For most people, the news of a newly-discovered species often relates to something rare or unusual—perhaps a creature found hiding deep in a tropical forest or another dinosaur from the Canadian Badlands. Yet, these represent only a small portion of the estimated 15,000+ new species described every year by scientists around the world.
But once in a while, I think we should make a bit of noise when something out of the ordinary (that is not a dinosaur, a missing link, a primate or some cute deep-sea octopus) gets discovered in a habitat unfamiliar for most people. And through this, I hope that you’ll gain a better appreciation for the effort involved and the importance of continuing to explore and describe our natural world.
So, with this in mind, let me share the story of a new species I was involved in identifying and describing—a new species of deep-water clam found off Canada’s Atlantic coast.
To best describe our journey in achieving this scientific milestone, I need to step back in time to December 10, 1984, as I was starting my Ph.D. at Memorial University in St. John’s, NL. On that day, I discovered a strange single bivalve shell (about 12 cm long) in a bottom grab sample from a deep fjord along the south coast of Newfoundland. It resembled a scallop. At the time, I was working on marine worms and did not pay much attention to it. About six months later, I had the opportunity to dive at the same location onboard the PISCES IV research submersible.
There, we discovered many scallop-looking bivalves attached to exposed rocky surfaces from about 400 m all the way to the bottom of the fjord, at about 800 m. We were fortunate to be able to collect one live specimen using the hydraulic arm of the submersible.
Doing some basic morphological comparisons with already described species, we came to the conclusion (Gagnon & Haedrich, 2003) that it was the same species found in Europe, the European giant file clam, Acesta excavata. This conclusion was based on only two specimens from the Newfoundland fjord and a few representatives of the European species. (And by the way, these clams are distant cousins of scallops and have nothing to do with the actual giant clams found in tropical waters of the Great Barrier Reef.) But what was most exciting about this discovery is the fact that giant file clams had never been observed in the northwest Atlantic (at least not north of the Caribbean and the Gulf of Mexico).
Now, let’s forward to 2007 when Dr. Ellen Kenchington, a colleague from Fisheries and Oceans Canada in Dartmouth, Nova Scotia, contacted me to tell me that she and her colleagues were finding a lot of similar “scallops”, using the remotely-operated vehicle ROPOS in The Gully, located along the continental slope of the Scotian Shelf. A quick look confirmed that we were dealing with the same group of bivalve; the question was, “Is it the same species”?
To answer this question, we had to wait seven years, using DNA analysis to go along with comparative studies of the clams themselves. My next blog will detail some of the steps required to get to an identification of this new species of giant file clam.