Seahorses

Alex Re

Hello, welcome to on wildlife. I'm your host, Alex Re. On this podcast, we bring the wild to you, we take you on a journey into the life of a different animal every week. And I guarantee you, you're going to come out of here knowing more about your favorite animal than you did before. On this episode, we're heading underwater to talk about some of the most unique animals on the planet. And luckily, we have Dr. David porosity, who is a senior research scientist at the Port Stephens fisheries Institute to help answer some questions about these amazing creatures. Some of their characteristics make it seem like they're not even from this planet. And I'm really excited to explore those characteristics with you. So make sure you put on your scuba gear, because we're heading into the sea to talk about seahorses.

There are over 40 different species of sea horses, and they're distributed throughout the world's oceans. And they usually live in more shallow waters where it's not too cold. They're relatively small animals, but the largest species is called the big bellied seahorse, and they can actually get to be over one foot long. But some species are extremely small, such as satomi is pygmy seahorse, which can only get to be around 14 millimeters long. Now, I don't know about you, but to me, see horses look ancient. And the earliest seahorse fossil was dated back to around 13 million years old, which is relatively recent when you think about other types of marine organisms. And I know you probably have 1000 questions about seahorses, like what type of animal they actually are, and do the males really give birth? Well, David is going to give us all of that cool information and more. He's been working with marine species for over 20 years and has a vested interest in sea horses. He even did his PhD research on an endangered seahorse species called White Sea Horse. So let's take a quick break. And when we get back, you're going to hear my interview with David.

The person that I want to recognize in this week's episode of notable figures in science is Dr. Beck Strauss, who is currently a planetary geophysicist. They got their PhD in Earth Science from the University of Minnesota, and they're currently researching why moon rocks have a magnetic field. They're also working on a way to calibrate certain instruments that geophysicists use in the field when studying magnetism. Not only that, but they're also the president and founder of a queer Employee Resource Group at ni St. They're still young, but they're paving the way for anyone who wants to work in the scientific community. If you want to learn more about Dr. Strauss or this series in general, check out on wildlife.org.

Okay, we're back. Here's my interview with Dr. David Harasti. Hi, David, how are you doing?

David Harasti

Great. Good to have you on board. Thanks, Alex.

Alex Re

Thanks so much for coming on. I really can't wait to get talking about sea horses. But first, can you just tell us a little bit about yourself and how you became interested in sea horses?

David Harasti

altogether, a long, roundabout story how I got involved in safe houses. I went to university to save kangaroos and koalas and I wanted to look after the warm and fuzzy animals. And halfway through my degree, I took up scuba diving, and I fell in love with the marine environment. So I completely changed degree halfway through uni I swapped In I started a Marine Science went towards the marine science courses. And I first saw my first seahorse in 1997. And I was just captivated by this mythical animal in the ocean. And my love of diving and underwater photographer led me down the road of becoming a seahorse scientist because I was so captivated by him. That's awesome. And it must be so amazing to actually get to see a seahorse in in the wild. It's a highlight for anyone that sees one I take my young kids snorkeling, and you know, if they find a seahorse in the seagrass, they are just saw excited. And if I'm down there, and I find a seahorse and his other kids around, I'll show them and they just can't get over this amazing looking creatures. This mythical animal that's coming out of the ocean and everyone's just captivated by him. I don't think I've ever come across anyone that said they don't like a seahorse or mean either.

Alex Re

And they really don't look like anything else in the ocean. And we're gonna get to talking about that a little bit later. So I can't wait to hear about that. But you are also a researcher at the Port Stephens fisheries Institute. Can you talk about some of the research that you've conducted there?

David Harasti

Yeah, so I work as a marine scientists for fisheries in New South Wales. And I'm quite fortunate I've got a really diverse job. So, one day I might be working on great white sharks and doing baited video surveys for them off some of the beaches here. The next day, I might be doing seahorse surveys in the porcelain industry. I've worked on turtles. I've worked on Greiner shots, great white sharks. There's a threatened fish over here called the Black Cod. So there's a lot of hours spent in the water diving and seeing the marine environment. And it's, you know, it's a real highlight of my job and I get to go diving, it's not always great. Sometimes we do diving in really, really poor visibility and award is really called so it's, it's not all tropical, rave Blue Water really warm swimming around in boardshorts. Sometimes during your dry so it's cold and you're miserable. And you don't want to be there. It's not always the best.

Alex Re

I can imagine. Yeah, they don't show you all that. The nitty gritty side of the research often.

David Harasti

Most definitely not. And to be honest, probably at this time I'm spending at my computer in my office doing work and training for seven time I'm out in the field. And that's 20% of the time out the field is what you know, makes me love my job.

Alex Re

Yeah, absolutely. And the 80% is also very important for your job, too. So

David Harasti

Oh, most definitely, like when we do all our research work. We've got to write up our research so we can share it to the wider community so I can understand what's happening in the ocean.

Alex Re

Yeah, absolutely. So let's just start talking about seahorses. So they, like I was saying before, they don't look like any other organisms living in the ocean. So what exactly is a seahorse? And what other animals are they closely related to?

David Harasti

Well, that's the thing about the seagulls. Not not they don't really look much like anything else. And the reason for that the scientific name for the seahorse agenesis hippocampus. And in ancient Greek, the word Hippo means horse, and campus means sea monster. So they are the horse sea monster, they have the head of the horse and the body of the sea monster. And they're very bony and rigid animal, they're quite tough. And the most obvious thing about them is their head inside a 90 degree angle to their body. And they've got this really long title. And that title is really important because I need that tile, to curl around and hold on to habitats. And closely related to them in their same family is known as the signified a family. There's pipe horses, there's pipe fish, which is a long, skinny fish that live on a sea floor. And also sea dragons. There's three types of sea dragons, which are all endemic to Australia. And they're closely related to the sea horses as well.

Alex Re

sea horses have a lot of features that make them stand out, including eyes on the side of their head. David, let me know why this helps them in the wild.

David Harasti

See, horses are quite special in that their eyes can move independently of one another. So left, I can move in one direction, the right move and the other. And the reason for that is that they've got a hunt for they're really small microscopic foods. So they can move their eye on one place looking over here and and I'll keep their eye over there to find what they can eat. So just like a chameleon can move its eyes independently or the mantis shrimp underwater. The seahorses have the ability to do the same thing. And it's purely so they can keep their eye out for the prey that they're looking for. I'm probably and probably to avoid predators as well.

Alex Re

Yeah, absolutely. That's really cool. And probably a very useful thing when you're floating around in the ocean. So I also recently learned that seahorses don't have teeth and you were talking about looking for their prey. So So how do they eat and what special feeding adaptations Do they have that helps them do this?

David Harasti

Right. So you're right, the seahorses don't have any teeth. And what they have is I have this long snout, and at the end, that's now if they have a little mouth. Now I refer to the seahorse is when they're fitting is basically underwater vacuums. So they'll find a little microscopic shrimps and these shrimps, little cocoa pods or amphipods. There's too small for us to see as humans, but you put them under a microscope and you can see what they are. So when a seahorse finds one of their their prey, they'll flick their head, and then there's this little quick action in the mouth and sucks up the prey. And because the seahorse doesn't have any teeth, they swallow the prey house or this, this shrimp goes into sales body Hall. And they don't actually have a stomach to see horses has a really long digestive tract. So they're constantly eating and pooping by all the time so they have to eat all the time for energy because they're expelling their food so quickly. They have to keep eating otherwise they won't have enough energy to survive. They are feeding machines, underwater vacuums, basically they're just constantly eating.

Alex Re

That's really amazing. I've never heard of not having an actual like stomach before. That's That's crazy.

David Harasti

Yeah. And that's and that's why they you know, the food passes through them so quickly. And can you imagine like if we're eating all day, and we're not storing any of that. We weren't having any You would just be lying around. And that's the same as the seahorse. So that's why they've constantly got to be fading. And if you're ever watching a seahorse in an aquarium, every now and then you'll just see them flick their head. Now you can see what they what they're trying to eat. But that's actually when they're eating is I'll flick their head, they'll vacuum up their prey, and we can't see the prey, but that's what they're doing. Wow,

Alex Re

that's so cool. Another unique feature of seahorses is that they don't have huge fins like a lot of fish do. I wanted to know how they get around.

David Harasti

Okay, we can put it this really easily. seahorses are not designed for speed. They are one of the slowest moving fish in the ocean. And the reason for that is that they have this tiny dorsal fin on their back. And I fluttered madly to propel themselves forward, and they stay with a little pectoral fins on their head. Now, they're not fast, they can't out swimmer predator, they, you know, the smallest seahorse adores seahorse moves on average, like one and a half meters speed over over an hour, so not fast at all. So what they must rely on to survival is camouflage. They can't outrun their predators, so they must try and blend into their surroundings. So seahorses are actually quite tricky to find in the wild, because they can change their color to match what they're living on. So you can often find a gold seahorse living in a gold sponge or a grainy gray colored one in the seagrass. And they'll change their color to adapt to what they're on so that the predators can't see them. And camouflage is one of the most important things for their survival.

Alex Re

That's insane. And I never even knew that seahorses could change their color. That's something that you think about, like with, you know, like a chameleon, or maybe an octopus but not not a seahorse. Yeah, and I

David Harasti

do it gradually over time. So we tag our seahorses, here with little colored injections known as using elastomer, so I can follow the same animals and you know, might have a seahorse it's black living the seagrass. And three days later, you'll see him living on a gold sponge. And you can see him gradually changing their color over a couple of days to match the sponge that they're living on.

Alex Re

It's really cool that that is really cool. And I guess that the seahorse name is kind of deceiving because you think of a horse running really fast. But see horses not not so fast. Yes, he

David Harasti

also is definitely not fast. There's no speed in this horse, that's for sure. Like when we do our work on people often ask like, how do you catch them on like, what's not hard, I just grabbed them with my fingers. And because I don't go anywhere, very easy to catch a seahorse.

Alex Re

And you were talking about their predators, too. So what kind of predators do they have in the wild?

David Harasti

Yes, that's an interesting thing. So some of the research I've done here over the years has looked at what age predators so there's several types of fish we found that ate them so big Flathead, like to eat them. Our Scorpion type fishes, the fish that live on the bottom, they're spiny. They're ferocious predators of the seahorse, like the Red Rock Cod, for example. But then there's other animals. So the octopus is a massive predators, seahorses and I've had some encounters with octopus trying to attack the seahorses. I've been researching and, you know, I've had to interfere of nature says stop the octopus at my four little seahorses, which I know you shouldn't do. But you know, I'm not wanting to let my signals to get eaten by an octopus, and other things like cuttlefish as well cut official or prey on the seahorses. The interesting thing is I just seahorses are quite bony. They're quite hard. So a lot of the time like an octopus might attack and it might kill a seahorse but it doesn't eat the whole body because it finds it quite bony. So I've often found on the floor near and octopuses den like the remains of one of my stables is dead and it's it's kind of really sad to say that that's happened like laces like lace of the octopus had a proper full male and lace. I know that's been used properly. But it's defined three quarters of my seahorse left I'm like, Oh, that's really disturbing.

Alex Re

That is kind of disturbing. So even though there are a lot of things that eat it, they're not they're probably not the most nutritious meal that that a predator can have.

David Harasti

No, definitely not. And like when we cut open some large fish like dolphin fish and snapper inside the fish is you can often find like whole seahorses just laying the digesting in the fish's stomach and especially some of the pelagic species can often you know, we had a dolphin fish cut open and it was about 30 seahorses all completely holes sitting inside. And they just you know they break down so they're providing nutrition to to to the fish but it's kind of sad, really like we don't want to see horses being eaten. Like what have I ever done to harm anyone?

Alex Re

Yeah, exactly. And especially not being eaten alive. That's That's even worse, I think.

David Harasti

Yeah, no suffering. No, I don't like thinking about what I used to say horses, the poor little things.

Alex Re

Yeah. And I think we've all heard the fact that see horses are one of the few species where the male actually gets pregnant. Can you explain this process a little bit and how it differs from other animals.

David Harasti

Yeah, and this is what makes the horses really cool. It's one of the only animals in the world where a mile will give birth. And the mile can be identified by the pouch that has on the front of its body. And what happens over the breeding season, a male and a female will come together and they do this beautiful morning ritual mating dance. So they'll wrap their towels together, and I'll raise up into the water column. And if that male isn't pregnant, the female will transfer her eggs into his pouch. And he'll fertilize them inside the pouch. And he might be pregnant for anywhere between depending on space anywhere from 10 to 40 days. Now, the spaces I work on here in Australia, the white seahorse, that's 20 to 21 days, you can set your watch by it always happens on about 21 days. Now, when the mouse gives birth, he might pop out anywhere between 50 to 250 babies at a time. And all these little babies, seahorses will pop out and they're fully developed. So they look like a seahorse except they're very, very small. The size of the white seahorse babies are only eight millimeters. So just under a centimeter long, which is about half an inch. And as soon as he pops them out, there's no parental care. They're on their own. And there's this big wide world. And unfortunately, during the birthing process, all these babies will be popping out. And that's a really good opportunity for the predators to come in. And predators will actually fade on these babies seahorses. So the survival rate of baby seahorses isn't very high. It's probably only about say 5%, maybe, maybe less, maybe around one. Otherwise, you know, can you imagine all these babies being born in the whole ocean and be overrun by seahorses, which would be fantastic. It's just that they're not growing up to survive. And then once that man was given birth, a few hours later, the female will come in approach him again. And you know, the poor see or smell, see or just want to rest after three hour, four hours of labor. But she'll impregnate him again, she'll stick some more eggs back into his pouch, and the whole cycle started all over again. And over breeding season, a milesi hoskin goes through this process at least eight times. Wow. Yeah. And you imagine so he's popped out, you know, the white seals might pop out 100 150 bags at a time. So he's given birth to over 1000 animals during a breeding season. So by the end of that breeding season, he just needs a rest. Yeah, I

Alex Re

would assume. So. That's, that's pretty amazing.

Unknown Speaker

Yeah, and one of the other really cool things we found here in Australia, the research that I was doing is that they can despite long term monogamy, whereas they sort of fall in love with each other. So they'll partner up to the breeding season, if both of them still are still alive The following year, the same animals will breed again together. And I've had to two pairs breeding for three breeding seasons in a row. And they don't move very far, they might only be one or two meters away from each other during their entire life cycle. So it's pretty fascinating. They fall in love, they find a little happy place and they stay there. And if none of them get eaten, or they die from old age, they'll stay together. So they're really loyal to one another, which is such a beautiful story in the Marine world, I think.

Alex Re

Yeah, absolutely. I feel like more people should know about this, the seahorse loves story. And it's a remarkable thing. And I imagine the the reason why they have so many babies at a time is because of that low survival rate.

Unknown Speaker

Exactly. So, you know, otherwise, like I said, Imagine, hundreds say horses living here in an s3, they pop out around 1000 babies ever brings in so you could have 100,000, say horses taking over yesterday, but you never see that many. And that's because the survival rate is so low. And that's why they actually have to keep reading and keep popping out more to get the survival up.

Alex Re

Yeah. And you were talking a little bit about their reproduction and their populations. So what are some of the challenges that seahorses are facing right now?

Unknown Speaker

Right, and that's a great question. It's one of the sad things about the seahorses. So, all around the world, seahorses are under threat. So populations are declining. And that's attributed to three things. The first one is overfishing. The second is being caught as bycatch. And the third is habitat loss. Now with the overfishing in places such as India, Vietnam and Thailand, up to over 30 million seahorses can be collected each year. Wow. And then traditionally use for they're basically used for traditional Chinese medicine. So seahorses using traditional medicines for curing illnesses such as respiratory disease and other ailments. So there's a demand for the seahorses. So unfortunately, because there's a demand there's people that go out and I'll fish for him and catch him. Now fortunately see horses listed on site he's which is convention for Trade in Endangered species. And those countries that signed up societies they regulate the trading and seahorses. But there's still a lot of illegal and unreported illegal fishing that occurs, and hence the seahorses. As quite often you'll have seizures of lots of dried seahorses destined for the illegal market. And then the second one is the bycatch. So when we eat shrimp or prawns as we call them, Australia, the shrimp fisheries will troll over the sea floor. And when they're trolling for their prawns and shrimp, they'll bring up seahorses by mistake. And so those seahorses taken us by cash. And then I'll also be, you know, sold sold in fisheries markets. But the problem with the trolling is that bottom troll is, trolling is really indiscriminate. It doesn't actually select what fish they're going to take, they just take everything on the sea floor, and not just the fish, they actually will also roll over to seahorses habitats, and they'll destroy the habitat as well. So those beautiful fans and sponges, the seahorses might live on, they'll get trolled up, which leads on to the third one, which is habitat loss. So all around the world, seahorses habitats such as the sea grasses in the mangroves, and the sponges and soft coral gardens. They're all declining quite rapidly in some places. And, you know, if we don't have this, the habitats we won't have to see horses, to see horses rely on marine habitats to live in, because that provides food for him. It provides camouflage for him. And they use a nice long tails to grip onto a habitat to hold them in place. And most of them are very territorial, they'll stay in that habitat for a long time. So if that habitat is lost, the seahorse doesn't have anywhere to hide and survive.

Alex Re

Yeah, so they're obviously facing a lot of problems. And a lot of them are due to us. Most of them are due to us.

Unknown Speaker

Yeah, like yet, unfortunately, as humans are having major impacts on marine environments, so many different ways. And some of the activities that we're doing is actually causing great harm to sea host populations. And that's why on the IUCN Red List, we have quite a few seahorse species that are listed as endangered, they're listed as vulnerable, which means if we don't put actions in place to reduce the declines, those species could become extinct in the future. Yeah, definitely.

Alex Re

And what are some things that we can do to help?

David Harasti

Oh, that's a great question. There's so much we can do to look out for our marine environment. There's so many initiatives out there. Most importantly, is if you're ever traveling, and you see to drive see horses for sale on a keyring or in a pipe waiting, don't buy them. There's if you buy the seahorses the dried seahorses, you're actually creating a demand for them, which means that they're going to increase supply, they're going to try and get more so never ever buy dried or dead sea horses. And then on your local level, strive to support your local conservation issues that are looking after marine environment. We have activities here in Australia where citizen science projects where you can go out and you can help replant seagrass you can help do seahorse through project seahorse you can do seahorse photography and submit your photos into icy horse and project seahorse to get an understanding of where to see horses are found. And then we learn more about them. And we might learn to see horses in areas where we didn't know which would be great. And then there's other things that we can do where habitat has been lost, and it's not coming back, there's initiatives in place to try and replace that habitat. So a couple of years ago, I came up with the idea of seahorse hotels, and a seahorse hotels are these artificial habitats we put back into the ocean places like Sydney Harbour, to provide habitat for the endangered white sea horse to live on. And they've been really, really successful. And now in Australia, we have this great initiative under Taylor's wise, it's called the sea bnb initiative. And you can look that up on our website cdbaby.com.au. And under that initiative, we're raising money to put artificial habitats back in the ocean for the endangered white seagull, so it doesn't decline in the future.

Alex Re

That's really amazing. And I would love to check that out. Everybody should get definitely go to that website. And check. Check that out. And you were talking about some of the things that we can do. And it's really easy to not buy something, right. And it's also it could be really fun to do some of those initiatives where you're helping to replant sea grasses and take photos of sea horses. So conservation can be easy and also fun.

David Harasti

almost definitely, as I say to all the people I meet, and in my travels around the place, go snorkeling. Go into the marine environment, take your kids snorkeling, go and see what's out there. And then when you do you're such appreciate what we have in the ocean, you know, swimming over seagrass field and there's you know, beautiful fish swimming over it and there might be cuttlefish and if you're lucky enough and you find a seahorse that's going to make your diet or make your week and sort of gives you that sort of pride about the marine environment. It gives you a bit of stewardship over so Those people that say that then I appreciate what they can do to try and help maintain and restore it in those areas where it's needed.

Alex Re

Definitely. And it's it's one thing to look at a coral reef or or a seahorse on a screen. But it's another thing to actually go out and and see one for yourself in the wild. It's just, it's a completely different experience. And it's amazing.

David Harasti

Oh, most definitely. Some of the biggest smiles I've ever seen from children are the ones that have taken snorkeling or shown in a seahorse. They've touched the seahorse. They've seen a seahorse. And they'll go home now tell their parents about that forever.

Alex Re

That's so cool. And David, thank you so much for coming on. today. I really appreciate you sharing your knowledge with us. And I really learned so much about seahorses.

David Harasti

No worries, Alex. Thanks for having me on board that was so much fun.

Alex Re

David really gave us some amazing insights about the incredible lives of seahorses. They're so different from any other animal. Unfortunately, like David told us see horse populations are struggling right now. That's why it's so important to support organizations that are helping them. You should absolutely go take a look at Port Stephens fisheries Institute. Some other organizations that you should check out our project sea horse and the sea horse trust. Thank you so much for coming on this adventure with me as we explored the world of sea horses. You can find the sources that we use for this podcast and organizations that we reference at on wildlife.org. You can also email us with any questions at on wildlife. dot podcast@gmail.com and you can follow us on Instagram at en underscore wildlife and on tik tok at on wildlife. Don't forget to tune in next Wednesday for another awesome episode. And that's on wildlife.

Jess Avellino

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