Crystal and her Water Beetles


[Emily] Hey! We’re here with Crystal, back at the field museum Crystal, what is it that you do here? [Crystal] I am the Collection Manager of Insects at the Field Museum of Natural History [Emily] You’re an entomologist
[Crystal] I am!
[Emily] You study insects [Crystal] Yeah!
[Emily] What is your area of focus? [Crystal] So, I study water beetles, specifically I study a group called the Riffle Beetles And the Riffle Beetles are the greatest beetles on Earth (Emily laughs) [Emily] You don’t seem… You don’t think that might be a bit of a biased statement?
[Crystal] I don’t [Emily] What’s so great about Riffle Beetles? Also, when ever I hear the word “Riffle Beetles” I feel like there should be a guitar riff, like a (imitates guitar riff)
(Crystal laughs) [Emily] Beetles! [Crystal] Riffle Beetles live underwater and they carry a bubble of air with them and they hold that air bubble for the rest of their life [Emily] Really!?
[Crystal] And that can be up to five years or so [Emily] You put me underwater with one bubble, I’ll probably die [Crystal] Part of it is that they’re so tiny, that they’re actually able to use some of the natural properties of water in order to breathe There’s lots of different kinds of air in the air bubble, There’s oxygen, there’s carbon dioxide, there’s nitrogen And as they use the oxygen in the air bubble, The pressure of the oxygen goes down and it’s less than is in the surrounding water, And so oxygen passively diffuses back into that air bubble [Emily] Whaaaaaat? [Crystal] So, as they use oxygen and give off carbon dioxide in the air bubble, The concentration of the carbon dioxide in the air bubble increases compared to the surrounding water The carbon dioxide then diffuses back out into the water [Emily] What would be the evolutionary imperative for an organism to want to undergo so many adaptations that allows this to happen? Like what’s so great about living in the water? Why do the beetles want to–
[Crystal] This is why I work on water beetles!
(Emily laughs) [Crystal] It was just an empty niche There was nothing there. There were no beetles living there
[Emily] Yeah [Crystal] And nothing eating the periphyton and so these beetles, I guess, saw that as an opportunity And they went underwater And what’s actually cool is that there’s closely related groups That will go into the water but they won’t stay underwater
[Emily] Oh! [Crystal] So, you can kind of almost see that gradient from life entirely out of water to a life entirely underwater Where they never leave [Emily] Yeah. It reminds me of, like, whales, you know, coming– Ancient relatives of whales– came out of the ocean and then at some point They were like, “you know, wasn’t so bad in there” [Crystal] Right!
[Emily] And then they like
[Crystal] Exactly!
[Emily] Evolved to go back to the ocean [Crystal] Exactly! And what’s really cool is that you can see this happen over and over and over again in the Riffle Beetles [Emily] You were just on a collecting trip to New Zealand [Crystal] I was! We collected all around the south island, so we traveled from stream to stream Sampling each stream looking for different populations of water beetles [Emily] Why is it so important to go to so many different streams, Like why don’t you just go to one New Zealand stream and “oh, that’s good” [Crystal] Because every stream has a different population So, you can imagine a watershed, it’s like a hand, with lots of little fingers that come out And each of those little fingers is a stream and they all come together into one larger stream and that’s a watershed. You might have another watershed over here, maybe there’s a mountain in the middle And those two are separate And so, they might have separate evolutionary paths So, what we can do is we can study all those populations We can study their morphology, so, how they look. We can use their DNA to try to figure out how they’re related, How far into the past or how deep into the past they separated, So, you might be able to match that up with different geological events [Emily] You mentioned how important water beetles are for learning about the health of New Zealand streams But, they also live all over the world [Crystal] Actually, we know a lot more about the water beetles in the US than we do about the water beetles in New Zealand In fact, we had a curator here named Harry Nelson who worked on the same group of water beetles that I do And he geo-referenced every place he collected on a map This is just an example of one of the maps that Harry Nelson had put together And what’s really cool about it is he actually outlined all of the watersheds in Illinois on this map in different colors And now, we can actually use Geographic Information System, or GIS, we can use Google Earth In fact, you can go on Google Earth right now and you can put all of your collecting localities on Google Earth right now [Emily] Oh!
[Crystal] If you really wanted to
[Emily] That time I found a dead raccoon on the side of the road and brought it in? [Crystal] Put it on the map!
[Emily] Yeah! [Emily] Streams are super important environments, and when I think of, like, when you’re trying to conserve an area A lot of times streams are kinda neglected You know, you can put a border around a national park or a protected area But the stream goes in and and the stream comes out And there are opportunities for invasive species and pollution to, like, go into that stream Are water beetles another one of those bioindicator species? [Crystal] They are! They actually make a pretty good bioindicator, because a lot of species of Riffle Beetles At least, we’ve seen in North America, that a lot of species of Riffle Beetles Will be sensitive to things like paper-mill pollution, Rayon-plant pollution, changes in pH, It’s nice to conserve them for their inherent value, like, “Oh, this is a species of water beetle that only lives in this stream or watershed” But, really we can use them as a tool to determine water quality [Emily] You were obviously super stoked about seeing all these water beetles in New Zealand Was there anything else that you saw that was also really exciting? [Crystal] Yeah! So, one of my favorite insects that I saw in New Zealand, it’s called the Blepharcerid [Emily] What?
[Crystal, slowly] Blephariceridae [Emily] Blepharcerid
[Crystal] There you go [Emily] Sounds like someone sneezed, like (imitates sneezing) [Crystal] These Blepharcerids are a type of fly and they’re unlike any fly you’ve ever seen before Their larvae actually live in the coldest, cleanest, most riffily streams there are, so right where you find Riffle Beetles [Emily] Oh!
[Crystal] What they do is they’ve got little suction cups on their body and they suction cup to rocks in streams What’s really fun is that when you’re collecting in the stream, you’re disturbing all the critters in the stream And what happens is they get disturbed too and then they float off and then they stick to your legs [Emily] The little suctions!
[Crystal] And you have little suctions cups sticking to your legs, it’s really cute [Emily] It sounds like an adorable maggot [Crystal] It’s an adorable maggot [Emily] ‘Cause that’s what they are! They’re fly larvae
[Crystal] That’s their new common name: The Adorable Maggots [Emily] The Adorable Maggots, I like that.
[Crystal] If I had to work on a fly, I would work on Blepharcerids [Emily] Yeah, I think I would too I probably… There’s probably no chance I’ll do that, but I’ll just look at pictures of them [Crystal] Okay
[Emily] Little videos Transcribed by Ethan M.

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