Mollusca
Clams & relatives

There are dozens of large species of bivalves on this coast. Most if not all are edible and many are commercially exploited. These potentials, combined with decreasing quality of natural habitats, have led to successful culture-industries for numerous species, including Manila clams, oysters, mussels, and scallops.

NOTE the English word “bivalve” originally meant “having two leaves or parts" (as a folding door) and is derived from a Latin word meaning the same thing. The English word “clam” derives from an older word meaning “to hold fast” or “a device to clasp rigidly or hold tight” (hence, clamp); only later was the term applied to burrowing marine bivalves

   

ANIMATION of the snail's odyssey © Thomas Carefoot 2020
map used by the snail in A SNAIL'S ODYSSEY

To navigate through the ODYSSEY:

  • Select a TOPIC from the menu at the top of the screen
  • OR: play the animation to the left
  • OR: follow the snail's ODYSSEY by CLICKING on any X-marked invertebrate on the map above

Phylum Mollusca (lit. “soft” or “shellfish” L.)

Class Bivalvia (lit. “two folding doors” L.), referring to the two parts of a clam or scallop shell joined by a flexible hinge

SubClass Heterodonta (lit. “different tooth” G.), referring to the different patterns of hinge teeth and ligaments that characterise the different families

Order Veneroida, containing the common large clams1, as well as cockles2; about 25 Families are represesented

Order Myoida, containing burrowing and boring bivalves, piddocks and shipworms, as well as geoducks Panopea3 spp.; some five Families are included

NOTE1 recent taxonomic changes concern the butter clam, now Saxidomus gigantea (from S. giganteus), the native littleneck clam, now Leukoma staminea (from Protothaca staminea), and the Japanese littleneck or Manila clam now Ruditapes philippinarum (from Venerupis philiippinarum. Since recent name changes are sometimes reversed or changed again, all older references to these species will bear the older names, but the new names will be used for any new references.

NOTE3 two species of geoducks (geoducs) inhabit the west coast of North America: Panopea generosa from Alaska to California and P. globosa along the Baja coast of Mexico. The first species was formerly known as P. abrupta, but this designation in now valid only for an extinct, fossilised taxon

The Journal of Shellfish Research in 2015 devoted an entire issue of Vol. 34 (March, Issue 1) to the genus Panopea, focussing on the population dynamics, growth, genetics, and aquaculture of five world species. The issue provides an up-to-date summary of the current state of knowledge of this interesting and commercially important genus. Of the 20 papers presented, about half are of interest to the ODYSSEY.

Vadopalas et al.   2010   Malacologia 52: 169
-   2015   J Shellfish Res Vol. 34 (1): 3-202
Courtesy Anne Candida

NOTE2  all Irish, and most folks of a mature age will know of Molly Malone, a fictional fishmonger who plied her trade in Dublin in the late 17th Century.  This delightful ballad was written in her honour in the late 1800s, and a stature of her exists in Dublin:

      In Dublin's fair city
      Where the girls are so pretty
      I first set my eyes on sweet Molly Malone
      As she wheeled her wheelbarrow
      Through the streets broad and narrow
      Crying "cockles and mussels, alive, alive, oh"

      Alive, alive, oh
      Alive, alive, oh
      Crying "cockles and mussels, alive, alive, oh"

      She was a fishmonger
      And sure, t'was no wonder
      For so were her mother and father before
      And they wheeled their barrow
      Through the streets broad and narrow
      Crying "cockles and mussels, alive, alive, oh"

      Alive, alive, oh
      Alive, alive, oh
      Crying "cockles and mussels, alive, alive, oh"

      She died of a fever
      And sure, so one could save her
      And that was the end of sweet Molly Malone
      Now her ghost wheels her barrow
      Through the streets broad and narrow
      Crying "cockles and mussels, alive, alive, oh"

      Alive, alive, oh
      Alive, alive, oh
      Crying "cockles and mussels, alive, alive, oh"

      Alive, alive, oh
      Alive, alive, oh
      Crying "cockles and mussels, alive, alive, oh" 

   

NOTE3 two species of geoducks (geoducs) inhabit the west coast of North America: Panopea generosa from Alaska to California and P. globosa along the Baja coast of Mexico. The first species was formerly known as P. abrupta, but this designation in now valid only for an extinct, fossilised taxon

The Journal of Shellfish Research in 2015 devoted an entire issue of Vol. 34 (March, Issue 1) to the genus Panopea, focussing on the population dynamics, growth, genetics, and aquaculture of five world species. The issue provides an up-to-date summary of the current state of knowledge of this interesting and commercially important genus. Of the 20 papers presented, about half are of interest to the ODYSSEY.