• picture
  • picture
  • picture
  • picture
Public Radio's Environmental News Magazine (follow us on Google News)

Emerging Science Note/Genderbending Aquatics

Air Date: Week of

stream/download this segment as an MP3 file

Living on Earth’s Cynthia Graber reports on a new discovery about why clownfish sometimes change their size and sex.


ROSS: Coming up: a journey to the bottom of the Black Sea. First, this Note on Emerging Science from Cynthia Graber.


GRABER: If the animated film character Nemo were a real fish, he might not stay a boy forever. That’s because Nemo is a clownfish, and clownfish can change sex at different points in their lives. Scientists have been on to this phenomenon for years. They also knew that clownfish can change size, even after reaching adulthood – but they didn’t know why. Now one scientist says he has an answer.

Peter Buston of Cornell University spent a year in Papua New Guinea, diving four to six hours a day tracking clownfish. Buston noticed that within each group of fish that live together in a sea anemone, there are two breeders, the female being slightly larger than the male. Then there are three or four non-breeding clownfish, each getting progressively smaller down the hierarchical line. Buston discovered that when one of the breeders dies, each fish moves up the ladder. If the female dies, the breeding male grows larger and becomes a breeding female. Then the largest non-breeder morphs into a breeding male.

Buston says the little clownfish stay little because if they grew large, the breeders might see them as a threat and force them out of the protective anemone. So, as far as clownfish go - sometimes it’s better to be a small fish in a big pond.

That’s this week’s Note on Emerging Science, I’m Cynthia Graber.

ROSS: And you're listening to Living on Earth.

[MUSIC: Wes Montgomery “Movin’ Wes’, Pt. 1” Compact JazzPolygram (1987)]



Living on Earth wants to hear from you!

P.O. Box 990007
Prudential Station
Boston, MA, USA 02199
Telephone: 1-617-287-4121
E-mail: comments@loe.org

Newsletter [Click here]

Donate to Living on Earth!
Living on Earth is an independent media program and relies entirely on contributions from listeners and institutions supporting public service. Please donate now to preserve an independent environmental voice.

Living on Earth offers a weekly delivery of the show's rundown to your mailbox. Sign up for our newsletter today!

Sailors For The Sea: Be the change you want to sea.

Creating positive outcomes for future generations.

Innovating to make the world a better, more sustainable place to live. Listen to the race to 9 billion

The Grantham Foundation for the Protection of the Environment: Committed to protecting and improving the health of the global environment.

Energy Foundation: Serving the public interest by helping to build a strong, clean energy economy.

Contribute to Living on Earth and receive, as our gift to you, an archival print of one of Mark Seth Lender's extraordinary wildlife photographs. Follow the link to see Mark's current collection of photographs.

Buy a signed copy of Mark Seth Lender's book Smeagull the Seagull & support Living on Earth