3 December, 2024 News stories

A new species of tusk shell, a burrowing marine mollusc, has been discovered in deep, North Atlantic waters by scientists from British Antarctic Survey and the Senckenberg Society for Nature Research. The newly discovered mollusc lives in the abyss – below 3,300m – with an anemone on its shell, an arrangement that has not been seen before in this region.  

The team collected several specimens of the new tusk shell mollusc with anemones from the seafloor and observed many more using seafloor imaging. The anemone changes the burrowing lifestyle of the mollusc which is unable to burrow as deep as it could without its passenger.  

Lead-author, Katrin Linse, Senior Biodiversity Biologist at BAS, says:

“It was exciting to discover a new species, but realising its living arrangement has not been seen before in the region in such deep waters was truly fascinating! It serves as a reminder that we know so little about life in the deep, particularly the way that it adapts and how species pull together to benefit from each other’s presence.”

A close up of a long, cone-shaped species which is coloured white at its tip, tapering down to a beige, then fleshy pink colour at its middle, and returning to a translucent beige at the widest part of its cone. It is pictured in the deep sea, and so the background is pitch black
New species, Fissidentalium aurae, discovered in Atlantic waters

Life in the abyss is hard. No sunlight reaches this depth and very few humans have been this deep in special submersibles. To investigate life on the abyssal ocean floor, Katrin Linse and colleagues on board the RV Sonne used a small net, known as an Agassiz trawl which can be deployed thousands of metres deep, to collect samples from the floor of the Labrador Sea between north-eastern Canada and western Greenland.  

They collected several specimens of the new mollusc, which at 1.1 cm in diameter and 5.5 cm long is larger than its closest tusk shell relatives. It is slightly curved, with 60 ribs, and a member of the genus Fissidentalium which has over 60 known species. They named it Fissidentalium aurae, after the Latin word for breeze, referring to the windy conditions during the expedition.  

Co-author Jenny Neuhaus, PhD student at Senckenberg, sampled DNA from the anemone and checked its genetic barcode against known barcodes in genetic databases, resulting with no close match. The position of the anemone in the tree of life and its scientific name is a riddle still to be solved.

A young woman, her hair tied up in a bun, is seen from above sitting at a desk, which holds a variety of scientific equipment (e.g. beakers, test tubes, sample racks). She is wearing blue gloves, and with one hand holds a sample of anemone DNA. Facing away from the camera, she is referring to a piece of paper in her other hand, which allows her to tell if the sample she is holding matches pre-existing genetic data, confirming whether the team have found a new species of mollusc
PhD student, Jenny Neuhaus, sampling anemone DNA to match against existing genetic databases

The association between a burrowing tusk shell with an anemone has been previously seen in the deep Pacific Ocean, but never in the Atlantic. The research underlines the benefit of deep-sea imagery to support descriptions of species with information on their habitat and ecology.  

“The discovery of this beautiful species shows that the deep sea never ceases to surprise us.” says Jenny Neuhaus. “Not only is it fascinating to scientists to find new species, but also sparks curiosity in the general public. Last week, our research earned a science award sponsored by the maritime city of Wilhelmshaven. We are grateful for this recognition, which emphasises the importance of collaborative efforts in deep-sea research.”  

The full research has been published in the journal Marine Biodiversity

Learn more about lead author, Katrin Linse