One Tiny Mollusk, One Big Discovery

No matter the size of the organism, the Academy is always proud to share our scientific discoveries. We reached out Tobias Tagliaferro, a recent Drexel co-op in the Academy’s Malacology Department and co-author on an upcoming paper, to learn more about a very small bivalve, freshly discovered, that has a truly monumental impact on our understanding of the natural world.

Tell us more about yourself. 

I am a senior in environmental science in Drexel University’s Department of Biodiversity, Earth and Environmental Science, expected to graduate in the summer of 2024. My experience with environmental research ranges from volunteering at the Academy’s Outside In handling giant bugs and snakes to taking winter excursions to scrape spotted lanternfly eggs off of trees. I enjoy marine science and hope to continue pursuing it in my career. 

I am also a transgender man! It only occurred to me recently that I am now among the first “out” transgender scientists who have discovered a species. There aren’t many trans people in STEM, so this is really something to celebrate. 

What is the species you’ve discovered? 

This bivalve is a tiny clam that grows to 2–3 millimeters long as an adult, which is about the size of a grain of rice. Bivalves include clams, mussels, oysters and scallops. The name “bivalve” comes from the prefix “bi-” meaning “two” and “valvae” or leaves of a door for the left and right parts of their shell. Most bivalves eat things like algae. 

This clam is a septibranch, which means that it is a carnivore. It lives at least 200 meters under the ocean surface where sunlight is scarce, making herbivory nearly impossible. It burrows in the sand and consumes microscopic crustaceans. Its specialized mouth-valve has tentacles around it to help grab onto prey in the same way an anemone does.  

Bivalves, as a whole, are 500 million years old, even older than dinosaurs. Very little is known about these guys, so, at this point, any research about them is a breakthrough.

Only one other species in this group, called Trigonulina ornata, lives in the Atlantic Ocean. Since this species looks much different from T. ornata, it was easy to tell that we found something new. The main feature that distinguishes the two are the large channels, or “canals.”

The clam is also much smaller than T. ornata which is typically around 4–6 millimeters long. This clam was found near Charleston, South Carolina in the same habitat as T. ornata, but it is currently unclear how large their habitat is, since T. ornata is known to live in warm coastal waters in the western Atlantic and Gulf of Mexico.

What does this work involve and why is it important? 

My work in the Malacology department focused mainly on the Campbell collection where Lyle Campbell, an evolutionary geologist, spent 20 years collecting shells from the South Carolina coast. He kindly labeled them with their locations, collection dates and taxonomic identification as far down as he could go. They came to the Academy in zip-close bags and cereal boxes.  

I spent my six-month co-op organizing his collection alphabetically by genus in one big cabinet. There were about 30,000 individual shells and over 10,000 lots. This project is a time capsule of South Carolina from the 1970s–1990s and can easily measure biodiversity now versus then. Ocean acidification is decimating mollusk populations and having a measure of both their populations and their shell composition at different times gives malacologists a tool to see how much has changed now. 

This tiny clam had been sitting in storage since the 1990s before it was identified as new. It is surprisingly common in the curatorial world for there to be a decades-long gap between when a species is found in the field and when it is named. Campbell suspected the clam was special and left a note about it with the original specimens, then it was confirmed after I took pictures of them under the electron microscope.  

Collections Manager of Malacology Paul Callomon used his contacts from across the world to find images and shells of the living Trigonulina species to compare to this one. He even obtained images of the holotype, or the first known specimen, of T. ornata. Once we were sure this one looked nothing like the living species, we started working on our manuscript. 

My time at the Academy has also significantly aided in my environmental science education. Working in Malacology provided the opportunity for me and other co-op students to put into practice skills that we learned in classes, such as GIS and taxonomic identification. Dr. Rosenberg and Dr. Callomon give co-ops a unique and supportive environment to enter the fields of biology, curation and environmental science. I feel this is exactly what the co-op system was designed for.  

I started my co-op confused about my education and career path, but I left having switched majors with skills and experience under my belt to build myself a future.