IRA FLATOW: Every year tourists flock to the caves of New Zealand to gawk at an amazing sight– thousands of little lights shining in the dark like stars. But they’re not stars or even fireflies. They’re glow worms. And while many people find these creatures enchanting, the truth is–

MIRIAM SHARPE: Technically a glow worm is actually a glowing maggot. But that doesn’t sound as romantic.

IRA FLATOW: No, it doesn’t. That’s Dr. Miriam Sharpe, a researcher who’s studying the New Zealand glow worms, investigating the mystery of how exactly they light up. Turns out we still really don’t know. And Dr. Sharpe and her research partner, Kurt Krause, are the subjects of our latest Macroscope video up on our website at sciencefriday.com/glowworms. And here to tell us more about their research and the weird wonderful worlds of these glow worms is my next guest, Chelsea Fiske, video producer with Moonjelly Productions. Welcome to Science Friday.

CHELSEA FISKE: Hi, thank you for having me.

IRA FLATOW: Does the fact that a glow worm is actually a maggot take all that magic away for you?

CHELSEA FISKE: Not at all. It’s actually kind of funny to learn that. But when you’re there in the middle of a glow worm cave, and you feel like you’re surrounded by 360 degrees of star light, it’s still magical regardless of the fact that they’re actually a fungus gnat.

IRA FLATOW: Because a lot of people remember, I remember as a kid and hearing about glow worms were fireflies that light up outside in the yard. These are not them, right?

CHELSEA FISKE: They are not. So fireflies are in the northern hemisphere. And it’s funny, because fireflies are actually beetles, and these glow worms they’re in the larval stage of a fungus gnat, which is more like a fly. So it can be kind of confusing. But yeah, this species was specific to New Zealand. There’s also a couple of other species in Australia and that’s it.

IRA FLATOW: Tell us about the researchers, the couple of researchers who are investigating the chemistry. What does their research process look like?

CHELSEA FISKE: Sure. So yeah, they were great. Dr. Miriam Sharpe and Kurt Krause. They’re at the University of Otago, which is in Dunedin. So it’s southern New Zealand. And they got into it because they really just wanted to find out what makes these creatures glow. There are about 40 or more different bioluminescent systems throughout the world, and each of them use a different mechanism for glowing.

IRA FLATOW: Hang on. Let me just remind everybody that this is Science Friday from PRI, Public Radio International.

CHELSEA FISKE: Sure. So yeah. So in their research they go out. In this case they go to a ravine near them called Nichols Creek. They go out with their flashlights, or in New Zealand they call them torches, which is more fun. And they take a little shish kebab stick and approach these little glow worms on the walls of the ravine, and they drop them into their tubes to bring back to the lab.

Glow worms are carnivorous and in fact, they can be cannibals at times. So they can’t put too many of them in the same tube. They bring those back to the lab, freeze them, cut off the light organ, which is essentially right at the tail end of the glow worm, and then mash those up into a solution.

And then from there, what they’re really trying to get at is, like I said, figuring out what makes them glow. So they’re separating out the proteins in these light organs to identify the protein or enzyme which they call a luciferase, and then also chemical, a small molecule substrate, or a luciferin. So those two things are the components that they’re looking for that make these bioluminescent creatures glow.

IRA FLATOW: So they just want to know how they work.

CHELSEA FISKE: Yeah, they really do.

IRA FLATOW: They’re not interested in any real application. They just want to figure it out.

CHELSEA FISKE: Right. It’s very refreshing, actually. They’re definitely just in the pursuit of knowledge. And while there are a lot of potential outcomes for this research in biomedical research and various other areas, right now they’re really focused on just understanding and learning.

IRA FLATOW: And the glow worms live in caves. How tough was it filming in the dark like that?

CHELSEA FISKE: Luckily, I love caves. Otherwise it could have presented some challenges. Because, like you mentioned, they’re such tourist attractions. So I was with my husband, Brandon. So we would choose to go at night and oftentimes to the lesser known caves because there are some pretty major commercial caves down there. And so we’d go out at night. Oftentimes these caves are in the strangest places in the middle of a sheep paddock or something.

And so we would take our headlamps. And usually these caves for the glow worms need to be damp. So usually there’s creeks running through these caves. And so we would trek in with our gear and it’s kind of eerie because there are oftentimes eels in the creeks in the caves, which can bite.

IRA FLATOW: Never mind, I’m not going with you.

CHELSEA FISKE: Luckily.

[LAUGHTER]

IRA FLATOW: You didn’t get bit too often.

CHELSEA FISKE: No, not at all. It was completely worth it. It’s magical.

IRA FLATOW: I want to thank you. And it’s up there on our website at sciencefriday.com/glowworms. Chelsea Fiske, video producer with Moonjelly Productions. Thank you very much.

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