Invertebrates
Antarctic Scallop
Adamussium colbecki · also called Antarctic scallops
Growing slowly for decades on the cold Antarctic seafloor, an Antarctic scallop trades speed for longevity, reaching an unusually large size for a bivalve while still able to clap its shell shut and swim briefly away from danger when needed.
Overview
The Antarctic scallop, Adamussium colbecki, is a Least Concern invertebrate native to ocean and polar habitat across the seafloor of the Antarctic continental shelf. Its unusually large size, exceptionally long lifespan, and slow, cold-adapted metabolism make it one of the more scientifically notable bivalve species found anywhere in the Southern Ocean.
Built to last in a slow, cold world
Where warmer-water scallops grow quickly and live only a few years, the Antarctic scallop has taken the opposite path entirely, trading rapid growth for a slow, steady life that can stretch across several decades on the frigid Antarctic seafloor.
Status
Least Concern, remaining present across suitable seafloor habitat on the Antarctic continental shelf, though detailed long-term population trends are not fully established.
Antarctic Scallop: common questions
How big does the Antarctic scallop grow?
This species grows to an unusually large size for a bivalve mollusc, among the largest scallop species found anywhere in cold polar waters.
How long can an Antarctic scallop live?
This species can live for many decades, an unusually long lifespan made possible by an extremely slow metabolism suited to the cold, food-limited conditions of the Antarctic seafloor.
Can the Antarctic scallop move on its own?
Yes, this species can swim short distances by rapidly clapping its two shell valves together, expelling water and propelling itself away from approaching predators.
Why does the Antarctic scallop grow so slowly?
This species grows extremely slowly compared with related scallop species found in warmer waters, a trade-off linked to its cold environment that also supports its unusually long lifespan.