Clownfish babies are able to travel great distances, just like the storyline of the movie Finding Nemo. The young fish are able to migrate for hundreds of miles through the ocean, moving to different locations from where they were born.
Clownfish usually spend most of their lives within the protective tentacles of sea anemones, but researchers have predicted before that the young creatures might move to new homes. This was the first time that such an exchange has been witnessed in the wild.
Researchers were able to measure the birthplaces of Omani clownfish in the wild, and compare those findings to the location where the animals were found. They found that six percent of the fish had traveled 250 miles or more from where they were born.
"This is an epic journey for these tiny week-old fish," Steve Simpson, senior lecturer in marine biology and global change at the University of Exeter, said. Simpson believes the fish ride on the current of the ocean in order to reach great distances, considering they are barely a centimeter long when they begin to embark on their journey.
In the movie Finding Nemo, such long journeys are told to take place during the larval stage of the species.
Simpson and his team led a study, collecting clownfish from waters around southern Oman.
"The southern coast of Oman is relatively isolated from the rest of the Arabian Peninsula so you find a lot of species there that you wouldn't find anywhere else in the world," Simpson told the press. "There are only two coral reef systems along this coast, and they are separated by [250 miles] of surf beaches."
Migration between these two reef systems is crucial for the Omani clownfish to survive as a species.
Researchers captured 400 live clownfish for the study, and removed a small portion of their fin for DNA analysis. The animals were then released back into the water, to live out there lives. They found that a majority of the animals traveled from north to south, suggesting prevailing currents may play a role in the dispersion of the species. To test this idea, researchers created an oceanographic model of the local water. The results were consistent with ocean currents, driven by winter monsoons, directing migration of the tiny fish.
Hybrid fish, conceived from matings between fish from both populations, showed the migrants reproduced after traveling to their new homes. This showed reproduction was affected by the migrations. Such travel could serve to add diversity to populations.
Omani clownfish larvae migration was detailed in the online journal Plos One.
