The Coffinfish Holds Its Breath for Up to Four Minutes

Chapters

1. 0:00 A fish that is not breathing
2. 0:29 The one thing a fish cannot stop doing
3. 0:56 EX1806, dive four, Blake Escarpment South
4. 1:21 Down to 1,310 metres, 4.1 degrees
5. 2:15 Bathyal steppes
6. 3:33 15:26 UTC: is this a Chaunax?
7. 4:30 What you are looking at
8. 5:49 He is already inflated
9. 6:42 Fifteen centimetres
10. 7:25 Nine and a half minutes on camera
11. 8:22 How a fish breathes
12. 9:09 Fifty-three breaths a minute
13. 9:35 What pumping costs
14. 10:27 The goosefish, and the slowest breath measured
15. 12:04 Slow is not the same as stopped
16. 13:25 Two people, a desk, and the archive
17. 13:49 Eight fish, timed
18. 14:33 Thirty percent
19. 15:20 The museum and the CT scanner
20. 16:28 One small pore
21. 16:47 Why: money or armour
22. 18:05 The body that spends nothing
23. 18:49 Did this one hold its breath?
24. 19:13 The outline, measured
25. 20:13 What is still open
26. 20:40 Three names, one fish
27. 21:08 What the record holds
28. 21:52 Next: the promise gets kept

Transcript

A fish that is not breathing 0:00

Thirteen hundred metres down, off the coast of Georgia, a robot has stopped in front of a fish. The fish is red, about the size of a hand, and it is sitting on the mud on its fins. Watch it. It is not swimming. It is not walking. And if you look at the side of its head, where the water should be going in and out, nothing is going in and out. For as long as this camera stays on it, this fish will not take a breath.

The one thing a fish cannot stop doing 0:29

That is not supposed to be possible. A fish has to pump water across its gills, all the time, or it suffocates. Keeping that water moving is the one thing a fish cannot stop doing. This episode is about the family that stops, the two people who timed it on public video, and the museum specimens that explained how. Every number comes from the dive log, the paper, or the frame in front of you.

EX1806, dive four, Blake Escarpment South 0:56

The dive is EX eighteen-oh-six, dive four. NOAA Ship Okeanos Explorer, the expedition called Windows to the Deep twenty-eighteen. Seventeenth of June. The site is Blake Escarpment South, about four hundred kilometres out from the Georgia coast, on the outer edge of the Blake Plateau. Thirty point nine four north, seventy-seven point three three west.

Down to 1,310 metres, 4.1 degrees 1:21

The vehicle goes into the water at twelve twenty-four UTC and touches bottom at thirteen twenty-eight, at thirteen hundred and ten metres. The water there is four point one degrees Celsius, measured by the vehicle's own sensor. The pressure is about a hundred and thirty times what it is at the surface. The vehicle will stay on the bottom for five hours and fifty-three minutes.

On the way down, the vehicle's sensors catch something. At about eight hundred and eighty metres the temperature drops sharply and the oxygen jumps, and right at that boundary the water is thick with particles. Marine snow. Dead plankton, faecal pellets, mucus, drifting down. The team will come back to that layer on the way up and spend two hours in it. Keep it in mind. It is the reason there is anything to eat down here at all.

Bathyal steppes 2:15

The plan for the day is geology and coral. This part of the slope steps down in terraces, from twelve hundred to fourteen hundred metres, and nobody had put a camera on them before. The team calls them bathyal steppes. Broken rock with a thin skin of sediment, and every hard surface colonised by something.

Black corals at the base of the scarp. Bamboo corals at the crest. Seven kinds of black coral tentatively named on this one dive, plus octocorals, stony corals, glass sponges, squat lobsters riding on the branches. The summary calls it the highest coral diversity of the expedition so far. The fish is not in the plan. The fish is never in the plan.

Who else lives here. Cutthroat eels, the long grey ones that drift through almost every deep dive on this coast. A cusk eel. A bobtail squid, buried to the eyes in sediment at the foot of a stony coral. A dandelion siphonophore, tethered to the mud by threads. A golden crab the size of a dinner plate, near the top of the scarp. Everything you see for the next twenty minutes is from this one dive, and it is all credited on screen.

15:26 UTC: is this a Chaunax? 3:33

Fifteen twenty-six UTC. The vehicle is climbing a slope of about thirty degrees, and the geologist on watch is explaining the terraces. Then somebody on the console sees a small red shape on the sediment, next to a pale block of rock. Here is the room, at the moment it happens.

Chaunax. A sea toad, or coffinfish. Family Chaunacidae. They are anglerfishes, cousins of the deep-sea anglerfish everybody has seen a drawing of, but these ones live on the bottom, not in open water. And the room has an eye for them, because one of the scientists has collected one before, at a site called the Charleston Bump.

What you are looking at 4:30

Here is what you are looking at. A balloon-shaped body tapering to a small tail. Loose, rough skin, covered in tiny spine-like scales. A big eye with an orange ring. And on top of the head, between the eyes, a short rod with a mop of flesh on the end. That is the lure. The fish keeps it folded into a groove and flicks it out over its mouth when something small comes close.

The fins under the body are not for swimming. They are modified into something closer to feet. Sea toads walk. They push themselves across the bottom, and, as the room says, they use the fins to hold themselves up off the sediment. This one is doing exactly that. It is standing.

The family lives on shelf and slope, from ninety metres to more than two and a half thousand, in every tropical and temperate ocean. Two genera. And for most of the time science has known about them, it knew them from trawl nets, dead on deck. One of the two genera was not seen alive at all until two thousand and two, when a robot met one on a seamount off California. Which is to say, almost everything anybody knows about how these fish behave was learned in the last twenty years, on camera.

He is already inflated 5:49

And then, about two minutes into the encounter, one of the scientists says the sentence this whole episode is built on. Listen to the last part. He is already inflated.

So the room knows something in June twenty-eighteen. They know that sea toads lie flat on the rock, and that when they are disturbed they suck in water and swell up. They have seen it on other dives. They even have a specimen that stayed inflated all the way up to the surface. What nobody in the room says, because nobody knew it yet, is how long the fish keeps that water in.

Fifteen centimetres 6:42

They put the lasers on it. The two red dots on the Deep Discoverer are ten centimetres apart, and that is the only ruler down there. Here is the room measuring it.

Fifteen centimetres. When it fills the whole screen it reads like a football, and it is the length of a pencil. That last remark is worth keeping. He is trying to make himself look big. It is a hypothesis, offered live, and it is one of the two that the paper will take seriously.

Nine and a half minutes on camera 7:25

Now the part that only the archive can show you. The fish comes into frame at fifteen twenty-six and twenty-four seconds UTC. The vehicle moves around it, zooms in, pulls back, zooms in again, puts the lasers on it, and goes back to the rock beside it. The fish is still there at fifteen thirty-six. Nine and a half minutes on camera. It does not move once.

The log for those five minutes, typed on the ship as it happened, reads like this. Chaunax. Sea toad. Pink frogmouth. Redeye gaper. Four names for one fish, which tells you how many people have met this family under how many circumstances. The written summary that evening gives it half a line. An anglerfish, Chaunax, was observed on soft sediment. That is the entire official account. The rest is in the video.

How a fish breathes 8:22

To understand why that is strange, you need to know what a fish is doing when it looks like it is doing nothing. Water holds a small fraction of the oxygen that air does, and it is far heavier to move. A fish cannot breathe the way you do, with one expanding cavity. It pumps. Two pumps, in fact, working out of phase.

The mouth cavity expands and draws water in. Then it closes and squeezes, and the water is forced back across the gills. Behind the gills, the chamber under the gill cover expands at the same moment, sucking the water through, and then it pushes it out. Mouth pump, gill cover pump. Suck and squeeze, suck and squeeze. It never stops.

Fifty-three breaths a minute 9:09

How often? A rainbow trout at rest, in fifteen degree water, has been measured at fifty-three breaths a minute. Just under one a second. A fast swimmer can stop pumping and simply hold its mouth open, letting its own speed push water through. That is called ram ventilation, and it is the only known way a fish gets to stop pumping. It has to keep swimming to do it.

What pumping costs 9:35

Pumping costs something. How much has been argued over for fifty years. One careful measurement, on a sharksucker that can switch between pumping and ram ventilation, put the cost of pumping at between three point seven and five point seven percent of its resting oxygen use. Rainbow trout, switching to ram ventilation mid-swim, saved ten percent. Older estimates in the literature run as high as forty-five.

Take the small number. Four or five percent of everything you burn, spent just on moving water over your gills, every second of your life. For a fish in warm water with food around, that is a rounding error. For a fish sitting at four degrees, thirteen hundred metres down, where a meal may not walk past for days, it is a line in the budget worth cutting.

The goosefish, and the slowest breath measured 10:27

The anglerfishes had already found part of the answer. The goosefish, a shallow-water cousin the size of a doormat, has one of the slowest breathing cycles ever recorded in a fish. A single cycle takes more than ninety seconds. Stacy Farina measured it, in twenty-sixteen, with live goosefish in a tank.

The expanding phase alone lasted between sixty-two and a hundred and twenty-seven seconds. The gill chamber opens so slowly that from above you cannot see it move. And when the fish was disturbed, it sped up. The same phase dropped to eighteen to thirty seconds. Slow when calm, faster when bothered. But it never stopped. The water was always moving.

That paper also killed an older idea. It had been claimed that goosefish do not use their jaws or gill covers to breathe at all, that the whole cycle ran on some other mechanism. Filmed properly, the skeleton moved exactly like any other ray-finned fish. Just very, very slowly. Slow is not the same as stopped. Nobody had seen stopped.

Every anglerfish carries the same basic kit. An enlarged fan of bones under the throat, the branchiostegal apparatus, and a gill opening squeezed down to a small hole. That is the standard lophiiform arrangement, and the goosefish uses it to breathe slowly. The sea toads, it turns out, use the same equipment to do something nobody had seen the equipment do.

Slow is not the same as stopped 12:04

So here is the trap, and it is the reason this took until twenty-nineteen. If a fish breathes once every two minutes, and the movement is almost invisible, how do you tell that from a fish that is not breathing at all? You cannot, from one frame. You cannot from a minute of video. You need a fish that stays in shot for a long time, and you need to know what to watch for.

What you watch for is the exhale. When a sea toad finally lets the water go, the body visibly deflates, like a bag being let down. It is not subtle. Farina has posted a clip of exactly that, from another NOAA dive, and captioned it one way to lose a lot of weight. Between two of those events, if the chamber stays full and nothing goes in or out, the fish is holding its breath. And you can put a stopwatch on it.

And the paper did not start from the video. It started from a prediction. Deep-sea habitats favour animals with low energy demands, the authors wrote, so deep-sea fishes should show specialisations, in behaviour and in anatomy, that cut the cost of pumping water over the gills. Then they went looking for a fish that would show it. Sea toads were the obvious candidate. Nobody had watched one long enough.

Two people, a desk, and the archive 13:25

The two people who did were Nicholas Long, an undergraduate at Dickinson College in Pennsylvania, and Stacy Farina, the goosefish biologist, by then at Howard University. They did not go to sea. They went to the same archive this channel uses. NOAA's dive video is public, and it is full of sea toads that nobody had watched for long enough.

Eight fish, timed 13:49

They found eight individuals, from expeditions in the Atlantic and the Pacific, that stayed in frame long enough to time. And the numbers came back like this. Ventilation rates between zero point zero three hertz and zero point zero zero four hertz. That is one breath every thirty-three seconds at the fast end, and one every four minutes at the slow end.

Between breaths, with the gill chambers full, they saw no inhalation and no exhalation for periods of twenty-six seconds to two hundred and forty-five seconds. Four minutes and five seconds, at the longest. The paper's own words. This holding breath behaviour has not been observed in any other fishes.

Thirty percent 14:33

And the inflation is not cosmetic. From the video, the body volume goes up by as much as thirty percent when the chambers fill. Farina's comparison, in an interview, was a human inflating their lungs until they filled the entire abdomen. That is the shape you have been looking at. The fish in front of you is round because it is full of water.

The one breath every four minutes comes from timing. The thirty percent is estimated from the same videos, the fish before and after it lets the water go. Both numbers are from public video, made by a government robot, read by two people at a desk. Anyone can go and check them. That is the point of this channel, and it is also the point of that paper.

The museum and the CT scanner 15:20

Video tells you what the fish does. It cannot tell you how. For that, Long and Farina went to the Museum of Comparative Zoology at Harvard, to specimens in the museum collection, dissected them, and put them through a micro C T scanner.

Every ray-finned fish has a fan of bones under the throat called branchiostegal rays. They stiffen the floor of the gill chamber. In a trout they are slim and short. In a sea toad they are enormous, and the muscles that spread and close them are built to match. That is the hardware. A gill chamber that can hold a third of the animal's volume, and a frame strong enough to keep it closed.

Farina's summary of the scans was blunt. The largest gill chambers relative to body size that we have ever seen. And she was clear about what that meant for the record. This is a unique behaviour for water-breathing fishes. It is the only case we have ever seen. A biologist who had spent years timing the slowest breathers in the sea, saying she had never seen one stop.

One small pore 16:28

And the exit is tiny. On a sea toad, the gill opening is not a slit behind the head. It is a single small pore, above and behind the base of the pectoral fin. A pore that small leaks slowly, and a chamber that big holds a lot. That is the whole trick.

Why: money or armour 16:47

Why do it. The paper gives two reasons, and it is careful to say which one it believes more. The first is money. If pumping costs a few percent of your energy, and you pump once every four minutes instead of once a second, you have cut that line of the budget by a factor of a couple of hundred. In a place where food is the scarcest thing there is, that is not a trick. That is a strategy.

The second reason is the one the room offered live. He is trying to make himself look big. A round fish is harder to swallow than a flat one. The paper compares it to a pufferfish, and then points out the difference. A pufferfish fills its stomach. A sea toad fills the chamber behind its gills. Same result, from completely different plumbing.

The authors lean towards the energy explanation, and their reason is practical. A chamber full of water is a poor shield, because a bite would simply let the water out. And the fish in the videos are not being attacked. They are sitting alone on the bottom, inflated, for minutes at a time, with nothing near them but a robot. Defence is something you do when a threat arrives. This looks like something they do all day.

The body that spends nothing 18:05

So add it up. This is an animal at thirteen hundred metres and four degrees, in water with plenty of oxygen but almost no food. It has given up swimming, and walks. It has given up chasing, and fishes with a lure. And it has given up the one thing every other fish keeps doing from the moment it hatches. It stops breathing, and it waits.

Long put it this way. They have completely adapted to be a seafloor animal. They hardly ever swim. Some people call them lazy. That is the wrong word. Lazy is spending less than you could. This is spending exactly what the place allows, and not one breath more.

Did this one hold its breath? 18:49

Now, back to the fish on this dive. Did this one hold its breath? Honest answer. We cannot see its gill opening at this resolution. NOAA publishes the dive video at six hundred and forty pixels wide, and a pore the size of a pencil tip does not survive that. So we did the only thing the frame allows. We measured the outline.

The outline, measured 19:13

For a hundred and thirty-seven seconds of close-up, the red silhouette of this fish does not change shape. No visible swelling. No visible collapse. No exhale of the kind Farina filmed. That is consistent with a fish holding a full chamber for the length of the close-up. It is also consistent with an exhale too small to see at this size. We do not know which. The eight fish in the paper were timed. This one was filmed.

What it would take to know is not exotic. It would take a robot parked in front of a sea toad for ten minutes, at full resolution, with the lasers on and the camera pointed at the side of the head. The vehicle on this dive had the fish in frame for nine and a half minutes and spent most of them on the rock beside it. That is not a complaint. The rock was the plan. But the next time one of these sits still in front of a camera, this is what to watch.

What is still open 20:13

What is still open. Nobody has measured the oxygen inside the chamber while the fish holds it, so nobody knows how much of that water it actually uses. Nobody knows the real maximum. Two hundred and forty-five seconds is the longest of eight, on video that happened to be pointed at the right animal. The true record is somewhere out there on a hard drive, or on a fish nobody has filmed yet.

Three names, one fish 20:40

And nobody in this room knew the species. The log says Chaunax. The written summary tries a species name, and the name it picks belongs to a fish described from the Pacific. The scientist on the console says it does not look exactly like the one they caught. This channel keeps it at family. Chaunacidae, sea toad, filmed at thirteen hundred metres on the seventeenth of June twenty-eighteen. That is the complete honest label.

What the record holds 21:08

Here is what the record holds. A dive summary that lists the anglerfish in one line, between a cusk eel and the midwater transects. A granule annotation that says Chaunax, sea toad, pink frogmouth, redeye gaper. Ten minutes of video in which a fish does nothing. And a paper, a year later, explaining that doing nothing was the discovery.

The last word goes to the room. Two minutes after the fish comes into frame, with the lasers on it, somebody says this. When he takes up your whole screen, you think he is a couple of feet long. Fifteen centimetres. Holding its breath. Waiting for something to walk past.

Next: the promise gets kept 21:52

One more thing. Five episodes ago this channel promised you the dive that forgot to bring a biologist, February nineteen seventy-seven, the Galapagos Rift, the discovery of hydrothermal vents. It was postponed because the nineteen seventy-seven film is not public, and the condition to bring it back was a modern NOAA dive on the same vent field. That dive exists. Twenty eleven, Okeanos Explorer, twenty-five hundred and sixty metres. Next episode, the promise gets kept.

Description and sources

A fish has to keep water moving over its gills, all the time. Sea toads, family Chaunacidae, do not. In 2019 Nicholas Long and Stacy Farina timed eight of them on open NOAA dive video: gill chambers full, no inhalation and no exhalation for 26 to 245 seconds, body volume up by as much as 30 percent. Micro-CT of museum specimens showed the hardware -- enormous branchiostegal rays and the muscles that close them. On this dive the control room described the inflation live, measured the fish with the lasers, and offered the defence hypothesis on the recording, a year before the paper. What nobody did was time it.

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Read This Dive, Vol. 01 — the method, and five dives read with it

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PRIMARY SOURCES

• Long, N.P. & Farina, S.C. (2019). Enormous gill chambers of deep-sea coffinfishes (Lophiiformes: Chaunacidae) support unique ventilatory specialisations such as breath holding and extreme inflation. J. Fish Biol. 95(2): 502-509. doi:10.1111/jfb.14003
• NOAA Ocean Exploration, EX1806 dive 04 ROV dive summary, 17 June 2018: https://oer.hpc.msstate.edu/okeanos/ex1806/EX1806_DIVE04_20180617_ROVDiveSummary_Final.pdf -- bottom time, 1,321 m, 4.09 C.
• NOAA Ocean Exploration, Windows to the Deep 2018, daily update 17 June 2018: https://archive.oceanexplorer.noaa.gov/okeanos/explorations/ex1806/dailyupdates/june17/june17.html -- 30.940 N 77.328 W.
• NOAA NCEI geoportal, granule EX1806_DIVE04_20180617T152500Z_ROVHD and following -- keywords CHAUNAX; SEA TOAD; PINK FROGMOUTH; REDEYE GAPER. Every depth and timestamp here.
• NOAA ROV Deep Discoverer, lasers 10 cm apart: https://oceanexplorer.noaa.gov/technology/subs-deep-discoverer/
• Farina, S.C. & Bemis, W.E. (2016). Functional morphology of gill ventilation of the goosefish, Lophius americanus. Zoology 119: 207-215 -- cycles over 90 s; phase 1 of 62-127 s, 18-30 s when disturbed.
• Altimiras, J. & Larsen, E. (2000). Non-invasive recording of heart rate and ventilation rate in rainbow trout. J. Fish Biol. 57: 197-209 -- 53 breaths/min at rest, 15 C.
• Steffensen, J.F. & Lomholt, J.P. (1983). Energetic cost of active branchial ventilation in the sharksucker. J. Exp. Biol. 103: 185-192 -- 3.7-5.7%; literature 0.5-45%.
• Steffensen, J.F. (1985). The transition between branchial pumping and ram ventilation in fishes. J. Exp. Biol. 114: 141-150 -- trout saved 10.2%.
• Fishes of Australia, family Chaunacidae: https://fishesofaustralia.net.au/home/family/279 -- gill opening a pore behind the pectoral fin; lure stowed between the eyes.
• MBARI (2012), first live observations of Chaunacops coloratus: https://www.mbari.org/news/first-live-observations-of-a-rare-deep-sea-anglerfish/
• Farina and Long quoted from Hakai Magazine, Smithsonian Magazine and National Geographic, 2019; Farina's exhalation clip (NOAA EX1606 footage): https://www.youtube.com/watch?v=evJpHEVQwdo
• NOAA Galapagos Rift Expedition 2011 (EX1103), the next episode: https://oceanexplorer.noaa.gov/okeanos/explorations/ex1103/logs/welcome.html

Abyss Report reads the deep ocean through the record that resolved it -- instrument, date, position and the primary sources above.

About the material. Every moving frame is NOAA Ocean Exploration video from EX1806 dive 04, public domain, credited on screen with dive, depth and position. Three cuts drop the narration and play the original control room audio; each of those windows was re-transcribed in isolation twice and used only where both passes matched. Every diagram is drawn in code from published values. Nothing here is generated.

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