Invasion History

First Non-native North American Tidal Record: 1988
First Non-native West Coast Tidal Record: 1988
First Non-native East/Gulf Coast Tidal Record:

General Invasion History:

Although Eochelidium sp. A has not been identified to species, it belongs to a genus known only from the Western Pacific. It most closely resembles E. miraculum Imbach 1967, described from the South China Sea and E. carinorostrum Jo 1990, described from Korea (Paquette and Cadien 1996; Chapman 2007). It was first reported from Long Beach Harbor, California (CA) in the 1980s, and later found in San Francisco Bay, CA (1st record 1993) and Puget Sound, Washington (1st record 1997) (Cohen and Carlton 1995; Paquette and Cadien 1996; Cohen et al. 1998).

North American Invasion History:

Invasion History on the West Coast:

Eochelidium sp. A was first collected in the channel of Long Beach Harbor in the late 1980s (Paquette and Cadien 1996). It was subsequently found in 1998 in Alamitos Bay and Newport Bay (Ranasinghe et al. 2005). In a 2011 survey it was collected in Huntington Harbor and Dana Point Harbor (1 specimen) (California Department of Fish and Wildlife 2014). A few specimens were collected in San Francisco Bay in the 1990s (Cohen and Carlton 1995), and by 2005, it was found to be established in the Central and South Bays (Foss 2009). Eochelidium sp. A was first collected in Puget Sound in 1997 (Cohen et al. 1998) and is apparently established, although we have found no information on its distribution in the Sound. Because this amphipod is known primarily from infaunal communities, ballast water is considered the likeliest means of introduction (Paquette and Cadien 1996), but it has also been collected in epifaunal communities (California Fish and Wildlife 2014).


Description

Eochelidium sp. A does not match any known species, but is similar to E. miraculum Imbach 1967, described from the Gulf of Thailand, and E. carinorostrum Jo 1990, described from Korea (Paquette and Cadien 1996). Among distinctive features of the family Oedicerotidae are: having the two eyes merged into a single mass on the rostrum; the lack of an accessory flagellum on Antenna 1; having perieopods weakly adapted for digging; having an exceptionally long pereiopod 7, and having a smoothly-rounded, shield-like telson (Chapman 2007). Paquette and Cadien (1996) list features separating E. sp. A from seven described species of Eochelidium.

The head has a change in slope just behind the eye and the junction of the head and body is distinct. The rostrum does not extend beyond the first segment of the peduncle of Antenna 1 and points downward with a strong ventral keel. Antenna 1 is roughly equal to the peduncle of Antenna 2. Segments 1 and 2 of antenna 1 are roughly equal. Gnathopod 1 is much shorter than Gnathopod 2, but the propodus (segment 6) of Gnathopod 1 is greatly inflated, and has a prominent dactyl, equal in length to the posterior margin of the propodus. Gnathopod 2 is longer, but less robust, with a small propodus and dactyl, forming a fully closing claw. The dactyl is about 1/4 of the propodus' length. The posterior-ventral edge of Coxa 3 is beveled, and Coxa 5 is as long as it is wide. The dactyls are roughly equal to segments 5 for pereiopods 3 and 4. For pereiopods 5 and 6, segments 6 are about 2X as long as segment 5. The posterior edges of pereiopods 3-5 are densely covered with setae. Uropods 1 and 2 have outer rami slightly shorter than the inner ones. The inner margin of the inner rami have spines (two spines on U1, one on U2). Eochelidium sp. A is about 5 mm long, and its body is pale, mottled with dark pigment. Description based on: Paquette and Cadien 1996 and Chapman 2007.


Taxonomy

Taxonomic Tree

Kingdom:   Animalia
Phylum:   Arthropoda
Subphylum:   Crustacea
Class:   Malacostraca
Subclass:   Eumalacostraca
Superorder:   Peracarida
Order:   Amphipoda
Suborder:   Gammaridea
Family:   Oedicerotidae
Genus:   Eochelidium
Species:   sp. A

Synonyms

Synchelidium cf. miraculum (None, None)
Eochelidium cf. miraculum (None, None)

Potentially Misidentified Species

Eochelidium lenorostralum
Paquette and Cadien (1996) list features distinguishing Eochelidium sp. A. from each of the listed Western Pacific species, below:

Eochelidium bulytschevae
None

Eochelidium carinorostrum
None

Eochelidium miraculum
None

Eochelidium nonmiraculum
None

Eochelidium nonrostrum
None

Eochelidium rostriospiculum
None

Ecology

General:

Eochelidium sp. A is a free-living marine gammarid amphipod, occurring over sand and silty bottoms, and around marinas and docks. Sexes are separate, the young are brooded, and development is direct (Bousfield 1973). Little is known of the life history or biology of this untdentified amphipod. It occurs over sandy and silty bottoms, and also burrows into them (Paquette and Cadien 1996; Ranasinghe et al. 2005: Chapman 2007).

Trophic Status:

Omnivore

Omni

Habitats

General HabitatUnstructured BottomNone
General HabitatMarinas & DocksNone
Salinity RangePolyhaline18-30 PSU
Salinity RangeEuhaline30-40 PSU
Tidal RangeSubtidalNone
Vertical HabitatEpibenthicNone


Tolerances and Life History Parameters

Maximum Length (mm)5Imbach 1967; Chapman 2007
Broad Temperature RangeNoneCold temperate-Warm temperate
Broad Salinity RangeNonePolyhaline-Euhaline

General Impacts

No impacts have been reported for introduced populations of Eochelidium sp. A.

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
P027 _CDA_P027 (Aliso-San Onofre) 2011 Non-native Unknown
P040 Newport Bay 1998 Non-native Established
NEP-V Northern California to Mid Channel Islands 1995 Non-native Established
P050 San Pedro Bay 1993 Non-native Established
P090 San Francisco Bay 1993 Non-native Established
NEP-VI Pt. Conception to Southern Baja California 1988 Non-native Established

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude
755499 ISS 2000-2002 Survey Data 2000 2000-09-13 Port Hueneme Infaunal 02 Non-native 34.1531 -119.2101
755500 ISS 2000-2002 Survey Data 2001 2001-07-11 LA Harbor Plankton 01 Non-native 33.7323 -118.2294
755501 ISS 2000-2002 Survey Data 2001 2001-10-09 San Diego Bay Plankton 01 Non-native 32.6932 -117.2306
755502 ISS 2000-2002 Survey Data 2001 2001-10-09 San Diego Bay Plankton 05 Non-native 32.6706 -117.1285
755503 ISS 2000-2002 Survey Data 2001 2001-10-11 LA Harbor Plankton 01 Non-native 33.7323 -118.2294
755504 Introduced Species Study 2005 2005-06-08 Sea Plane Lagoon Non-native 37.7761 -122.2998
755505 Introduced Species Study 2005 2005-06-09 Richardson Bay Non-native 37.8588 -122.4798
755506 Introduced Species Study 2005 2005-09-07 Redwood Creek - Marina Non-native 37.5021 -122.2130
755507 Introduced Species Study 2005 2005-09-07 Redwood Creek - Shipping Non-native 37.5120 -122.2109
755508 Introduced Species Study 2005 2005-10-06 Santa Fe Channel - Front Non-native 37.9101 -122.3644
755509 Introduced Species Study 2010 2010-05-31 Redwood Creek - Marina Non-native 37.5021 -122.2130
755510 Introduced Species Study 2010 2010-05-31 Redwood Creek - Shipping Non-native 37.5120 -122.2109
755511 Introduced Species Study 2011 2011-04-19 Pump-A-Head Dock Non-native 33.7026 -118.0542
755512 Introduced Species Study 2011 2011-04-19 Back Bay Marina Non-native 33.6194 -117.8933
755513 Introduced Species Study 2011 2011-04-19 Balboa Coves Non-native 33.6213 -117.9364
755514 Introduced Species Study 2011 2011-04-19 Newport Bay Harbor Entrance Non-native 33.5974 -117.8798
755515 Introduced Species Study 2011 2011-04-21 Long Beach Downtown Marina - ISS Non-native 33.7594 -118.1866
755516 Introduced Species Study 2011 2011-05-05 Ocean Institute Dock Non-native 33.4622 -117.7063
758434 Paquette and Cadien 1996 1993 Long Beach Harbor Non-native 33.7552 -118.2157
758435 Ranasinghe et al. 2005 1998 Los Angeles/Long Beach Harbors Non-native 33.7632 -118.2526
758436 Ranasinghe et al. 2005 1998 Anaheim Bay Non-native 33.7333 -118.0894
758437 MEC Analytical Systems, Inc. et al. 2002 (Los Angeles/Long Beach Baseline Study of 2000) 2000 Los Angeles/Long Beach Harbor Complex Non-native 33.7632 -118.2526
819240 Ruiz GM, Chang AL, and JB Geller (2021) 2018 Queensway Bay None 33.7554 -118.1904
819241 Ruiz GM, Chang AL, and JB Geller (2021) 2018 Island Grissom None 33.7625 -118.1782
819242 Ruiz GM, Chang AL, and JB Geller (2021) 2018 Belmont Shore None 33.7426 -118.1212
819243 Ruiz GM, Chang AL, and JB Geller (2021) 2018 Seal Beach None 33.7360 -118.1107
819244 Ruiz GM, Chang AL, and JB Geller (2021) 2018 Cabrillo Way Marina None 33.7160 -118.2820
819245 Ruiz GM, Chang AL, and JB Geller (2021) 2018 San Pedro Marina None 33.7350 -118.2778
819246 Ruiz GM, Chang AL, and JB Geller (2021) 2018 Reservation Point None 33.7223 -118.2649
819247 Ruiz GM, Chang AL, and JB Geller (2021) 2018 Pier300 None 33.7321 -118.2679
819248 Ruiz GM, Chang AL, and JB Geller (2021) 2018 Island Yacht Anchorage None 33.7319 -118.2386
819249 Ruiz GM, Chang AL, and JB Geller (2021) 2018 Consolodated Slip None 33.7728 -118.2494

References

Bousfield, E.L. (1973) <missing title>, Comstock Publishing Associates, Ithaca, NY. Pp. <missing location>

California Department of Fish and Wildlife (2014) Introduced Aquatic Species in California Bays and Harbors, 2011 Survey, California Department of Fish and Wildlife, Sacramento CA. Pp. 1-36

Chapman, John W. (2007) The Light and Smith Manual: Intertidal invertebrates from Central California to Oregon (4th edition), University of California Press, Berkeley CA. Pp. 545-611

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>

Cohen, Andrew; and 16 authors. (1998) <missing title>, Washington State Department of Natural Resources, Olympia, Washington. Pp. 1-37

Foss, Stephen (2009) <missing title>, California Department of Fish and Game, Sacramento CA. Pp. <missing location>

Hirayama, Akira (1986) Two species of Synchelidium (Crustacea: Amphipoda: Oedicerotidae) from the seacoast of northern Japan, Zoological Science 3: 357-366

Hirayama, Akira (1992) Oedicerotidae (Crustacea: Amphipoda) from Hong Kong, Asian Marine Biology 9: 139-166

Imbach, Marilyn Clark (1967) Gammaridean Amphipoda from the South China Sea, Naga Reports: Scientific Results of Marine Investigations of the South China Sea 4(1): 39-167

Jo, Young Won (1990) Oedicerotid Amphipoda (Crustacea) from shallow waters of Korea, Beaufortia 39(5): 155-200

Paquette, Carol; Cadien, Don 1996 <em>Eochelidium</em> sp. A; Southern California Association of Marine Invertebrate Taxonomists. <missing URL>



Ranasinghe, J. Ananda and 6 authors. (2005) The prevalence of non-indigenous species in southern California embayments and their effects on benthic macroinvertebrate communities, Biological Invasions 7: 679-686