In the Pixar hit movie Finding Nemo, the father clownfish made an epic journey across the ocean meeting all sort of marine creatures to find and be reunited with his young son and while the story is fictional, it appears that the creators of the movie got something right --clownfish can travel long distances.
Findings of a new study suggest that clownfish can indeed swim hundreds of kilometers despite of their size albeit unlike in the movie where the adult fish did the swimming, it is the one-week old baby clownfish that can travel hundreds of kilometers to find a new reef.
For the study published in the journal PLOS ONE on Sept. 17, Stephen Simpson, from the University of Exeter in the UK, and colleagues captured hundreds of Omani clownfish (Amphiprion omanensis) that live in two coral reefs over 400 kilometers apart.
The researchers took harmless genetic samples of the fishes before releasing them back into the ocean and these revealed that the genetic signature of the fishes living in the northern reef is different from that of the fishes living on the southern reef just like people from different geographic locations having distinct accents.
The researchers also found that of the 260 clownfish from the southern reef, 14 or 5.4 percent of their number came from the north. One fish that live in the northern reef, on the other hand, migrated from the south providing evidence that despite the distance between two reefs, the two groups were swapping young clownfish.
"Local migrants were found at all life stages suggesting that these long-distance dispersal events occurred over multiple events and are a regular phenomenon rather than a process limited to chance," the researchers wrote. "Additionally, we identified individuals with mixed north-south genotypes in both regions demonstrating social and reproductive integration of migrants into local breeding populations."
It also appears that the fish migrate while they are still in their larval stage, which makes it amazing because they were able to travel the great distance given that they only measure less than one centimeter long. The researchers believe that the fishes were likely riding the ocean current to assist them with their long journey.
"There are only two coral reef systems along this coast, and they are separated by 400 km of surf beaches," Simpson said. "In order to persist as a single species, we know Omani clownfish fish must occasionally migrate between these two populations."
