Greenland sharks (Somniosus microcephalus) live a very long life… but that doesn’t mean it’s a comfortable one.

One of the largest cartilaginous fishes, scientists have estimated Greenland sharks live to at least 250 years and may live over 500, making it the world’s longest living vertebrate. Reaching lengths of 24 feet (7.3 m), they are known to inhabit the cold waters of the North Atlantic and Arctic Oceans, although one specimen was recently observed in the warm waters of the Caribbean.

As with most bony fishes, elasmobranchs (sharks and their relatives) are known to host numerous ecto- and endoparasite species. Greenland sharks are known to famously be parasitized by the copepod scientifically known as Ommatokoita elongata. The pinkish-white copepod latches onto the shark’s eye, destroying the corneal tissue, resulting in eventual partial blindness. Various nature documentaries have zoomed in on this worm-like parasite. However, University of Windsor scientist Eric Ste-Marie recently retrieved a parasite that has not been previously seen in these cold-water predators.

A barnacle.

Specifically, the parasitic barnacle (Anelasma squalicola). While it has similarities in general body shape to the pedunculate, or stalked, barnacles, there is one key difference that senior Cal Academy researcher Bob van Syoc explained: “The stalk has evolved various modifications that serve to function as a feeding appendage rather than simply a site of attachment; [it embeds itself]