Milly: Deep sea flashers

Some brilliant research by Sarah Zylinski that came out of the deep sea research cruise in 2010. Strange to think that even in deep, dark, remote regions, animals still need camouflage...

A link to the paper here.

Milly: Ugly Fish pt 8

Milly: Ugly Fish pt 1
Milly: Ugly Fish pt 2
Milly: Ugly Fish pt 3
Milly: Ugly Fish pt 4
Milly: Ugly Fish pt 5
Milly: Ugly Fish pt 6
Milly: Ugly Fish pt 7

Coming back to my post about pressure (pt 6), how are deep sea animals adapted to survive at depth?

As there are all sorts of animals currently inhabiting the deep, I'll concentrate on fish. Fish are the best anyway. Slightly biased.

Well the problem is, fish don't just have to cope with the crushing pressure (up to 800x greater than at the surface) but the deep is also very dark (beyond 1000m there is negligible surface light) and cold (2°C) making things such as moving around, finding food and reproducing much more challenging. Let's have a look at a few fish and see how they do it. Enter handsome fellow number one, the anglerfish.

Whipnose anglerfish, about the size of a football.
Note the long lure with the tiny esca on the end, capable of bioluminescing.
Image: Dianne Bray

A selection of anglers.
Image: Dr Theodore W. Pietsch and Christopher P. Kenaley

There are 11 families of deep sea anglerfish, some only containing one species, such as the lonely prickly seadevil, Centrophryne spinulosa (Centrophrynidae family) others have many more such as the footballfish, Himantolophidae with 19 species. They are a surprisingly diverse group of ugly fish. As you can see from the pictures above, these animals don't look particularly athletic. If you were to design an animal for a race underwater I doubt 'round' would be the shape you would go for. Nevertheless, these are very successful bathypelagic (1000 - 4000m) animals, but why? Anglerfish are sit and wait predators and with the aid of their bioluminescent lure, can draw in prey such as fish and cephalopods (squid etc) within gobbling distance. The bioluminescent light, which can be controlled producing flashes or sustained glowing is the product of many bioluminescent bacteria that colonise the lure (or esca). They don't even need to feed particularly often since they expend such little energy, evident when you touch one of these animals. Their bodies are both flabby and bony (an attractive combination) suggesting they do very little excercise. Lazy little anglerfish. Not only are they lazy but seriously greedy. An expandable stomach allows anglerfish to munch down prey twice their size. A human man could fulfil his daily allowance of calories with 850g of meat, less than the weight of a mature trout! Seriously rubbish in comparison. 

Sea devil (Melanocetus niger), about the size of a
golf ball, look at that mouth! Image: Milly Sharkey

A female angler with the tiny parasitic male attached.
Image: Dr Theodore W. Pietsch. University of Washington

One problem that could arise, being a voracious predator in the dark munching on anything that moves, is that you might accidentally eat your mate. Finding a mate in the dark expanse of the deep sea is likely to be a very rare event. Some anglers have evolved a bizarre strategy whereby the male does not develop fully, is unable to feed properly and has enhanced olfactory senses (smell). This spurs the male on to quickly find a female before he starves, detecting the pheromones she expels into the water. When they do meet, the male bites the female, releasing enzymes that break down the skin between them, causing the two to fuse. The lucky male is now parasitic and no longer requires digestive organs, brain or his own heart (I told you they were lazy), obtaining everything he needs from the female. In return, he provides her with sperm from his last remaining organ, his gonads, a perfect relationship some may say. Bit clingy, plus he's a bit screwed...sorry I'll stop now.

More later, I need to locate pre-trawl pudding.

Milly: Ugly Fish pt 7

Milly: Ugly Fish pt 1
Milly: Ugly Fish pt 2
Milly: Ugly Fish pt 3
Milly: Ugly Fish pt 4
Milly: Ugly Fish pt 5
Milly: Ugly Fish pt 6

Always dark on the night shift... Image: web

Prepare to commence trawl two. When you have been on a night shift from 4pm to 4am and a trawl is due to hit the deck at 2am, chances are your body clock is going to be a tad confused. Last time I nearly fell asleep in my fish dissection, started writing backwards and couldn’t retain a two digit number in my head for more than 1millisecond. Not doing that again. New tactic! Since I had allocated rest time before the trawl... I decided to stay awake for 28 hours before the trawl, have a sleep then be all fresh and ready for action once the slimy catch was brought aboard. Problem with that is staying awake for 28 hours with absolutely nothing to do tends to send you a bit West. I became inaudible, talking at extremely low baritone frequencies if you can even call it talking, more like incoherent blatherings. The day shift tolerated me well. The rewards were great however, and this time, we were super fish team extraordinaire (well, we functioned without any breakdowns anyhow).




Much like last time, the trawl net was opened (noticeably more rotund this time, a good sign) and catch was spilled into a large bucket ready for inspection. Unfortunately on the last trawl we managed to scoop up a large amount of clinker (burnt coal from steam ships of the past) which made sorting through the cucumbers and delicately removing gelatinous fish nigh impossible. This time, we had little ocean floor debris so I zealously sunk my arms into the cold, slippery assortment of fish, cucumbers and crustaceans and pulled out a big, heavy object. “Oh wow, an exciting find" I thought to myself. “Doesn’t feel like a cucumber, maybe it is a big leathery fish, woohoo!" It was a shoe, a big, woman’s boot. I then proceeded to dig out two bottles and a rock. Thankfully Alan and Juliette were being slightly more sensible and actually searching for fish shaped objects and so commenced a slithery extraction of rattails, smooth-heads, some unfortunate midwater fish and a huge cusk-eel.

Is it a fish?! Is it a holothuriuan?! No. It's a bloody shoe.

Histiobranchus sp., a deep sea eel. Image: Zan 

Cusk-eel! Image: Zan 

 Lovely cusk-eel (Ophidiid). Image: Nina

We had fewer fish this time round, but they were all in really great condition, great for samples we thought, but then memories of hours in the dark surfaced in my brain and I realised that watching 3 horror films to try and stay awake was, perhaps, a terrible idea. Juliette and I managed to put aside a few minutes whilst our fish eyes were on ice to explore the trawl and the sorting process in the wet lab. It looked how I would imagine a backstreet fishmongers from a sci-fi film to look. All manner of strange beasts being weighed and measured and samples for DNA analysis being taken left right and centre. The fish were amazing. There was one fish, aptly named ‘Jellyface’ by Zan, which had a large rounded nose, a small mouth and two, what looked like sensory pits, next to the eyes. The skin on the head felt very bizarre, much like a stubbly beard. The cusk-eel felt even stranger, as you ran your fingers across its skin you felt a crackling sensation which could be due to tiny bubbles under the skin forming as the fish is brought up from depth, decompressing the air within its cells. 

'Jellyface'. Image: Zan

Juliette having a good rummage around in the cucumbers. Image: Nina

Not the most attractive of creatures.
According to one scientist this cucumber is "cute", "look at it's little hat!" she said. I later discovered this 'little hat' is in fact a parasitic anemone. The deep sea is a very strange place! Image: Nina

I had been challenged by one of my supervisors to kiss a benthic fish. Now, he may well have been joking, but I considered this something I should take very seriously and so I sought out the loveliest of all the fish in the catch, the cusk-eel and planted my lips firmly upon its slimy....mouthparts. Picture taken. Job done.

I think the picture says it all. Image: Nina

So why is all of this necessary? Larking about aside, we are taking samples for serious and important science and all possible information is always gathered from these trawls, to make the most of each catch. Stay tuned for an explanation of the science behind the sampling, most likely in the form of an interview with Juliette McGregor (she doesn't know this yet). Roll on the final trawl. Fingers crossed my supervisor doesn’t up the stakes, kissing a benthic fish is one thing, but kissing a sea cucumber, well that's a whole different level of gross.

Milly: Ugly Fish Pt 6

Deep sea Marmite from 7000m

Milly: Ugly Fish pt 1

Milly: Ugly Fish pt 2

Milly: Ugly Fish pt 3

Milly: Ugly Fish pt 4

Milly: Ugly Fish pt 5

Milly: Ugly Fish pt 7

Life on board a research ship can, at times, be rather boring. It is imperative that, to stave off derangement, you make your own fun preferably without damaging yourself or others. We have had a few ideas, after a particularly uneventful evening of mud measuring: 1) Deep sea fish top trumps 2) a horror film featuring a radioactive or chemical spill creating GIANT holuthorians, I'd quite like to call it 'Horrorthurian', not a catchy title and 3) sending weird objects to the ocean floor to see what happens to them.

During my last research cruise Alan very kindly allowed me to place a jar of marmite atop his lander and send it down into the Peru-Chile trench (7000-8000m). Sealed with a plastic top, the marmite was put under an enormous amount of pressure and subsequently its consistency was altered rather dramatically. The top layer became runny like water and at the bottom, set like concrete. I had a great deal of fun digging around in my marmite jar for hours trying to stir it all up whilst an American scientist looked on, grimacing every once in a while when he caught a whiff of its beefy goodness.

So, what does happen to things when they go down the the bottom of the ocean? Well, have a look at this polystyrene cup I put down to 4800m strapped to the lander below. Unfortunately for me, Alan, at 5am, thought it would be really funny if he put it into the bag he had been storing his bait in, before sending it down into the abyss. The reason my cup is now the size of a thimble (and strangely distorted) is due to the effect pressure has on air. Inside the polystyrene lies little air pockets that get compressed with depth, as the pressure increases. The cup is, of course, now also impregnated with mackerel juice, thank you Alan.

My polystyrene cup (left) looking rather distorted and how it looked
 before compression (right)

A previous effort...much better!

Getting slightly more creative....OCUPTOPUS!

Rather boring 'science' bit:

Pressure is measured in pascals (Pa) which corresponds to one newton per square meter (imagine one newton force as the force of the Earth's gravity on an apple). 100kPa (100,000 Pa) is typical air pressure at the surface of the Earth. With every 10m that the cup descends, another 100kPa of pressure is added, constantly squeezing the air into a smaller area until it reaches a point where most of the air is squeezed out of the cup entirely. I've been asked by an alarming number of people whether I will be doing any deep sea diving on this trip. Unfortunately, much like the cup, the air in my lungs would be squeezed out and although this can be rectified by using pressurised air (as with SCUBA diving) to fill up my lungs again, after about 60m the oxygen in the air at high partial pressure would start to poison me, forming reactive species, damaging my cells. Commercial divers are able to reach depths of 100m using gas mixtures with snazzy names like 'hydreliox' (helium, hydrogen and oxygen) or 'neox' (neon and oxygen) which have reduced levels of oxygen and are therefore less likely to cause damage. I say less because there is still the risk of inert gas bubbles forming in the blood or tissues of a diver as they ascend from depth, 'the bends'. It has also been pointed out to me that in carrying enough air for such a trip, I would be squashed like a ripe pear.

At 100m there is 1100kPa of pressure. The deepest living fish ever recorded were at 7.7km (Alan Jamieson, again) where pressure is about 77,500kPa! So how do they survive at these depths under extreme pressure?




I shall explain all in a future post...there is a trawl afoot.

Milly: Ugly Fish Pt 5

Alan with his lander 'Dave', about to be deployed
over the back of the ship. Image: Nina

Milly: Ugly Fish Pt 1
Milly: Ugly Fish Pt 2
Milly: Ugly Fish Pt 3
Milly: Ugly Fish Pt 4
Milly: Ugly Fish Pt 6
Milly: Ugly Fish Pt 7

Things have been relatively quiet over the last few days. No riots here, just high base levels of madness, but then you have to be slightly weird to want to go on a research ship for half of your summer. A few of us have put our heads together and have come up with some ideas for thwarting the violence. We propose the development of a porridge cannon firing hot, sloppy, honey saturated oats. "You would have to counter it with milk and sugar" said one scientist, "they wouldn't expect that". I'm not here to comment on the riots, nor should I make light of the situation but it is very odd reading the updates from sea, it all feels very unreal.

"What exciting thing have you discovered today?!" I imagine my supervisor will be thinking. Well Julian, personally absolutely nothing. I got up, went to the gym then ate a giant plate of shepherds pie and cabbage for breakfast. Proper scientists however have been discovering some really amazing stuff.

Alan Jamieson from Oceanlab, Aberdeen, has sent his lander 'Dave' to the sea floor to photograph the mud (mud again), haha only joking, to photograph the animals! Sorry mud scientists but I've had quite enough of your mud for the time being, especially when there are ugly fish to be photographed!

An Ophidiid, Bassozetus sp., a cusk-eel. Image: Alan Jamieson

An abyssal grenadier (Coryphaenoides armatus) looking rather sad. It must be hard being a deep sea fish.
Image: Alan Jamieson

Nine abyssal grenadiers at the bait. Image: Alan Jamieson

The lander is essentially a large aluminium frame with a number of cameras attached to it, a giant flash and a weight with bait attached to it (more stinking mackerel). It gets sent to the bottom and (hopefully) paparazzis all of the beasties who come to dine at Alan's table. Whilst it may seem relatively easy to chuck a piece of kit over the side to sink to the bottom of the ocean, getting it back is a complicated process. And actually there is no 'chucking' involved, but careful winching and manoeuvring to ensure the lander doesn't get destroyed by the ship's propeller.

To get Dave back (and all of the photos) an acoustic signal is sent from the ship into the water where it travels down to Dave and triggers the release of it's (his?) weights via the movement of mechanical arms. Dave then floats up to the surface powered by the buoyancy of the glass floats attached, where he is collected by the ship! Phew. How on earth this signal manages to travel from the boat all the way to the bottom of the ocean, intact, is beyond me. Mysterious wizardry.

Trawl on Saturday morning, really hope we catch this fella, Bassozetus compressus, the abyssal assfish. Excellent.

Milly: Ugly Fish pt 4

Milly: Ugly Fish pt 1
Milly: Ugly Fish pt 2
Milly: Ugly Fish pt 3
Milly: Ugly Fish pt 5
Milly: Ugly Fish Pt 6
Milly: Ugly Fish Pt 7

Juliette and I digging about in the catch

UGLY FISH! Finally, we have a trawl! Never have I seen so many bizarre looking animals (presuming things that freakish are allowed to be classified as animals) in one place before. Once the catch was hauled on board at about 8am, safely away from the stern that was flying in the air due to the brilliantly timed bad weather, Juliette and I got the first look in (we needed to get fish into the dark asap). That lasted a matter of minutes as a riot from the sidelines began to brew. Reluctantly we brought the catch into the hangar and the feeding frenzy commenced. All scientists descended, franticly digging around in the clinker (burnt coal from back when we had steam ships) pulling out sea cucumbers the size of, well, cucumbers which, in my opinion, fell into three categories. They either looked like bloated sausages, huge purple tongues or like something from the ‘extreme’ section of Anne Summers.

Quickly trying to whisk the fish away before they get exposed
to too much light

A fangtooth, wouldn't call this fish ugly to its face

A bizzarre collection of sea cucumbers.

Scientists went into warp drive, taxonomists started identifying the hundreds of deep sea creatures, geneticists took samples from everything that and one girl Zan after weighing and measuring the fish was even examining their stomach contents. Wonderful, organised chaos.

Sorting through the cucumbers

Looks like a rather disturbing picnic spread.

One of the many crustaceans

that came up with the trawl

Selection of grenadiers

An assortment of slickheads

So in the midst of all of the excitement what were Juliette and I doing? Oh, that’s right, we were barricaded in a blacked out lab with only dim red light to guide us and each other (plus a bag of fish) for company. Since we were under time constraints to get the eyes out of the fish as soon as physically possible I grabbed the first fish out of the bag (an extraordinarily disgusting place to put your hand into, I might add) whacked it on the scales and began the first dissection. Glancing over at Juliette I was slightly worried she might have had a melt down. After the weeks of careful planning and packing, she was finally about to begin the first sample collection, in the dark, likely to take about 12 hours and her legs and arms had frozen in place. Thankfully, the roll of the ship prevented any stationary activity and team fish were off.

With every hesitant poke around in the fish bag, came more gelatinous, benthic beasties. 

About 10 hours later, sleep deprived (after switching from the night shift), stinking of fish, cross eyed and suffering from tunnel vision, Juliette and I emerged triumphant. All fish processed, retinal tissue dissected and placed carefully into various fixes to preserve cells or RNA/DNA.

Apparently there will be another trawl on Friday. God help us.

Thanks Nina and Zan for the pictures!

Success! Sleep deprivation and a very wet arse.

Milly: Ugly Fish pt 3

Milly: Ugly Fish pt 1
Milly: Ugly Fish pt 2
Milly: Ugly Fish pt 4
Milly: Ugly Fish pt 5
Milly: Ugly Fish Pt 6
Milly: Ugly Fish Pt 7

I've just realised it's also unlucky to look at a picture
of a pig. This does not bode well...

It appears we nightshifters are cursed. Possibly because we are a team of 6 women and only one man. Bad luck. Maybe it's because I decided to bring green overalls which apparently make me look like I work in a garden centre, not quite the look I was going for. If this was a commercial trawler I'd have been thrown overboard for wearing green, but I would have had to pass myself off as a man first to step foot on that ship. I've been hearing about all sorts of strange superstitions, an alarming number are pig related. The word pig mustn't be used and if you see a pig on your way to the ship, well, you might as well go home. This all seems to be based on the Garadene swine, the unlucky pigs Jesus cast a load of demons into when he exorcised them from a madman. Oh and then the pigs drowned, so that makes loads of sense. Apparently this is why pigs have so many alternative names, grunter, porker etc. Strange.

Whoops, massive tangent. So the nightshifters on two accounts now have been ready to roll, mud slicing equipment at the ready, and twice the megacorer (mud sampling device) has come back with empty tubes. We have had some fun at 2am prancing around in fishing gear however.

Juliette checking out the amphipod catch

Hundreds of tiny amphipods caught in the baited trap

What have been more successful are the amphipod traps and towed camera, WASP. Amphipods are a bit like marine cockroaches, the crustacean scavengers of the deep. Hugely speciose, they come in all shapes, sizes and colours but one thing they have in common is they all scurry around eating dead stuff. Four traps, baited with possibly the worst smelling mackerel on the planet, were deployed to the bottom of PAP, about 4000m. They came up brimming with amphipods, ready to be barcoded by the geneticists.

Scientists having a gander at the WASP footage

The towed camera WASP (wide area seafloor photography) has been taking pictures of the sea floor as the ship has been sailing along. Makes your average biological transect seem pretty lame, in comparison. This equipment gives scientists a glimpse of what the seafloor looks like without (too much) disturbance. It looks to me like the surface of the moon, covered in hundreds of tracks made by holothurians (sea cucumbers) and a hefty amount of cucumber crap. They are bizarre looking creatures with weird abilities like turning their bodies to liquid to squeeze through gaps or turning themselves inside out to evade predation. But, what they seem to be extraordinarily good at is crapping, and crapping in the most delightful way!

Cucumber crap. Isn't it nice!

On that note I better get some sleep, trawl will be coming up soon and I'm definitely not mentally prepared.

Milly: Ugly Fish pt 2

RRS James Cook

Milly: Ugly Fish pt 1
Milly: Ugly Fish pt 3
Milly: Ugly Fish pt 4
Milly: Ugly Fish pt 5
Milly: Ugly Fish Pt 6
Milly: Ugly Fish Pt 7

We made it! We are on the James Cook, phew.  Since we have been sailing for a few days you might think I'd have worked out where everything was by now but I still end up on the forecastle (I have no idea what that is) deck when trying to find my cabin. Quite a confusing error to make since the forecastle is at the top and my cabin is in the bowels of the ship. My room has no windows which is quite handy as I'm on the 4pm to the 4am shift. So, apparently there is a sauna here but I'm not sure if this is a crew in-joke whereby I turn up at the 'sauna' in a bikini to find that it's actually the engine room.

Tubes of ocean floor

The weather has been extremely good and the boat has been hardly moving at all. I've stayed away from the sea sickness tablets thus far, however there has been mention of 'dreadful conditions' in the next few days and when an experienced deck officer uses the word 'dreadful', you know you're in trouble.

There is an interesting mix of scientists aboard this cruise, exploring the Porcupine Abyssal Plain (PAP). Many people from the National Oceanography Centre (NOC), at Southampton, seem to be interested in mud. Not just the mud, they say, but the wee beasties that reside in it. One important group of organisms are the Foraminifera, or forams for short, strange protists that can be used as indicators of environmental change, as they give scientists an indication of what's happening to the oceans' currents. To study forams, this group are sending a machine, consisting of a frame and 8 tubes, flying the bottom of the Atlantic. When it hits the ocean floor the tubes stick into the mud triggering a mechanism that closes them, then bingo, all you need to do next is drag the thing back to the surface and you have loads of lovely mud!

An unfortunate little sea urchin, captured by one of the tubes

Yesterday I was learning how to slice mud. Easy? No, not easy. For starters it's all carried out in a cold room at 4 degrees, secondly you have to somehow get the mud out of the tubes in some sort of sensible manner so you know what bit you are sampling and thirdly, the mud isn't sloppy, oh no, it's hard like a big rock sausage. Fun though, and now I have something new to add to my CV 'is able to slice deep sea mud'. Tastes nice too.

Carefully removing mud from the tubes

We are currently steaming to PAP and will arrive in an hour or so. There we will be sending down various bits of kit to image the sea floor. As lovely as mud is, I'm excited to see what else PAP has to offer...

(I should also mention that Juliette is still alive)

Milly: Ugly fish

Stomiid. Image: Camilla Sharkey and Julian Partridge

Milly: Ugly Fish pt 2
Milly: Ugly Fish pt 3
Milly: Ugly Fish pt 4
Milly: Ugly Fish pt 5
Milly: Ugly Fish Pt 6
Milly: Ugly Fish Pt 7

When asked about my summer holiday plans recently, I informed my friend that I would be spending a month off the coast of the UK on a months fishing trip. She laughed; I wasn't joking. Come August I'll be up to my ears in gelatinous, benthic fish brought up from thousands of meters and rather alarmingly I've been purchased full body overalls due to the "repulsive stench" of the fish that "never leaves the fabric". I'll be aboard the RSS James Cook for a month, so to stave off insanity I'm planning to blog from the ship to keeping you up to date with the latest discoveries. It seems to be a little known fact that members of the Bristol Biology department study deep sea fish and so I thought it best to bring a little of the research into the lime light.

Dr Nick Roberts, part of a team of Bristol vision scientists, has gathered together a group to investigate colour and light in nature. As part of this, a new post doc, Dr Juliette McGregor, will be looking at the effect of pressure on photoreceptors. The pressure exerted on deep sea fish is enough to alter the protein structure and this includes that of visual pigments so in August, Juliette and I will be collecting deep sea fish retinal tissue which will be used to examine their spectral properties under pressure (whilst trying not to be sick onto the specimens as we dissect stinky fish...on a rolling boat...in the dark).

Another ongoing project has been looking at the eyes of Malacosteus niger (image below) the stoplight loosejaw, a fish with red eyes, gaping mouth and a light organ underneath each eye that emits red light.

Stoplight loosejaw, Malacosteus niger

Most deep sea animals can only detect blue light (a colour common at depth as many animals produce blue bioluminescence) so by producing red light, M.niger can hunt prey or communicate with other individuals without fear of detection! Now what is particularly amazing about these creatures is what's found in their red eyes. In order to detect longwave red light, they use chlorophyll as a photosensitiser. But that's in plants I hear you shriek! Well, even stranger than that, the visual properties of the pigment is very similar to that found in small crustaceans it eats (see paper). So does M.niger use chlorophyll it obtains from its diet to alter the wavelength of light it can see?! We don't have the full story yet so watch this space...

Dolichopteryx longipes photographed from above

Another amazing discovery was made during a past research cruise by Professor Jochen Wagner (University of Tubingen), Prof. Ron Douglas (City University London) and Prof. Julian Patridge from Bristol. Whilst midwater trawling they discovered a live specimen of Dolichopteryx longipes (image right). Previously only one preserved fish was available for studying this unique species, the only vertebrate found to form images using a mirror instead of a lens which reflects light onto a second retina.

These fish appear to have four eyes and although there are just two, each is separated into two parts, one looking upwards and the other down. This allows D.longipes to detect silhouettes of animals above it, but also detect bioluminescence produced by animals below. For more info on this fascinating fish see this news article or paper.

I think that's quite enough biology for now, but I hope I leave you with a better idea of what strange things are going on in the Bristol University biological department and keep your eyes peeled for posts in August from the Porcupine Abyssal Plain, eek!