Invasion History

First Non-native North American Tidal Record: 1963
First Non-native West Coast Tidal Record: 1963
First Non-native East/Gulf Coast Tidal Record:

General Invasion History:

The clam Laternula gracilis was first described from Port Curtis, Australia, and has a broad native range in the Indo-West Pacific, from Vladivostok to Singapore and Tasmania (Golikov et al. 1976; Carlton 1979; Academy of Natural Sciences of Philadelphia 2006; Tan et al. 2010). In 1963 and 1965, several specimens were found in Coos Bay, Oregon (Keen 1969, cited by Carlton 1979). Carlton considered it 'almost certainly established' but no further specimens were collected in Coos Bay (Carlton 1989). However, in 1995-1996, it was collected in Humboldt Bay, California, where the population appears to be established (Miller et al. 1999; Coan and Valentich-Scott, in Carlton 2007).

North American Invasion History:

Invasion History on the West Coast:

Two specimens of Laternula gracilis were collected in Coos Bay, Oregon in 1963, plus two more, and two valves in 1965 (Keen 1969, cited by Carlton 1979). No other specimens were collected in Coos Bay (Carlton 1989). However, in 1995-1996, 33 specimens were collected in northeast Humboldt Bay, California, where the population appears to be established (Miller et al. 1999; Coan and Valentich-Scott, in Carlton 2007). These specimens were found in mudflats in the high intertidal, sites that may have been missed by other surveys (Miller et al. 1999). Laternula gracilis is also reported to be established in Willapa Bay, Washington (in 1998, Chapman, pers. comm., cited by Boyd 2002; Wonham and Carlton 2005). Ballast water and transplants of oysters from Japan, are possible vectors (Miller et al. 1999).


Laternula gracilis from Asian populations can reach up to 45 mm in size, but the largest specimen from American populations was 20 mm (Miller et al. 1999). Its two valves are roughly elliptical, with an umbo in the center of the dorsal edge. The anterior shoulder is higher than the posterior one, so that the outline of the shell slopes below the umbo. The ligament connecting the valves is mostly internal, and both valves have a chondropore (a spoon like depression in the interior of the shell below the umbo) and lithodesma (a small, shell plate, covering the interior of the ligament). The shell has a pearly and a distinct pallial sinus (Miller et al. 1999; Coan et al. 2000; Coan and Valentich-Scott, in Carlton 2007).


Taxonomic Tree

Kingdom:   Animalia
Phylum:   Mollusca
Class:   Bivalvia
Order:   Pholadomyoida
Family:   Laternulidae
Genus:   Laternula
Species:   gracilis


Anatina marilina  (Reeve, 1860)
Anatina gracilis (Reeve, 1860)
Anatina cristella (Reeve, 1863)
Anatina limicola (Reeve, 1863)
Anatina kamkurama (Pilsbry, 1895)
Anatina peichiliensis (Grabau & King, 1928)
Laternula limicola (None, None)
Laternula marilina (None, None)
(None, None)

Potentially Misidentified Species

Cryptomya californica
native West Coast clam, Alaska-Peru

Mya arenaria
introduced, California to Alaska



The clam Laternula gracilis inhabits soft, silty and sandy sediments in high intertidal to subtidal mudflats. It has been collected at 20 m, but is much more common in shallow waters.

It tolerates salinities from 7 to 33 PSU, but grows best at 24-30 PSU (Kommendantov and Orlova 1991; Zhuang 2005). The optimal range of salinity for larval development was 17-27 PSU (Kommendantov and Orlova 1991; Zhuang 2005). Much of its food appears to consist of benthic diatoms and detritus, based on stable isotope analysis (Kanaya et al. 2008). Shells commonly grew to 45 mm in Taiwan (Hsueh 2003), but the largest specimen found in Coos Bay was 20 mm, while the largest in Humboldt Bay was 11.5 mm (Miller et al. 1999).



Trophic Status:

Suspension Feeder



General HabitatUnstructured BottomNone
General HabitatSalt-brackish marshNone
Salinity RangePolyhaline18-30 PSU
Salinity RangeEuhaline30-40 PSU
Tidal RangeSubtidalNone
Tidal RangeLow IntertidalNone
Vertical HabitatEndobenthicNone

Tolerances and Life History Parameters

Minimum Salinity (‰)7Experimental (Zhuang 2005)
Maximum Salinity (‰)33Experimental, highest tested (Zhuang 2005)
Minimum Reproductive Salinity17Optimal range for larval development (Kommendantov and Orlova 1991; Zhuang 2005).
Maximum Reproductive Salinity27Optimal range for larval development (Kommendantov and Orlova 1991; Zhuang 2005).
Minimum Duration3Larval duration at 25-27 C (Kommendantov and Orlova 1991).
Maximum Duration4Larval duration at 25-27 C (Kommendantov and Orlova 1991).
Minimum Length (mm)20Approximate size at spawning, Korea (Kang et al. 2006)
Maximum Length (mm)55In Asian populations, but the largest specimen in the only known American population was 11.5 mm (Miller et al. 1999).
Broad Temperature RangeNoneCold temperate-Tropical
Broad Salinity RangeNonePolyhaline-Euhaline

General Impacts

The clam Laternula gracilis is cultured for food in northern China (Zhuang 2005), but has had no economic or ecological impacts in North America.

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
NWP-4a None 0 Native Estab
AUS-XIV None 0 Native Estab
AUS-XII None 1863 Native Estab
AUS-XI None 0 Native Estab
AUS-X None 0 Native Estab
AUS-VIII None 0 Native Estab
AUS-VII None 0 Native Estab
AUS-IX None 0 Native Estab
AUS-VI None 0 Native Estab
AUS-V None 0 Native Estab
AUS-IV None 0 Native Estab
AUS-I None 0 Native Estab
NWP-3a None 0 Native Estab
NWP-2 None 0 Native Estab
NWP-4b None 0 Native Estab
EAS-III None 0 Native Estab
EAS-VIII None 0 Native Estab
EAS-II None 0 Native Estab
NEP-IV Puget Sound to Northern California 1995 Def Estab
NWP-3b None 0 Native Estab
P130 Humboldt Bay 1995 Def Estab
P170 Coos Bay 1963 Def Extinct
EAS-VI None 0 Native Estab
P270 Willapa Bay 1998 Def Estab
NWP-5 None 0 Native Estab

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude
26609 Miller et al. 1999 1995 1995-01-01 Humboldt Bay General Location Def 40.7864 -124.1922


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