"Finding Nemo," though a charming piece of animation, is a mess of lies. Clownfish live far more interesting lives than chasing down lost larvae, what with their hermaphroditism, sex changes and anemone-sting-neutralizing coats of slime.
But some young clownfish are, for a brief period, nomads. These real-life clownfish would make that other sea-faring Nemo proud, a new study in the journal PLOS ONE shows, as these fish can travel up to 250 miles before settling in new homes.
Researchers from James Cook University in Australia and University of Exeter in the U.K. traveled to two coral reefs off the coast of Oman - the only two spots where the Omani clownfish species live, separated by 250 miles of seawater. By collecting tissue samples from 400 fishes at both spots, the biologists compare fish DNA, creating genetic fingerprints for the two populations.
"Like the accents that we have that allow us to tell an Englishman from an American, fish populations can develop their own genetic signatures," says Hugo Harrison, a marine biologist at James Cook University and an author of the study, in a statement. "We can look at the signature of each fish and tell whether it belongs there or not. It's like finding an Englishman in New York, they stand out."
Most of the migrant fish appeared to travel south, following the winter monsoon currents. This is the farthest distance tracked for any coral-reef-dwelling fish species, according to Stephen Simpson, a University of Exeter biologist and co-author of the report.
For other fish who don't stick close to reefs, however, relocating 250 miles is peanuts. A great white shark named Lydia made history earlier this year, crossing 19,000 miles from Florida through the Atlantic to the coast of the U.K.