Most of what we know about neuroscience has been worked out from research on animals in the sea. One of those is vision. Professor Justin Marshall talks about how important sea creatures are to our understanding of neuroscience, particularly vision. And Dr Fanny De Busserolles tells us what we can learn about vision from the creatures that inhabit the deep, dark depths of the oceans.

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Donna: Growing up, many of us are told by frustrated parents to eat our carrots to see better in the dark. Though carrots contain Vitamin A, which is essential for eye health, they clearly don't give us night vision. But could we see better in the dark? Could we avoid things that go bump in the night, namely shins into furniture. QBI's Visual Ecology Lab might have the answer and it all seems a bit fishy…

So, I’m here with Professor Justin Marshall, who studies marine life and visual ecology and we're standing at Queensland Brain Institute’s workshop in front of some giant steel beams that being welded together. Justin, what are we looking at here?

Justin: Donna, this is very exciting for us because we are putting together a new net system for deep-sea trawling. So, we're doing what people do to go and catch fish to eat, except we're going to catch fish much deeper – maybe down to 3000 metres – and look at them for their sensory systems. We're fascinated by how animals in the deep sea  – where sometimes there's no light – how they live and why do they have eyes?

Donna: So, in terms of this deep-sea creatures, they look very weird and wonderful because there is no light down there. So, how do they see and sense things?

Justin: That's a good question, and you know, you pull up a fish from let's say 2000 meters and we know from measurements that light from the sun doesn't go down below a thousand meters. So, these fish apparently are in complete darkness, but the answer there is that they use bioluminescence. So, they are producing their own light and communicating in order to find things to eat and to find mates to mate with, and to avoid being eaten. So, they use Bioluminescence as a distractor. So, they use it to distract possible predators. So, they're conducting their lives in complete darkness.

The second part of the answer to the question is that some animals live in that top... let's say 200 to a 1000 meters where light is dwindling, so you're in a sort of what's called ‘missile pelagic realm’ and there this deep blue light. Again, life there is very different and we’re very interested in how these animals are conducting their life in that dim light environment.

Donna: So, what do these sea creatures have to do with neuroscience?

Justin: In fact, most of what we know about neuroscience was first worked out on animals from the sea. Almost everything that we know about the basics of nervous conduction and how a nerve works and how it conducts information from A to B was first discovered looking at a squid. This was Hodgkin and Huxley in the Plymouth Marine Lab. in the United Kingdom and they used squid because they knew that they have very big neurons and they wanted to work out what the chemical processes were. Since then, the sea slug, the aplysia has been used as a great model to work out how synapses work; crabs have also been used. So, in fact, studying animals from the sea has enormously contributed to neuroscience. A lot of what we know about, nerves and brains and sensory systems has come from the study of these animals and we’re continuing that tradition in finding out some really fascinating things about their sensory existence.

Donna: Your works specifically looks at vision in these animals. Can you talk a little bit about that?

Justin: My group at the Queensland Brain Institute, we’re fascinated by how other animals see the world. And as arrogant humans, we tend to assume that the world is the way that we see it and that’s absolutely not the case. There were very good examples of animals that have much better color vision than we do. Now, birds have much better color vision. Some of the fish in the ocean have much better color vision. Some of them don’t have color vision at all and if you’re living in the deep sea where light is either very blue because that’s all that’s left from the surface or it’s very blue because that’s the bioluminescence, the light that’s produced by other animals is blue, then there’s not much point in having very good color vision. There’s no point in seeing red because there’s no red light there. However, if you’re one fish, Malacosteus niger – their common name is a trap jaw sort of dragon fish because they have very big teeth – and these fish use red light. So, they actually have a bioluminescent organ, essentially a head lamp which is red because they know that the other animals down there don’t see red. They’re the only deep-sea fish that we know that does see red. Essentially, these fish have pre-invented what we know is infrared vision. So, cameras that can see in the infrared, we can go around a potentially snipers or something; if we want to see people in the dark and we don’t want them to see us we use infrared. These deep-sea fish, the Malacosteus use red light and they pre-invented this system of snooping around trying to find things to eat millions of years before we did.

Donna: In the twilight zone of the deep sea, one of the dimmest habitats in the world, Lantern fish ironically use light to hide themselves. What visual adaptations they use? And, how does this even relate to us? QBI's Dr. Fanny De Busserolles, explains:

Dr. Fanny: Yeah. So, it’s very interesting area of the ocean for two (2) reasons; so, they steal a little bit of light from the surface switching these depths. So, between 200 and a 1000 meters you can still have light from the sun, the moon, the stars the can reach these depths. So, obviously we can’t as humans, see that but the habitant of these zone have eyes where they are sensitive and can see what level of light; And, in addition to that you have bioluminescence, which is a light, but is produced and emitted by the animals living in this zone themselves and you have a lot of that in this area. So, even though it’s a very dim habitat they still some and a lot of light signals going around for animal to use and communicate and yeah so, it’s really interesting. A lot of variation in this area compared to the surface or the very, very deep which is way even darker or you will only have the bioluminescence

Donna: So, bio-luminescence is kind of adaptation that this fish have developed. Can you give some examples of what these creatures look like or use the light for?

Dr. Fanny: Yeah! So, they use the light for a lot of different purpose. Many of them use it to communicate, either to attract a prey – for example the anglerfish, the scary one in Nemo with a line dangling in front of him is actually a lure to attract prey, and so we use it in this fashion. They kind of so use it to avoid the predator, so they will flash a little bit of light and the predator who sees the light would be attracted by it, but this time it’s a fish. And the animal has time to escape, so it’s a distraction. Communication specific lights in all to attract a mate or talk with another individual; and also, to camouflage themselves. So, a lot of fish like the lantern fish for example they have a lot of luminous organ on their belly. So, the entire surface of the belly is covered with tiny luminous organs that emit light and they match the illumination of the background light and so they can disappear for a predator that is looking from below. So, they are counter shading their bellies to disappear in the ocean.

Donna: It is almost ironic that they actually using light to hide themselves

Dr. Fanny: Yes.

Donna: Can you tell me a little bit more about the lantern fish? 

Dr. Fanny: So, as the lantern fish really cool family of deep sea fish. They are one of the most abundant family of fish in the ocean. There are more than 250 species of lantern fish in the world. They are really tiny fishes, but very interesting for my kind of studies because we are very, very diverse in terms of behavior, distribution, the pattern of venomous organ they have on the body, how they use this to communicate; a very varied family of fish. And they are really, really important in the ecosystem because they are performing vertical migration. So, during the day they live very deep, so in average of 500-1000 meters and then at night they are going migrate, swim all the way back to the surface, some really right at the surface of the ocean to eat. So, every day you have these migrations of fish that is going up and down to eat and then camouflage in the dark.

Donna: Wow! So, it’s like a defense mechanism to hide down below and then come up for food?

Dr. Fanny: Yeah, exactly.

Donna: So, what do we hope to learn about vision by studying fish like the lantern fish family?

Dr. Fanny: So, fish are quite interesting for adaptation studies because they are very plastic. They are adapted to live in so many different environments, like when you think about it there are fish living in a coral reef, in the lake, in the river, in the deep sea and so we can really like see how they adapted to a specific environment and vision is one of the main sense that they use by most animal to perform daily task; And, although it’s very dark in the deep sea they still have a quite visual environment and lantern fish use predominantly vision to perform their daily task. So, by studying this fish and how their eye and is adapted to see this very, very dim light conditions and very specific seen all, we can learn a lot about how the visual system evolved? How this fish survived in this environment? And, we can learn a lot of so bad behavior because not much is known and we cannot really study them in the deep because it’s very hard to access and we can’t keep them alive in aquarium either. We don’t know yet how to do that. So, the only way to have a bit of a glimpse of what we can do or how we behave is to study their sensory system and how they perceive their environment and how they react to it. 

Donna: So, in terms of studying these animals you mentioned that it’s quite difficult. How do you study them?

Dr. Fanny: So, we go on big research vessels usually for a few weeks at a time and we trawl the fish, so we would put a big net in a water and we will target usually a specific depth often we do that at night because most of the fish have migrated to water surface to eat, so it’s less deep we put the net in the water and when we bring bags off net onboard after a few hours of fishing and then it’s a bit like Christmas you don’t know what you’re getting so it’s less deep. We put the net in the water and when we bring back the net on board after few hours of fishing and it’s a bit like Christmas, you don’t know what you’re getting. So, it’s a very exciting moment with the scientist on board. We just look at the bucket of fish and say ok what do we have? Do we have a new species? Do we have the species we were looking for? And, that’s what is tricky because you never know what you are going to get. So, even though you have in mind a fish you really want to study you, never know if you’re going to get it.

Donna: In terms of studying vision what can studying the visual systems in these marine animals tell us about either humans or about visual in general?

Dr. Fanny: About humans, probably not so much directly because we have a very well-studied visual system and we know what we see and often we have a bit of biased by that because we have a tendency of thinking that what we see is what other animals see. So, by studying deep sea fish, we try to get a bit out of our own perception and try to picture how those fish – so what is their environment and how they can perceive things. So, example most deep sea fish we don’t have a very acute visual system. So, they don’t see shapes, very defined shapes like we see, but they have a very very sensitive eye, so they can detect the tiniest amount of light that would be in their surroundings, more than us, very quickly, whereas with us, it would be completely dark and I don’t see anything. So, it’s their differences, and the certain type of adaptation that we find in fish later on can be applied to robotics, like to improve our own dim line vision in the army, in [that] there can be a lot of application depending on what we find also.

Donna: So, its potentially to help us see better in the dark?

Dr. Fanny: Could be yeah, definitely.

Donna:  What’s your favorite fact or tidbit that you’ve learned in the course of your research?

Dr. Fanny: I think from these my favorite fact is the interaction that the deep-sea fish have between one another with the bioluminescence, I think is very fascinating and then you have some weird animal facts like some species will be able to eat an animal that is bigger than themselves. The anglerfish male that is tiny and just going to be a little parasite on the female and fuse with the female body and just become a sack of sperm for the female and the female can have a lot of different males attached to her.

Donna: That sounds terrible for the male. [Laughing]

Dr. Fanny: Yeah, it’s not very nice for the male that's for sure, but its yeah the deep sea is fascinating because it’s such an extreme environment this it’s very vast, so big, its dark, cold, lot of pressure and then the deeper you go, it’s a less a biomass you have, the less animal you can see; and the species they had to adapted to like think; “Oh! I might not find my next meal tomorrow I might not eat for two weeks because I might not see a prey in on that amount of time or I might need to find a mate as soon as I see something. I might just keep it for myself because I might not encounter another mate for a very long time.” And, so we have developed this crazy adaptation to survive in this condition and I think that's really, really cool.

Donna: That was Dr. Fanny De Busserolles, discussing lantern fish and the deep sea. Now, back to Professor Justin Marshall, to find out more about his research and upcoming trip.

Justin: We’re very lucky in that we are working with a German ship, the [RV] Sonne which operates in the Pacific and we’re collaborating with German colleagues from the University of Tuebingen. So, Professor Hans-Joachim Wagner is the chief scientist in this expedition. We’re also working with scientist from the University of Western Australia and from England, from London Universities. So, it’s an International team that’s come together and we’re setting sail, although there’s no sails involved, but we’re setting out from WA going across the Indian Ocean to Sri Lanka, sampling animals, having look at how they live along the way and also putting down two different sorts of deep-sea camera, to film the animals doing their natural thing, in their natural habitat, as we go.

Donna: I saw a cool piece of tech that you had upstairs. It’s a camera that attaches to the iPad and by steadily walking around an object you can capture. It’s in complete 3D with all its complexity. What will you use this camera for?

Justin: Ah yes, it’s a new thing. So, it’s a scanner. It’s a… lots of people have them these days, so it’s a sort of thing that you can just clip to your iPad, scan an object as you sail all the way around. You either walk around it or you put in turntable and we’re gonna use this to recreate some of the deep-sea fish. You can then plug the data into a 3D scanner and make the fish. And, the sorts of thing we’re going to be doing are making fish, making cephalopods, octopus, squid, cuttlefish, in order to model what potential mates might seem when they see each other. So, we’ll be using this tech to try and recreate deep sea life because it’s very difficult to actually get down there yourself. I mean, I’ve been lucky enough to work with submersibles. I’ve been to the deep sea, but you’re only there for a couple of hours at the most. So, we have to recreate what they’re using this sort of technology.

Donna: Justin, you've been on some really exciting expeditions. What would you say is the most interesting or fascinating research you've been involved in?

Justin: That's a really difficult question. I've been very lucky, you know, and I've done lots of things in lots of cool places. I got to work on the Great Barrier Reef. I got to be the tour guide for Sir David Attenborough going around the Great Barrier Reef  and part of that was to go into the deep waters of the Great Barrier Reef in a submersible with Sir David and that was just amazing. So, that was – in terms of getting the research out there – that was certainly the pinnacle of my career because I was working with the world’s best science communicator in the environment which he loved and I loved and it was amazing. I've also been lucky enough to be on a number of scientific expeditions on new submersibles and go to the bottom of the ocean and look at and capture animals that lived there. So, my research takes me from deep ocean all the way up to the very shallow reef systems and looking at how animals in these different environments adapt. So, if you had to pin a label on me, I'm a visual ecologist, so I work on how visual systems respond to the ecology and to the physics of the environments in which they live

Donna: You're and avid supporter of reef conservation and you lead a group called CoralWatch. In recent years, there's been a lot of damage on the Great Barrier Reef which is more than a little bit concerning and what can people at home listening do to help protect the reef and what are ways?

Justin: That's a very important question and certainly part of what although this expedition we’re going on is about the deep sea. We’re working on connectivity issues and how the surface connects to the deep and part of the surface as you say, Donna, is the reef systems in the great barrier reef and the new date of its coming out from a number of groups including coral watch but mostly led by Terry Hughes and the center for excellence for coral reef studies in Townsville is that we’ve lost in the north up to 70 per cent of our reef systems. That’s an area the size Scotland that we’ve lost in the last two years, so it’s devastating for the scientists, it’s devastating for Australia and it’s devastating for the world. At CoralWatch, what we’re trying to do is unconfuse people, if you like. A number of people, many people, are still confused by what they hear in the news, what a set of misguided politicians are trying to suggest that we haven’t that we don’t have and that we should and should not do. So, what we do is provide the opportunity to go to the reef, to monitor the reef; and help gather data if you want to but increasingly were providing educational tools for school and opportunities for people to recognize what we need to do and what we need to do most definitely is run at renewable energy as fast as possible. So, global climate change is causing these problems in the same ways as global climate change is causing the melting of glaciers in the North Pole, which is driving polar bears towards extinction as we speak. The Great Barrier Reef has suffered these two massive bleaching events in a row 2016-2017 and before that in 1998 and 2002 and these events are absolutely unequivocally linked to climate change. There's essentially no such thing anymore as a climate change denialist because you might as well deny that the earth is spherical and think that it’s flat, so most countries have moved beyond their pushing as hard as possible towards renewable energy and that’s the thing that we must do in Australia. At this point, many people throw their hands in the air and say oh the government must do that and it’s going to cost me too much to do anything or little me I can’t do anything. You absolutely can! Anything you can do is going to help. So, even switching your lights off at night time, turning your television off, turning your computer off completely at nighttime that's gonna help and then changing lifestyle more and more. I mean you don't have to be a completely invisible hippie living in the woods, having a zero-carbon footprint and floating about the forest in a sort of sane existence. Anything you can do at home is going to help in terms of sustainable living, possibly one of the most important things we can do is source our energy from renewable sources. In this way, essentially pushing the carbon-based energy sources out of business.

Donna: Is there anything else you'd like to add about the expedition?

Justin: I think only that it’s a great privilege and its fantastic opportunity so I’d like to thank the German vessel the [RV] Sonne for taking us out because essentially their paying for most of these they to run a vessel that size is a hundred thousand dollars a day and they’re letting us use this partly because of our previous collaborative contact with a number of German scientist. So, as I mentioned in the beginning it’s a great international effort to understand the oceans to as well as gather scientific data, show everyone what these oceans are like, the fantastic life that lives there and we hope very much that when people see this they will be inspired to keep the ocean as it is and protect the ocean not exploit the oceans as we’re currently doing and essentially live as better animals on a shared planet.

Donna: That's all for this episode of A Grey Matter. If you'd like to find out more about Professor Justin Marshall’s work, please visit for more information or to find out how you can support coral watch. Visit I'm Donna Lu and our podcast is produced by Jessica McGaw. If you enjoyed this episode, let us know on social media. Tell your friends or give us your review on iTunes. Thanks for listening.

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