A rare ghostly-white shark has been discovered in the deep waters off Albania… and it isn’t what you think! While great white sharks (Carcharodon carcharias) are no strangers to the Mediterranean, this critically endangered species is native to the dark depths of the region and seldom seen. Recently brought to the surface by a commercial trawler off Sazan Island – an uninhabited military zone off Albania’s coast – at a depth of around 656 feet (200 meters), it is the first known case of leucism in an angular roughshark, Oxynotus centrina.
The catch was remarkable not only because of the species’ rarity but also due to its striking coloration, which scientists later confirmed as a pigment disorder. Unlike albinism, where there is a complete lack of melanin and the iris is red due to underlying blood vessels, leucistic animals retain normal eye pigmentation. In the case of this angular roughshark, while its body was almost entirely pale, the eyes showed no signs of depigmentation, confirming its leucism rather than albinism. Lead author of the study, Andrej Gajić, who heads Sharklab ADRIA in Albania, points out that leucism does not completely prevent melanin production but rather limits it in specific areas or even across the entire body, creating the shark’s ghostly appearance.
Typically, angular roughsharks are a dark gray-brown or black color, helping them blend into their dark deep-sea habitat. This individual? Had pale, whitish-gray patches on its body. Still, despite its unusual coloring, the shark appeared to be in good health, which the scientific community says raises fascinating questions about the role of pigmentation in the lives of deep-sea creatures. Could this lack of pigmentation make the animal more visible to both predators and prey, affecting survival rates? It’s unknown! However, as Gajić points out, the fact that this shark appeared healthy suggests that pigment disorders may not necessarily hinder their ability to feed, escape predators, or reproduce.
But as human activity increasingly impacts the ocean, scientists are exploring whether pollutants and other threats could elevate the likelihood of pigment disorders or other health issues in marine life. Gajić and his colleagues suggest that environmental factors, such as pollution, temperature shifts, and inbreeding in isolated populations, may also play a role in causing pigment changes, although much more research is needed to clarify these influences.
The leucistic angular roughshark is not only a scientific curiosity but a reminder that we still know very little about our deep-sea environment and the animals who call the region home. Each encounter with species like this one offers a glimpse into the complex genetic and environmental factors shaping deep-sea ecosystems; understanding why and how these rare conditions arise could ultimately inform conservation strategies for these vulnerable animals. Meaning these encounters – while very cool – also remind us that protecting these regions and reducing the stressors on marine habitats are essential for ensuring the survival of species that are already facing significant threats.
