Americorophium sp.

Graening, G. O., Rogers, D. Christopher, Holsinger, John R., Barr, Cheryl & Bottorff, Richard, 2012, Checklist of Inland Aquatic Amphipoda (Crustacea: Malacostraca) of California, Zootaxa 3544, pp. 1-27 : 6-8

Americorophium sp.

Records: The following records are from the ABL database or this study.

Alameda Co. Alameda Cr. 2.8 mi. southeast of Dry Cr.; San Leandro Cr. Contra Costa Co. Alameda Cr., west Antioch Cr., Edwards Cr., Refugio Cr., San Pablo Cr., Wildcat Cr. Los Angeles Co. Ballona Cr. Marin Co. Novato Cr. above Redwood Blvd. Monterey Co. Salinas R., Carmel R. Sacramento Co. Lower American R. San Diego Co. Lower San Diego R., Santa Ysabel Cr. San Luis Obispo Co. Arroyo de la Cruz, Arroyo Grande, Chorro Cr., Pico Cr., Pismo Cr., San Luis Obispo R., San Simeon Cr., Santa Rosa Cr. San Mateo Co. San Francisquito Cr. 0.5 mi above Hwy 101; Gazos Cr. Lagoon at Hwy 1; San Gregorio USGS Gage. Santa Clara Co. Alviso Slough 0.5 mi below Hwy 237. Santa Cruz Co. Scott Cr. Lagoon at Hwy 1; Waddell Cr. and lagoon; Aptos Cr. at Spreckles Dr.; Pajaro R. Solano Co. Cordelia and Rockville. Ventura Co. Piru Cr., Calleguas Cr. Yolo Co. Sacramento R. at Sacramento State Park near Colusa.

Apocorophium louisianum Shoemaker, 1934 (euryhaline, exotic)

Records & Comments: This estuarine amphipod from the Gulf of Mexico was introduced to the Salton Sea (Riverside and Imperial Counties) probably when the Texas marine grass Diplanthera was intentionally introduced ( Barnard and Gray 1968, 1969; Bousfield and Hoover, 1997; Simpson et al. 1998).

Cheirimedeia macrocarpa Bulycheva, 1952 (estuarine)

Records & Comments: Occurs in estuaries along California and Oregon coasts; possibly introduced ( Myers and Lowry 2003; Chapman 2007).

Monocorophium acherusicum (Costa, 1857) (euryhaline, exotic)

Records: Carlton (1979) summarized its occurrence in most bays and estuaries of California, including Humboldt Bay, Bodega Harbor, Tomales Bay, Morro Bay, Port Hueneme, all bays and harbors of Los Angeles and Orange Co’s, San Diego Bay. CDWR reported it from San Pablo Bay, Grizzly Bay, Suisun Bay, Honker Bay, and the Sacramento R.

Comments: Native to the North Atlantic, but now cosmopolitan due to its ship fouling habit, this exotic species occurs in soft bottomed estuaries from Baja California to British Columbia ( Bousfield and Hoover 1997; Chapman 2007).

Monocorophium insidiosum (Crawford, 1937) (euryhaline, exotic)

Records: Carlton (1979) and Chapman (1988) summarized its sporadic occurrence in California, including Tomales Bay, Bolinas Lagoon, San Francisco Bay, Lake Merritt, Monterey Harbor, Elkhorn Slough, Santa Monica Bay, Long Beach Harbor, Alamitos Bay, and Newport Bay. CDWR reported it from San Pablo Bay, Grizzly Bay, Suisun Bay, and the Sacramento R.

Comments: Native to the North Atlantic, but now cosmopolitan due to ship fouling and oyster shipments, this species occurs in soft bottomed estuaries ( Bousfield and Hoover 1997; Chapman 1988, 2007). Chapman (2007) suggests that M. oaklandense ( Shoemaker, 1949) is a synonym.

Monocorophium uenoi (Stephensen, 1932) (euryhaline, exotic)

Records: This species is reported from estuaries and harbors from central California to Baja California ( Carlton 1979; Chapman 2007). Specific locales include Bodega Harbor, Tomales Bay, Bolinas Lagoon, San Pablo Bay, Sacramento R., Monterey Harbor, Elkhorn Slough, Morro Bay, Chorro Cr., Point Conception, Newport Bay ( Barnard 1952; Carlton 1979; CDWR database).

Comments: Native to the Sea of Japan and the South China Sea, it was apparently introduced with imported Japanese oysters and other fisheries products ( Chapman 1988; Bousfield and Hoover 1997).

Paracorophium sp. (euryhaline, exotic)

Records: San Luis Obispo Co. Cuesta-by-the-Sea, Sweet Springs, 83 specimens, July 2009, D.C. Rogers and M. Hill.

Comments: This genus is endemic to the southern hemisphere ( Barnard and Karaman 1991). However, an undetermined species has appeared in Humboldt Bay, Humboldt Co. ( Chapman 2007) and another in Tomales Bay, Marin Co. (J. Chapman, pers. comm.).

Sinocorophium alienense ( Chapman, 1988) (euryhaline, exotic)

Records & Comments: CDWR reported that 37,000 specimens were collected via ponar dredge from 1985 to 2010 from San Pablo Bay, Grizzly Bay, Suisun Bay, Sherman Lake, and Sacramento R., in Solano, Sonoma, Contra Costa, and Sacramento Co’s. Introduced to China and the USA during the Viet Nam War, S. alienense is reported from estuaries from Los Angeles Harbor, Tomales Bay, and from San Francisco Bay up through the Delta ( Chapman 1988, 2007; Bousfield and Hoover 1997).

Sinocorophium heteroceratum (Yu, 1938) (euryhaline, exotic)

Records & Comments: CDWR reported that 15,000 specimens were collected via ponar dredge from 1987 to 2010 from San Pablo Bay near the mouth of the Petaluma R. and from near Pinole Point, Grizzly Bay, Suisun Bay, and the lower Sacramento R. in Sacramento, Solano, and Sonoma Co’s. This invasive, exotic species is reported from Los Angeles Harbor and the San Francisco Bay and Delta regions ( Chapman 2007).