Bivalves

The following species have been observed thus far in surveys of Fishing Bay and Indian Island. 
 Look for future updates.
cockles

  Nuttall's Cockle

(Clinocardium nuttallii)


     Look for: To 5-1/2"
                         Shell is as high as it is long
                         34–38 ribs with wavy lines across margins
                         Wavy margin of shell "locks" one half to
                                 the other.
                         Thick, hard shell discourages predators.
                         Short siphon
     Habitat:  Sand-gravel in sheltered waters
                         Intertidal to 100'
                         Lives just under the surface of the
                                sediment.
     Notes:     Species may live to 16 years.
                        Has spectacular leaping escape response.
                        Eaten by sunflower star and spiny pink
                                 star.
                        Flesh around outer margin of shell has tiny
                                 tentacles 
and eyes 
used to detect
                                 predators.
                        Can live up to 19 years.
                        Sometimes called "heart cockle" for its
                                  heart-like
 shape.





horse clams

Horse Clam

(also known as Fat Gaper Clam)

(Tresus capax)



     Look for: Smooth, oval shell up to 7" long
                         Can weigh from 1 to 4 pounds
                         Length of shell typically 1-1/2 times height
                         Shell is hinged with a small spoon-shaped
                                 socket.
                        Shell has fine concentric ribbing.
                        When exposed at low tide, neck can be
                                 visible above
 the sediment.
                         The siphon has hard valves on each side 
                                of 
the
 siphon opening.
                        Shoots jet of water when disturbed as
                              part of an escape response.
                        When two matching shells are pressed
                                 together, there 
is an oval gap at 
                                 one end.
     Habitat:  Sand and mud, intertidal to 100'
                         Burrows only about 25" down into
                                 sediment.
     Notes: Largest shells were used by native people as
                                 bowls 
and ladles.   
                        Traditionally harvested and eaten by
                                  native peoples. 
                        Eaten by crabs and giant pink sea star.
                      

macoma clams


  Bent-nose Macoma

(Macoma nasuta)


     Look for:  Small, to 3"
                          Thin white shell
                           Shell bends sharply and comes to a point
                                 near
 the posterior end.
                          Orange siphons collect detritus off sea
                                   bottom.
                           Uses its foot to dig sideways, not down.
     Habitat:  Intertidal sand to 165'
                         Buried 4–6"
      Notes: Native species
                     Can tolerate low oxygen levels
  



tellin clams

Varnish Clam

(also known as Dark Mahogany Clam)

(Nuttallia obscurata)


     Look for:  To 2-1/4" long
                          Thin, oval, flat shell
                          Outer shell is covered in a thin brown
                                 coating that 
may peel.
                          Shell interior is bright purple or blue.
     Habitat:   Buried to 8" in sand/gravel
                          High to mid intertidal
                          Often in areas of freshwater seepage
     Note: Invasive species, introduced from Japan in
                         the 1980s. 




venus clams


Pacific Littleneck
(also known as Steamer Clam)
(Leukoma staminea)

     Look for:  To 3" wide
                           White to brown, often with angular
                                 patterns
                           Color and markings may vary.
                           Round to oval shell
                           Both concentric and radial ribbing
                           Short, fused siphons
                           Internal teeth on hinges that can be seen
                                 and felt
     Habitat: Buried to 4" or more in gravel, sand or
                                  mud
                         Mid intertidal to 35'
     Notes: Less abundant than Manila or butter clams
                    Harvested as steamer and for chowder
                    Life span 8–14 years
                    Fast-growing
                    Often confused with Manila clam
                    Eaten by sea stars, crabs, fish, gulls and
                                 crows      


  

 Japanese Littleneck
(also known as  Manila Clam or Steamer Clam)
(Venerupis philippinarum)

     Look for:  Elongated oval shell, to 3" long
                          Both concentric and radial ribbing
                          Stronger radial ribs, esp. at posterior end
                          Outside of shell varies from grey to brown.
                          Inside of the shell is often purple or 
                                yellow.
                          Inside edge is smooth to the touch.
                          Often has streaked patterns, and
                                sometimes has  angular
  patterns like
                                 the Pacific littleneck.
                          Markings may vary.
                          Internal teeth on hinges that can be seen
                                     and felt
     Habitat:  Buried to 4" in gravel, sand or mud
                         High intertidal
     Notes:    Species was introduced accidentally from
                                 Japan.
                        Local populations were first recorded in
                                  British Columbia  in 1936.
                        Life span 8–11 years
                        Often confused with Pacific littleneck



 Butter Clam
(also called Smooth Washington Clam)
(Saxidomus gigantea)

     Look for:  Large oval to square shells, to 5-1/4" long
                          Concentric ribbing
                          Typically white to grey
                          Inside of shell is smooth but not glossy
                          Deep muscle scars
                        Internal teeth on hinges can be seen or felt
     Habitat: Buried to 12" deep in gravel, sand or mud
                        Mid intertidal to 130'
      Notes:   Lifespan to 20 years or more
                       Commonly harvested and eaten
                       Shell is sometimes confused with that of the
                                 horse clam, but has no hinge socket.


mussels


Pacific Blue Mussel

(Mytilus edulis)

     Look for: Elongated, triangular shell
                         Blue to black, sometimes tan to brown
                          Lives in colonies
     Habitat:  On rocks in sheltered locations
                          Intertidal to 16'
     Notes:  Attached to rocks with strong byssal threads
                     Only local mussel




false-jingles

Green False-Jingle

(Pododesmus macrochisma)

(also called rock oyster, jingle shells, blister shells)

    Look for:  Roughly circular shell
                        Up to 5-1/4" in diameter, but often smaller
                        Lower shell is thin and flat with a pear-
                            shaped hole towards one end for its short,
                            thick byssus.
                            Bottom shell often iridescent green
                        Top shell is humped with a grey to white
                             exterior and has a small valve sealing off
                             the peak.
                        Polished interior.
                        Shell will grow to fit the contours of the
                             substrate.
     Habitat:   Attached to rocks
                           Intertidal to 295'
      Notes: There may be another sub-species, P.
                             macrochisma cepio
Nutall's cockle

Nutall's cockle









horse clam
    
 spoon-shaped socket hinge                 horse clam siphon





bent-nose macoma




varnish clam











Pacific littleneck










Japanese littleneck/Manila clam










butter clam



Pacific blue mussel





green false-jingle, inside and outside of top shell