollfus, 1895). (formerly placed in Metoponorthus). Introduced from southern Africa; widespread along the Pacific coast from southern WA to southern CA. Supralittoral and riparian. = Porcellio littorina Miller, 1936.
  • Platyarthrus Brandt, 1833
    • Platyarthrus aiasensis Legrand, 1953. This species has a western Mediterranean-Atlantic distribution; introduced to USA (known from southern CA and TX). A myrmecophile.

• Family Porcellionidae Brandt and Ratzeburg, 1831
  • Porcellio Latreille, 1804
    • Porcellio dilatatus Brandt, 1833. Introduced from Europe. = Porcellio spinicornis occidentalis Miller, 1936.
    • Porcellio laevis Latreille, 1804. A cosmopolitan species of Mediterranean origin. Synanthropic.
    • Porcellio scaber Latreille, 1804. A cosmopolitan species of European origin. = Porcellio scaber americanus Arcangeli, 1932.
• Porcellionides Miers, 1877
  • Porcellionides floria Garthwaite and Sassaman, 1985. Southern and western USA, Yucatan Peninsula (Caribbean Mexico), Baja California (Mexico), and Bahamas. This species is very similar to the cosmopolitan synanthropic Porcellionides pruinosus (Brandt, 1833), which is present in the USA but does not seem to occur on the Pacific coast (Garthwaite and Sassaman, 1985).

• Family Scyphacidae Dana, 1852
  • Alloniscus Dana, 1856
    • Alloniscus mirabilis (Stuxberg, 1875). (formerly placed in Rhinoryctes). From San Mateo County, CA to Magdalena Bay, Baja California, Mexico. A littoral halophilic species common on sandy beaches above high tide line, where it borrows in sand under driftwood. = Alloniscus cornutus Budde-Lund, 1885.
    • Alloniscus perconvexus Dana, 1856. WA to west Baja California. A littoral halophilic species common on sandy beaches above high tide line, where it borrows in sand under driftwood.
  • Armadilloniscus Uljanin, 1875
    • Armadilloniscus coronacapitalis Menzies, 1950. Marin County to San Miguel and Anacapa Islands, CA. A littoral halophilic species.
    • Armadilloniscus holmesi Arcangeli, 1933. British Columbia to west Baja California, Mexico. A littoral halophilic species found in marshes, bays and estuaries under rocks and driftwood. = Actoniscus tuberculatus Holmes and Gay, 1909, nomen praeoccupatum.
    • Armadilloniscus lindahli (Richardson, 1905). (formerly placed in Actoniscus). Marin County, CA to Baja California, Mexico. A littoral halophilic species.
  • Detonella Lohmander, 1927
    • Detonella papillicornis (Richardson, 1904). (formerly placed in Trichoniscus). Pacific coast, from Bering Island (Russia) and Alaska to San Francisco Bay, CA. A littoral halophilic species common under rocks above high tide line.

• Family Trichoniscidae Sars, 1899
• Brackenridgia Ulrich, 1902
  • Brackenridgia heroldi (Arcangeli, 1932). (formerly placed in Protrichoniscus). Central and southern CA.
• Haplophthalmus Schoebl, 1861
  • Haplophthalmus danicus Budde-Lund, 1885. A cosmopolitan species.

• Family Tylidae Milne Edwards, 1840
• Tylos Audouin, 1826
  • Tylos punctatus Holmes and Gay, 1909. Southern CA to Baja California and the Gulf of California. A littoral halophilic species restricted to sandy beaches where it burrows above the most recent high tide line during the day and is active on surface at night (Hays, 1977).