MIAMI _ It turns out pythons invading South Florida do more than just gobble up native species and take over their turf.
A new study has found the snakes are also spreading a new lung parasite to native snakes in South Florida and contracting similar local bugs, creating a "spillover and spillback" cycle of infection. Biologists worry that could amplify the spread of the parasite beyond what would normally occur.
"We frequently look at obvious impacts from these species, like what they eat," said University of Florida biologist and co-author Frank Mazzotti. "But the impacts may not always be as obvious and this is a classic example."
Mazzotti said the discovery is the first time researchers have ever looked at diseases or parasites in Florida pythons that might potentially spread to native animals. Finding them on a first foray is a bad sign, he said.
"We're always depressed when the first time you look for something you find it," he said. "There could be others as well."
For the study, researchers from UF, Auburn University and Everglades National Park collected 498 native snakes from 26 species and 805 pythons between 2004 and 2016. Pythons were either killed as part of removal efforts or road kills. All the native snakes, collected throughout South Florida and in Georgia, Alabama and North Florida, were road kills.
During necropsies, biologists searched for the tongue-shaped parasites, called pentastomes, which were preserved and then later genetically sequenced.
The good news so far is the python parasite was not found in snakes beyond South Florida. How it spreads is less clear. In Australia, pythons eat frogs that act as hosts, but South Florida pythons are not known to eat frogs. In Kenya, the parasite turned up in a shrew, suggesting rodents may also act as hosts in Florida.
Researchers plan on looking for other diseases that might potentially spread, Mazzotti said, and will also examine invasive tegus, which carry similar lung parasites.
While it's unclear what impact the parasite is having on native snakes, it's probably not good, he said.
"Will it be proved lethal to native snakes? Who knows," Mazzotti said. "But we don't want to find out."
