Manta shark species can walk for up to two hours, allowing them to survive in increasingly hostile environments, the researchers say.
Researchers at a university in Florida say a small but courageous species of manta shark with an extraordinary ability to walk on land is evolving to better survive warm seas and climate crisis.
Commonly found on the shallow reefs of Australia and New Guinea, the dragon shark can walk up to 30 meters on dry land using paddle-shaped fins and survive hypoxia, an oxygen deficiency, for up to two hours.
Biologists at Florida Atlantic University (FAU) and their research partners in Australia say these remarkable abilities allow reef-dwelling sharks to survive in increasingly hostile environments as conditions change.
“Such locomotor characteristics may not only be the key to survival, but may also be related to their sustained physiological performance under challenging environmental conditions, including those associated with climate change,” says the study, published in the scientific journal Journal of Integrative and Comparative Biology .
“Findings to date suggest that this species has adaptations to tolerate some, but perhaps not all, of the challenging conditions anticipated for the 21st century.”
Sharks with exceptional abilities
Marianne Porter, professor of biomechanics in the FAU’s department of biological sciences, said sharks can walk slowly and quickly, as well as swim, giving them an exceptional ability to traverse land and reach more favorable environments than other species.
“You might not think of beautiful tropical beaches as harsh, but in fact the environments of rock pools and coral reefs are quite harsh, subject to hot temperatures when the tide is low and a lot of change, a lot happens when the tide is low. up and out,” he said.
“These small sharks can move from one pool to another, which allows them to access new pools to look for food or pools with better oxygenated water.
“Our collaborators in Australia have found that they can withstand changing climate conditions very well. These sharks are excellent models to start looking at how these changes in conditions might affect vertebrates in general and other species, and can help us reflect on what we might see in the oceans of the future.”
Epaulettes aren’t the only shark species known to have ambulatory abilities. In 2013, researchers in Indonesia discovered a species that uses its fins to “walk” across the ocean floor in search of small fish and crustaceans.
Nonetheless, a study A 2020 study by researchers at the University of Queensland and international partners found that at least nine species of sharks used fins to walk in shallow water.
What sets epaulettes apart, however, is their long-term tolerance to hypoxia and their ability to not only survive on land, but also be able to walk distances of up to 30 times their body length.
“Your ability to move and walk from place to place is very, very important,” Porter said.
The researchers noted that this gave the sharks greater agility to evade predators and reach areas with more plentiful food and less competition for it.
By Richard Luscombe. Article in English