| Range |
Relatively scarce in Oregon (Tillamook, Yaquina, and Coos Bay most productive) (Chew and Ma 1987)
Baja, California to Alaska (Wolotira et al. 1989 in Emmett et al. 1991) |
| Habitat |
Usually in upper 2 cm of sediment (Paul and Feder 1973 in Chew and Ma 1987)
Estuaries (Emmett et al. 1991) |
| Substrate |
Higher adult density on sand versus mud (60% more)
Optimal–coarse sand/fine gravel (Chew and Ma 1987)
Gravel and mud beaches (Wolotira et al. 1989 in Emmett et al. 1991)
Firm gravel or clay-gravel (Quayle and Bourne 1972; Goodwin and Shaul 1978 both in Emmett et al. 1991) |
| Depth range (meters) |
Intertidal to 37
Usually -1–1.3 m mean lower low water (Chew and Ma 1987 in Emmett et al. 1991) |
| General Temperature Range (°C) |
0–25
10–15 (optimum off Newport) (Chew and Ma 1987)
Above 25 is lethal (Strathman et al. 1987 in Emmett et al. 1991) |
| General Salinity Range (ppt) |
27–32 (optimum off Newport, Oregon) (Chew and Ma 1987)
Mesohaline to euryhaline (Glude 1978; Bernard 1983a both in Emmett et al. 1991) |
| Average Maximum Overall Length (cm) |
5.4–6.3 diameter
8 (Quayle and Bourne1972 in Emmett et al. 1991) |
| Length When Harvested (cm) |
5.1 (average)
This is the smallest commercial bivalve (Chew and Ma 1987) |
| Overall Maximum Age (years) |
10 British Columbia (Chew and Ma 1987)
13–16 (Fraser and Smith 1928; Abbott 1974; Chew and Ma 1987 all in Emmett et al. 1991) |
| Mortality Rate |
Highest at end of first year after settlement (Chew and Ma 1987) |
| Overall Age at Maturity (years) |
2 (50% spawn)
3 (most spawn) (Chew and Ma 1987)
1.5 (Emmett et al. 1991) |
| Overall Length at Maturity (cm) |
2.5 (50% mature)
3.5 (most mature) (Chew and Ma 1987)
1.5–3.5 (Emmett et al. 1991) |
| Type of Reproduction |
Gonochoristic, oviparous, iteroparous (Emmett et al. 1991) |
| Fecundity |
Unknown (Emmett et al. 1991) |
| Spawning Behavior |
Broadcast spawner (Emmett et al. 1991) |
| Time of Year of Spawning |
February and March (Chew and Ma 1987)
March–August in Oregon (Robinson and Breese 1982 in Emmett et al. 1991) |
| Spawning/Temperature Relationship (°C) |
Timing depends on temperature (Chew and Ma 1987) |
| Habitat where Eggs are found |
Pelagic (Paul and Feder in Emmett et al. 1991) |
| Days to Hatch |
Trochophore larval stage begins 12 hours post-fertilization
Veliger within next 24 hours (Chew and Ma 1987) |
| Habitat where Larvae are found |
Pelagic (Paul and Feder in Emmett et al. 1991) |
| Days in Larval Stage |
21 (temperature dependent) (Chew and Ma 1987) |
| Larval Food Preference |
Phytoplankton (0.15 mm–after one week) (Chew and Ma 1987)
Phytoplankton, Benthic Diatoms, Detritus (Emmett et al. 1991) |
| Habitat where Juveniles are found |
Small clams are epifaunal (Paul and Feder in Emmett et al. 1991)
Larger ones are found from 5–20 cm within sediment (Emmett et al. 1991) |
| Juvenile Food Preference |
Post larvae eat plankton smaller than 10 micrometers in diameter (Chew and Ma 1987)
Phytoplankton, Benthic Diatoms, Detritus (Emmett et al. 1991) |
| Habitat where Adults are found (depth in meters) |
5–20 cm within sediment (Emmett et al. 1991) |
| Temperature for Adult Survival (°C) |
12–18 (optimal) (Bernard 1983b in Emmett et al. 1991) |
| Salinity for Adult Survival (ppt) |
24–31 (optimal) (Bernard 1983b in Emmett et al. 1991) |
| Adult Feeding Type |
Suspension, filter feeder (Emmett et al. 1991) |
| Adult Food Preference |
Phytoplankton, Benthic Diatoms, Detritus (Emmett et al. 1991) |
| Amount of Food Eaten in Laboratory Setting |
15–150 mg/l suspended food in water (optimal) (Bernard 1983b in Emmett et al. 1991)
Survives in aquariums with open systems or with algal culture in a closed system (Anderson 2001) |
| Additional Laboratory Findings |
15–20°C–optimal temperature to rear in laboratory setting (Strathmann et al. 1987 in Emmett et al. 1991) |
| Commercial Fishery |
Important (Chew and Ma 1987) |
| Market |
Expected to remain favorable (Chew and Ma 1987)
|
| Sold Fresh or Frozen |
Fresh in the shell
Frozen (Wolotira et al. 1989 in Emmett et al. 1991) |
| Style Species is Sold |
Canned (Paul and Feder 1976 in Emmett et al. 1991) |
| Parasites or Disease |
No epidemic diseases have been found (Quayle and Bourne 1972 in Chew and Ma 1987)
Larval tapeworm Echeneibothrium but not harmful to humans (Shaw 1985 Chew and Ma 1987) |
| Additional Remarks |
Can live several days out of water
Manila Clams have been farmed and leads production versus this species and butter clams (Chew and Ma 1987)
Plastic netting used to stabilize substrate and reduce predation (Anderson and Chew 1980 in Chew and Ma 1987) |
