These giant freshwater crabs might just be your new Roman Empire.
Archaeologists studying Trajan’s Forum, a historic Roman site, in 2005 discovered an ancient species of crab, Potamon fluviatile. The only species of freshwater crab native to Italy, researchers suspect it has roamed the region since ancient times – long before it was known for gelato and pasta.
“The Roman underground, especially in the area of the ancient Roman forum, is very rich in water, with many passages and shelters for survival,” Marco Seminara, an environmental biologist at Rome’s Sapienza University, told National Geographic.
“I’m not surprised that these animals have lived there for so long.
The collapse of the Roman Empire gave the crabs a low profile so they could safely maneuver the city’s underground sewage systems, surfacing only at night to feed on animal remains and other organic matter.
Nature photographer Emanule Biggi described the crabs as the “Wall-E of nature”. He wrote:
“Its wild temperament protects it from disturbance by many predators, such as water snakes and smaller birds, and even from non-native species such as the Louisiana freshwater crayfish.”
These days, however, data suggests that the species may be under threat.
While the researchers caught and identified about 500 crabs during the peak of their studies from 2004 to 2006, rising temperatures made them almost impossible to find.
Despite their large size—scientists say Roman crabs were 13 to 20% larger than other members of their species—they were able to tunnel deeper in their hidden canals to stay cool as the surface of their home became warmer and less. wet.
Their dwindling population is also due to human excavations, which have uncovered a network of underground canals that once protected the crabs. Now predators such as seagulls and crows have invaded crab habitats.
Seminara told National Geographic that these days he finds more crab body parts than live crabs. The species is also listed as “near threatened” on the IUCN Red List of Threatened Species.
To save the species – which has been around for centuries – experts say they need funding to study them.
In 2020, the Colosseum recruited naturalists to help study and monitor the various species living in the area between the Colosseum and the Roman Forum. Seminara joined naturalist Gianluca Damiani on this mission, but the results were much less exciting than the original discovery of the species.
Only six new crabs have been identified in the past three years, Damiani told National Geographic.
“Now they’ve gone even deeper,” Damiani said. “Can’t find them.”
Although scientists have not concluded that the crabs are currently facing extinction, they can say that their numbers are rapidly declining.
“We would like to study these animals because they deserve not only to be studied but also to be saved,” Damiani said. “This population cannot disappear.
Damiani and his colleagues applied for permission to put up nets and signs informing people about the crabs, although the city denied those requests.
While he blames Rome for wanting to leave the area unchanged for tourists, Seminara argues that the interest in these crabs would be a sight to see in itself.
“Their existence is certainly folklore. It would be like finding a crab living in Central Park,” he explained to National Geographic. “This is a unique animal.
“The fact that the Foru Romanu is the only large freshwater crustacean we have in Italian waters is and will always be a matter of awe.”
Currently, crab species that also live in other Mediterranean areas such as Malta and the Balkan Peninsula are protected by local and national laws. However, experts believe that environmental education and communication are the keys to saving the crabs.
For Damiani, it starts with sharing their story.
“A few steps from the Colosseum in the heart of Rome, extraordinary crustaceans survive,” he writes in the Instagram caption, showing his pictures of crabs in their natural habitat.
“The last survivors hide among the sewers and canals,” he continues, “descending deeper and deeper, in an urban jungle that is rapidly changing.”
Header image courtesy of Amphipolis (CC BY-SA 2.0)