New Giant File Clam Species Described by Canadian Scientists

Posted on August 31, 2015

Giant File Clams off coast of Nova Scotia

Canadian researchers have described a new species of giant file clam. The clams were discovered in deep waters off Newfoundland about 30 years ago.

The photograph above shows the new giant file clam species attached to a rocky surface in the Gully Marine Protected Area off the coast of Nova Scotia. The photograph below shows an image of the giant file clam compared to a regular file clam. The giant clam is 9 to 15 centimeters long (3.5 to 6 inches) and two to three times larger than a regular file clam.

Acesta crytodelphe giant file clam compared to regular sized file clam


The species has been named Acesta cryptadelphe. The name means cryptic sibling and refers to the species similarity to a European giant file clam, Acesta excavata.

Dr. Jean-Marc Gagnon, Curator of Invertebrates with the Canadian Museum of Nature in Ottawa, says in a statement, "This is the culmination of a story that began decades ago when, as a Ph.D. student, I first observed this clam in an underwater submersible off the coast of Newfoundland. Originally, we assumed it to be a European species."

Specimens of the giant file clam were obtained by scientists from the Bedford Institute of Oceanography (BIO) in Dartmouth, Nova Scotia using an underwater vehicle called ROPOS. The scientists were able to process DNA from the clams using new genetic technology aboard the oceanographic ship CCGS Hudson.

Dr. Ellen Kenchington, a scientist with BIO, says, "Using all this technology allowed us to photograph and collect intact specimens, and then to process the DNA while at sea. This gave us an early indication that we might have something special. The Gully MPA continues to amaze us with new discoveries. It is an extraordinary place."

A research paper on the newly identified clam was published here in the journal Zootaxa.

Top Photo: Fisheries and Oceans Canada
Second Photo: Laura Sutin © Canadian Museum of Nature