Why The Internet Was Captivated By A Hideous Fish

FLORA LICHTMAN: Last week, a viral video likely floated to the top of your feet. A rare black seadevil anglerfish, which basically looks like a floating head with a frightening amount of teeth and two teeny tiny, cloudy, beady eyes.

It made the news, because it was spotted near the surface close to Spain’s Canary Islands, and usually, anglerfish reside in the deep ocean. So why was she paddling so close to the surface? Was she sick? How unusual is this? Also, why do these fish even look like this? I have a lot of questions.

So we are using this fish hook as an excuse to do an in-depth look at this hideous creature. Here to break down fact from fish-ction is my guest, Dr. Kory Evans, Assistant Professor of Biosciences at Rice University, based in Houston, Texas. Kory, welcome to Science Friday.

KORY EVANS: Thanks for having me.

FLORA LICHTMAN: Kory, as a marine biologist who studies anglerfish, what was your reaction to this video?

KORY EVANS: Yeah, my reaction at first, was I thought it was AI. I remember waking up in the morning and just seeing this video posted without any context on Instagram. And I’m looking and I’m like zooming in really, really close just to make sure that I’m not being fooled.

And I’m looking, I was like, man, the fin motion, this looks like a real fish. But what is it doing here? Why is it bathed in sunlight? These fishes live in the absence of light. They live so deep underneath the ocean, that light doesn’t penetrate. So seeing this fish in broad daylight was super disorienting and confusing.

FLORA LICHTMAN: Why do you think– What’s it like for you to see this huge amount of interest that this little fish has generated?

KORY EVANS: It’s so exciting. And it’s funny, because a lot of folks got really, really excited about it, and then they found out that the fish was about four inches long or something like that. And they were so excited about it.

I thought that was really cool. There’s poems being written about the sad part about this fish finally seeing the light of day and then dying later.

FLORA LICHTMAN: Yeah, let’s hear one.

AUDIENCE: With her final breaths, her little body swam at the possibility just to say goodbye, proving to the world that beautiful things do come from the darkness in which we cannot see.

FLORA LICHTMAN: Would you like, my girl is finally getting the attention she deserves.

KORY EVANS: Exactly. That’s kind of how I felt, yeah.

FLORA LICHTMAN: Why was this fish up there? Do you have any theories?

KORY EVANS: So I think the fish might have been sick. Oftentimes, when fish get sick, they do kind of exhibit weird behaviors. And it can actually kind of become like a runaway effect, as well. As you move from a deep place to a more shallow place, gas will continue to expand, kind of surface faster and faster.

I was surprised, A, that it was so intact that close to the surface, because usually if a fish comes up really fast, it’ll look all disfigured, like our friend, the blobfish. So the fact that this fish was looking good, aside from the fact that it died shortly after, was actually really surprising.

FLORA LICHTMAN: Let me run another theory by you. Could she have been on a hero’s journey to see the light?

[CHUCKLING]

KORY EVANS: I would like to believe that she was on a hero’s journey. There’s been some debate as to whether or not the eyes of an anglerfish can even perceive that much light. But I want to believe that they could.

FLORA LICHTMAN: So obviously, these are really strange looking creatures. For me, they’re hideous. But also, I can’t look away, I’m obsessed. I understand that your research may help explain why anglerfish look this way.

KORY EVANS: Yes, yes. So I was part of this larger research team that was interested in reconstructing first, the evolutionary history of anglerfishes, and then asking the question that we all kind of wondered is, how and why did the deep sea anglerfish get so weird.

FLORA LICHTMAN: That’s a question that the marine biology community wonders about?

KORY EVANS: All the time. And it’s not just anglerfish that are doing this. Lots of fish go deep and get super weird and freaky, and we don’t have a clear answer why.

FLORA LICHTMAN: Well, how did you study that, and what did you find?

KORY EVANS: Yeah. So the first part was building the tree of life or the tree of relationships for anglerfish. And then from there, we ask some questions like, how fast did the traits evolve across this anglerfish group.

And one of the early hypotheses was that maybe the deep sea anglerfish just evolved really, really quickly, and that’s how they got so weird and freaky.

FLORA LICHTMAN: Wait, wait, so are you saying that if you evolve more quickly, you’re more likely to look freaky?

KORY EVANS: It can certainly, it can certainly help you look freaky, yeah. It can get you to a freaky place.

FLORA LICHTMAN: Really?

KORY EVANS: Yeah, especially in fish.

FLORA LICHTMAN: And you evolve quickly because you’re in a really extreme environment? Is that typically why?

KORY EVANS: Yeah. And when you’re in a really extreme environment, I guess the threshold for what works is really, really tight. So you’re really constrained. There are only a few solutions. And if you’re not already there, when you’re in that extreme environment, you really need to get there fast, otherwise you go extinct.

So when these anglerfishes colonize the deep sea, we thought that, OK, maybe we would see really rapid rates of evolution, because this is a really constraining environment.

FLORA LICHTMAN: Is that what you found?

KORY EVANS: No, actually.

FLORA LICHTMAN: What?

KORY EVANS: It was crazy.

FLORA LICHTMAN: This is a plot twist. OK.

KORY EVANS: Yeah, there’s a plot twist. So the pelagic ones that we saw in the video, they’re deep water, but they’re not touching the bottom. They didn’t evolve quickly when they got there. It just seems like they were able to get away with more things.

So when you think about evolution, you’re taught like, oh, it’s a survival of the fittest. But for fish, in my experience, what I’ve learned, is it’s more the survival of fit enough.

FLORA LICHTMAN: That rings true across the animal kingdom, certainly in our species.

KORY EVANS: Yeah. It’s like, I can do this and it doesn’t kill me. And so I can just keep diverging and evolving these weird new adaptations and it’s not counting against me. So it looks like there was a relaxation of constraints, especially surrounding their skull shape and their eye shape and their body shape in these deep sea kind of pelagic anglerfishes.

FLORA LICHTMAN: Because they’re not competing with other animals? Or why would there be fewer constraints in that environment versus another environment?

KORY EVANS: Yeah. It’s possible that there’s less density of fishes, so there’s less competition. The way that they hunt also changes. So anglerfishes aren’t chasing down prey in the water column. They’re just waiting for things to be attracted to their lures, and then they’ll just grab them.

These guys, their whole life is just bobbing around. So you don’t want to expend too much energy, because you don’t know when your next meal is coming, so you want to just make sure you have a big stomach, big jaws and do as little else as possible.

FLORA LICHTMAN: That’s like my ideal lifestyle.

KORY EVANS: Yeah, and that’s the game. And it turns out there’s a lot of ways to do that in anglerfishes. I’ve explored many of them.

FLORA LICHTMAN: OK, so I’ve been watching the TikToks of people crying as they watch this anglerfish video, which may be more of an indication of how we’re all just hanging on by a thread right now.

But it sounds like you don’t think she was risking it all to see the sunlight. Is there another poetic fact you can share about anglerfish that we can tuck into our tackle box, to draw on during dark times?

KORY EVANS: You want poetic facts? I can give you a poetic fact. So when a male anglerfish is born, they don’t grow to be those big kind of toothy jawed females that you see. Instead, the males are usually either smaller or these small little parasitic tadpoles that attach to them.

And when they attach to a female anglerfish, they actually integrate their circulatory system. So the blood that’s circulating through the female will then begin to circulate through the male, and they’ll basically kind of fuse together.

And the female basically uses that male as a sperm sac. So yeah, whenever it’s time to reproduce, they don’t have to look for males, they have them attached so they spawn together that way. So that’s kind of romantic in a way.

FLORA LICHTMAN: I mean, they’re taking co-dependency to another level.

KORY EVANS: Exactly. And sometimes, female anglerfish will have multiple males kind of attached to them as well.

FLORA LICHTMAN: Oh, good for you, girl.

KORY EVANS: I know, good for her, right? And this is just kind of a way to solve that problem of finding a mate in complete darkness.

FLORA LICHTMAN: Kory, I love talking to you about this. Thank you so much.

KORY EVANS: Yeah, anytime.

FLORA LICHTMAN: Dr. Kory Evans is an assistant professor of biosciences at Rice University.

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