(Photo courtesy of NOAA)

CURWOOD: I understand that the toadfish has a pretty impressive mating ritual. Can you describe that?

WANG: A male fish usually puts on very elaborate dances or changes color to win over females. Now, the midshipman male cannot dance and have no scales to change color. So it prefers not to be judged by its looks -- it actually resorts to singing to lure females.

CURWOOD: Well, lets take a listen to that sound right now.

[LOUD, VIBRATING HUM ]

CURWOOD: You know, if I heard that I wouldn’t think it was a fish. In fact, as I understand it, when people were trying to figure out this strange noise on the California coast they thought that maybe aliens were landing or some power plant had gone out of whack. I guess these toadfish have made quite a reputation for themselves.

WANG: Yeah, because the sound, the humming sound, sounds so much like man-made machine noise many residents suspected secret underwater military operations. So I think in 1977, through some very ingenious detective work, by an acoustic engineer and his friends, the secret agent man turned out to be this lonely toadfish in heat [laughs]. So now the community actually welcomes the summer residents by sponsoring annual humming toadfish festivals.

CURWOOD: Now, what about the mechanism? What have you discovered about the mechanism of making this sound by the fish?

WANG: It turns out the male has an air bladder which looks like an elastic balloon, but with two pieces of muscle attached to the surface. Now, these muscles are called drumming muscles because the vibration of these muscles changes the volume of the air bladder and therefore creates the soundwave. And it vibrates about a thousand times a minute. And this is easily rivaling the speed of, say, hummingbird wing beat frequencies or the speed the rattlesnake actually rattles its tail. The most amazing part of this is that the male can actually sing for a very long time. They can sing up to an hour or more without stopping.

CURWOOD: Wow.

WANG: That’s the amazing part.

CURWOOD: So, I’m just wondering where this research might wind up. I’m wondering how likely is it that from this understanding of the toadfish muscles that we could make, say, heart muscles stronger, or make humans super strong.

WANG: Actually, yeah. The special feature here is really a combination of the speed as well as endurance. So we think if we can understand the mechanism with which these structures assemble, we’ll actually be able to do reverse engineer these properties into human tissue, to coach some of the muscles in humans to work either faster, or work longer, or both.

CURWOOD: Kuan Wang is chief of the Laboratory of Muscle Biology at the National Institute of Arthritis and Muscularskeletal and Skin Diseases. Dr. Wang, thank you for taking this time with me today.

WANG: You’re very welcome. Thank you.

CURWOOD: Coming up: Yes, we have no bananas – but we do have a story about how this fruit became the world’s most successful crop and efforts underway to keep it from going extinct. Stay tuned to Living on Earth.

[MUSIC: Nickel Creek “Reasons Why” NICKEL CREEK (Sugarhill – 2000)]