And I'm Madeline Walden and this is Aquarium of the Podcific. A podcast brought to you by Aquarium of the Podcific Southern California's largest aquarium.
Join us as we learned alongside the experts in animal care, conservation and more. Welcome back to Aquarium of the Podcific.
I'm Erin Lundy, conservation coordinator for mammals and birds and animal care specialist.
And I'm Madeline Walden, the aquariums digital content and community manager. Erin what are we talking about today?
Today we're learning all about sea stars.
You're a star
and you have tube feet
your very well so I mean, I'm very fast.
Are they fast?
Oh, sea stars are fast.
Really? How fast?
I mean, we're gonna get into it
Like 45 miles an hour. I like the idea of a sea stars running with all those millions of tube feet all over. I don't know anything about sea stars, other than they have tube feet. And the one time that I dissected one in college it was full of squiggles and that's all I know.
We're gonna learn more from Aquarist Jen today who we have on the podcast to talk to us about sea stars. And some conservation efforts that the aquarium is involved in with sunflower sea stars.
Jen is our resident star expert who does a lot of work actually raising sea stars from spawn again the same question of what we had last week jellies are they birthed? Are they spawn? I guess it's not a birth. It's very confusing. Thankfully, we have someone thankfully we have the experts on. So I know see stars are echinoderms. And they have radial symmetry. And that we do have sea stars. You can touch here at the Aquarium. That part I know. And some of them are really like leathery
Yeah. Some are bumpy. Some are very smooth You can touch our sea stars in our northern Pacific gallery at our coastal corner touch lab, and
your fingers will get cold.
Yeah, it is really cool.
But I think that's one of everyone's favorite exhibits. There's so many things in there, you can actually touch a sea urchin, and they'll give you a little hugs on your finger. It's my favorite. That's actually tube feet too!
to it is we're actually gonna talk a little bit about urchins with Jen. Because they're very closely related to sea stars
which you wouldn't expect by looking at him. Yeah, yeah. All right. Well, let's have Jen on. I'm looking forward to talking to her.
Today on the podcast, we have Aquarist Jen Burney. Hi, Jen. Hi, tell us about your job here at the Aquarium of the Pacific.
I am a senior aquarist. And I work in our cold water northern Pacific gallery. And I am in charge of all of our culturing. So that just means I am making fish and invertebrates that can either go on display or be part of conservation projects
making fish.
I love it. What a job.
Yeah. It's great. I feel all powerful.
So I know you work with a variety of animals at the aquarium. But today we're gonna focus on sea stars. Yeah. And Erin, I have a couple of questions about sea stars, including how did you start working with sea stars?
So prior to about a year and a half ago, I didn't do any invertebrate culture besides jellies, that was mostly what I was working on and fish. But we were contacted by the Sunflower Star Lab. And they kind of brought up that they were interested in doing some sunflowers star conservation work. And so we sort of hit the ground running from there and said, Well, it's time for us to learn some invertebrates. And I just kind of dove right in and then became obsessed with it. And now that's all I do with my time.
I make stars. What is your favorite part of what you do?
Oh, I come to work every day and feel like I learned something new or like my brain is just constantly going and I get to work with my hands.
this field really lends itself to people who can't sit still. So yeah. It's a really a very good fit for most of us.
We're a fidgety bunch.
Anxious. Yeah.
Whatever works for us.
Love it. Okay, cool. So let's talk about sea stars. What are they? We call them sea stars. They might be referred to as starfish in pop culture.
Are they all star shaped? Oh, that's a great,
that's an awesome question. Most people think of the five armed sea star when they think of sea stars but not all of them have five arms. They are all a typical like star burst shape. That's kind of like classic of anyone in the sea star family. But they could have more than five arms so that that doesn't remain the same between them.
How many arms can they have? What's the
the highest number of arms is actually a deep sea star I believe and it is the largest sea star in the world. It just beats out the pycnopodia or the sunflower star. I can't remember its name because we just seen it on ROVs. I am sure the name is out there and I just haven't memorized it. But that one's got about 25 And that's more than the max for the sunflower star. Normally it's more like 20-23 Something like that. So very cool.
Yeah. 23 arms seems
That's a lot to control.
I can make so many TikToks
I can't control my two arms. So I can't imagine. Yeah.
25 arms. What, do they have individual control over each of those arms?
Yeah, so they actually have little tiny tube feet that just cover each of their arms, all the two feet work individually. And then all the arms also work individually. So they are quite flexible and can move their arms wherever they need to go. They can crack open shells, they can escape predators, they can do backflips. Yeah, I see them doing yoga all the time. It's like I say, if they fall off a rock or something, and then are upside down, never fear because they can just start moving one of their crazy arms and they'll just like, launch themselves up over so yeah
I don't think I knew that. That's probably the best they've ever moved. But they just kind of flipped themselves.
Actually, that is a misconception that sea stars are not fast. They can move quite fast.
25 miles an hour
Not quite that fast, that would be terrifying. Some sea stars are on the slower side stuff like pycnopodia or the sunflower star or like crown of thorns stars, those really large predatory carnivorous stars. They will book it if there is food
They're pretty fast, I've done some time lapses around the aquarium kind of like thinking I could just leave the camera after we close and walk around and come back. I'm like, Oh, let's sea star is gone. Yeah, it's like 10 minutes is so far away now.
I don't know why I assumed that if they had more arms, they might move slower. But it doesn't sound that
on the physics level, I'm not sure either.
A lot more drag. Too many tube feet. Never thought about it.
So cool. Okay, so let's talk about their general anatomy. So we know they range in arm amount. But how do they function? Do they have a brain do they have a nervous system do they have a heart?
no brain? No heart, they do have a nervous system. And they have what's called a water vascular system. So that basically is pushing like nutrients and oxygen through this weird little series of like rings and canals in their body. And it also connects to their two feet so it helps locomotion and movement as well. It's really bizarre if you look at it, it's so different from what we're used to. It's kind of like our veins and arteries, but it serves the same purpose getting oxygen and nutrients to all of the organs in the sea star.
Yeah, cool. Um, what about their reproduction? How are they able to reproduce? And what are the stages of life of a sea star?
Yeah, so there's two like main types of reproduction see stars. They are both sexual reproduction where there will be a female with eggs male with sperm. Some see stars do what's called brooding so they actually hold on to their young and they're usually like, attached to them in some way. So we do have a couple species here that are brooding stars, which is pretty cool. Basket star. Maybe Yeah, basket stars do that the babies like hanging out in their body cavities. It's really gross and weird. But you do you do you have the
Happy Mother's Day.
And our morning sun stars and I think they used to be in the touch pools brood. There's a couple other species as well. Most of the ones I'm working with are broadcast spawners. So the sperm and the eggs are just released into the open ocean or in our case, an exhibit. And if the sperm makes its way to the egg, it gets fertilized and wallah. After that, you just get a free swimming larvae. And the larvae will just start kind of changing shape over time, how long it takes before it actually looks like a sea star really varies by the temperature of the water, the species that you're working with. But in general, the ones I'm working with are about a month. So over the course of a month, they go through all kinds of really weird phases. Yeah, yeah, it's like, there's bipinnaria, which is just a stage where it kind of looks like this weird little like two diamonds stacked on top of each other. And then there's one called brachiolaria, which looks like a Pokemon. There's just weird extensions coming out of it. And I'm like, What are you? It doesn't look anything like a sea star at any point during its free swimming phase.
So those are all when they are totally free swimming. Yes. what propels them in the water do they have like a flagella?
Not a flagella, but they do have these little like cilia. So if you look at them under a microscope, you can see like movement like this. They're propelling themselves that way. But they're not necessarily very fast.
And when they settle out of being free swimming, and they become sessile, is that are they star shaped at that point? Yes. sort of
close to star shaped.
It's not quite the same as like what you're thinking of. It's a little more bulbus, if that makes sense. Cute. Yeah, it's pretty adorable. I have to be honest, I'm probably a little bit biased, but it looks pretty cute. And it's kind of fascinating because in order to get them to that stage where they actually settle down and become a star, if you're working with them in captivity, they need a cue to tell them the environment is safe in order to do that. And so we've all had to figure out like what is going to make them feel safe so that they do that and
algae lullaby. Yeah,
I mean, it's different for every star. So with the sunflower stars, they really like sand that has been in the presence of an adult. And it's, it's bizarre and specific. But it makes sense. Because if you're a baby star, and there's large adult sunflower stars nearby, the environment must be safe. So why would you not settle?
They're like, someone grew up here, I'm probably fine. Yeah, how did you find that out?
Some of it's available in research papers, labs that have done stuff on sea stars. Otherwise, I just guess, based on where you find them in the ocean, if it's a tide pool, sea star, I'm going to put some algae you find in tide pools in there and say best of luck. And so far, it's worked pretty well.
That's awesome.
It's amazing how responsive to environmental cues all of these animals are. And it's things that we can't even perceive, you know, like, we don't think about what is potentially impacting a sea star settling or deciding somewhere safe until you try a bunch of different things. Yeah, that's, it's crazy to think about. And you have to have a certain kind of brain to think like a sea star to make the field.
And I think that's why people kind of just think, well, they don't have a brain so they don't like feel anything. And it's like, they actually do see stimulus and they feel water going by they can like sense currents. They can sense food and chemicals and all kinds of stuff around. They just don't process it the way we do because they don't have a centralized brain. But that does not mean they don't feel things
True, same sister.
Awesome. Well, how do they eat and what do they typically eat? Depends probably on the species
It does totally depend on the species. If you're talking about something like a basket star, it's catching stuff that's kind of floating by in the water. But the typical stars, we're thinking about that claim to the bottom of like the sea floor, or in tide pools, because they're on the bottom and they're not great swimmers, okay, they don't swim at all. They're not catching fish. They're eating things like clams, mussels, oysters, very slow shrimp, if they can find anything that they can kind of get their little to feed on that's on the bottom, they will eat. And there's a couple of different ways that sea stars eat. You can do the filter feeding method, like the basket stars. If you are very large, like a sunflower star, you just swallow it whole. And down it goes. It's really kind of terrifying.
It's sucha nice name sunflower star
I know and then you meet them. And you're like, You're terrifying. And you're probably eat me if you wanted to.
If I was small enough, where you were big enough? Oh, yeah. Right.
Like your hand is so tasty. And the other way is the one that most people I think know about because it's so bizarre. For some stars. If they have a large like food item or something, they can't quite fit into their body cavity. Their stomach comes out of their body, and it like surrounds the food and starts digestion outside of the actual body. Like can you imagine? I'm so glad we don't have that. It'd be so embarrassing
at dinner. out to restaurants. Sorry, I
can't I'm actually really full. So I'm just gonna just swallow your entire meal whole. No, it would be interesting. It would make for some really weird social etiquette situations.
I would agree. Yeah.
What species of stars might we commonly see doing that
So ochre stars, that's one around here that you'll usually see their stomach out if they're eating, if you're lucky enough to come touch them in our like touch tank and they've just gotten five, you'll see their stomachs out. It's fascinating, but it looks about what you'd think it would look like. Don't expect anything pretty. Touch. Really?
Depends on your definition of pretty.
Yeah, pretty. Beauty is in the eye of the beholder
Cool. Do they have eyes? Did I ask that already
Not yet. I should have talked about that when we were talking about parts of their body, but they have eye spots. So they can sense light and dark. So they'll see shadows will see stuff passing over. But they're not seeing in color. They're not seeing like defined shapes or detail.
Yeah, seems like they're very similar. Similar to the sea jelly. Are they related?
They are not related. sea jellies are cnidarians. So those are still invertebrates. So they do have that in common. But the cnidarians are a completely different group of animals.
What are they closely related to?
They are very closely related to sea urchins and sea cucumbers.
Which also do stomach eating. So there's a tie in I've seen a sea cucumber do that before, so it makes sense. Yeah.
Was it beautiful?
It was something to behold. But it was unique. Yes, I had never
They have a great personality.
Don't look at what they look like. Really good personality. Do Urchins ever do stomach eating? Like inverting their stomach?
No, no, they've actually got these really disturbing looking little rasping teeth. Almost, they're not technically teeth, but they basically munch on algae. And so even though they look like a sarlacc pit basically it's actually just herbivorous and eating like plants. Basically the
They're really cool when you when you walk around the aquarium, you might see an urchin up against the acrylic on some of the exhibitis and you can see that little mouth those little teeth
Yeah it's justm going as the Aquarist cries in the background of all the scratches. But
he's eaten something. So yeah, they
have no need for their stomach coming out they've got a little bit better feeding method. I think
I've also seen some of our Urchins wearing hats around the hat. Oh, that's said, Yes,
I get this question all the time. Yes, it's not because they are fancy and fashionable.
It might be.
I mean, it might be I can't really sure. Maybe I should ask before I comment. But they do like to feel hidden. It's kind of a good way to protect from predators, anything that might want to have a go at them. So they'll stack stuff on top of them to kind of disguise their own body. And if that happens to be a cowboy hat, they will put it on
I feel safer in this.
Out in the wild, you will not see the cowboy hat it will be algae and rocks
Unless Unless someone put a cowboy hat in the wild, which we do not endorse, definitely do not recommend. Keep your cowboy hats out of the ocean, please and
away from those urchins. But if they are wearing a hat of some sort, typically those are also attached by tube feet, correct?
Yes.
So that's how they're pretty similar to see stars. But, you know, anatomically, they don't look very similar. Is their skeletal structure similar? Like where can you see the relationship
Really biggest thing is A they have tube feet, which they both share. And then they're what's called radially symmetrical. So you can basically like divide their body and it's going to be exactly the same on either side. So that's a big like, that's what echinoderms are known for.
And what about if they lose a limb? Are they still symmetrical? Will they become symmetrical again?
one day far far in the future. Yes, they can regenerate limbs, just the arms, as long as their little like central disc where a lot of their organs is not damaged, they will regenerate. If that gets damaged, they will not and they will likely succumb to an infection or something like that. But yeah.
Fascinating. What is the sea star's role in their ecosystem? What are they kind of out there to do besides just vibe and spit out their stomac
They are all sea stars are predators. They're carnivorous. And so they're mostly eating urchins or again, like bivalves, other things on the bottom, but because they go after urchins it's really good for keeping those populations in balance. And here that's super relevant because we need our kelp forests to be healthy. And if we have too many urchins, and nobody's eating them, unfortunately, we're gonna lose the kelp. Other places in the world like tropical Pacific where they don't have that stuff you could have like a crown of thorns star specifically eats coral, other stars munch on algae that grows on rocks, or they'll just eat stuff they find in the bottom in the sand.
How does the sea star eat a sea urchin? That seems like a very soft bodied thing eating a very pokey thing?
You are right. Luckily, their skin is pretty like leathery and tough. So they don't really have an issue with the spines, but they essentially crack them open. They're a lot stronger than they look. Ah, yeah, especially when you're looking at a big star like a sunflower star, they can pull on you or really strongly if they want, and they'll basically just crush the sea urchin until they can get to the good bits inside.
I think through this podcast, we're talking a lot about keystone species and animals and their ecosystems that you know, eat other animals that keep populations in check. And sea urchins seem to be a reoccurring problem for a lot of our ecosystems.
If the environment is perfect, everything's in balance, They're not an issue. Everything kind of has its place in a perfect ecosystem, but just because their populations have boomed because they're predators are unfortunately going away. Now they're causing an issue for a lot of their, their ecosystem, adaptable animals they are they're pretty tough. They're a lot tougher than we give them credit for. And they can adapt to varying environments. So is it
Is it true that sea urchins can go into sort of a dormant mode if there's no food around?
Yeah, we call them like zombie urchins. Essentially, we unfortunately have them here in Long Beach. If you go out to the breakwall, and you're ever diving and lucky enough to see sea urchins, those things are essentially empty. We've brought them back before and they've had empty gonads, they're not reproducing, which is also not great for them. But yeah, because there's a scarcity of food because they already ate at all. They just kind of go into this weird zombie mode where they're not like their body processes aren't really going. And it's an attempt to like, save themselves so that if eventually they find food again, they can kind of restart and regenerate.
So if you collected them and fed them, would they be back to normal?
they should eventually as long as you like stuffed them with kelp. But it is a problem. If you're talking about like for humans, if you're trying to go out and get like a seafood for eating, they're not going to have anything you want to eat in there. It's basically just a shell of an urchin at that point. So it could be an eventual problem for fisheries as well.
That's interesting. What species of urchin I know we're talking a little bit more like urchins than stars. Oh, same, same. They're all kinds echinoderms. So this is now our echinoderms podcast. But for the sea urchins that we have here that specifically graze on the kelp and are more responsible for over grazing, what species would that be?
That would be the purple urchin. And we do have other species here. And a lot of people kind of look at them and think, Oh, that was those are bad. We're mostly referring to the purples. Those are the ones who, whose populations have really gotten out of control. We also have a very large a beautiful one. It's called the red sea urchin, they're
Pretty
Please don't go smash it. We do still need sea urchins. And those are a little bit different in terms of what they graze on. It's mostly the purple urchins that are just overtaking the giant kelp
Are there. Is there a species of sea star that more specifically preys on urchins? That is maybe somewhat of a keystone species?
Yeah, that would be the sunflower star.
Ah, the one that has problems.
the one that we need and is unfortunately, barely hanging on.
That's actually perfect timing. Let's get into that. Let's, um, I know we're participating in a conservation effort for the sunflower star, which the scientific name is
pycnopodia helianthoides
I won't try and say that, but it sounds very fun to say
it is basically saying many feet, many feet.
They have tiny little feet,
but they're huge. Yeah, well, their feet aren't, aren't huge. Yeah, but
they are huge. They get absolutely massive. They're in the top like five largest stars in the world. They're very heavy. The largest one we have right now I'm not very good at like measuring, but it's
A couple feet in diameter. Okay, that's a pretty big star
are pretty hefty, too. Like they weigh a lot.
That's funny, I guess if you don't think about what a sea star weighs, because they're usually attached to something or underwater or both.
Please don't pick them up. Never find out how much sea stars weigh. Just trust us. They're quite happy, especially
if they are trying to eat your hands. Like let's especially not pick them up. That's not good for anyone, not you not the star.
And I mean, it's unfortunately really unlikely you'll see one here anymore. We lost about 99% of their population in California due to something called sea star wasting disease. So a huge amount of sea stars, not just the sunflower stars died because of that. But because they're such voracious or urchin predators. We really saw that that was the time that the imbalance started when we lost the sunflower stars.
Those was purple sea urchins man. Right? What type of infectious process is sea star wasting disease?
So unfortunately, we don't have it pinpointed. Yeah, there's a theory it might be a virus. But we haven't narrowed it down yet. And until you actually, like, get a hold of that. We can't make it go away. Yeah. And that's kind of the unfortunate part is we can't treat it right now. Because we don't know what it is
Yeah. It seems to be a fairly recent occurrence.
I think the first wasting like large wasting we saw here started in the early 2010s.
Wow, that is super recent. Yeah. So we don't quite know what is going on with them. But what are the typical symptoms that you might see? Or do you just kind of find dead stars?
A little bit of both. But if you find a star that's still alive, that has sea star wasting, it's like skin is literally just melting. Yeah, the whole thing just melts until there is nothing but a pile of goo left. It's horrifying. This Yeah, literally
wasting. Yeah. Wow. Yeah. That's horrifying.
That's interesting. I wonder what I mean, I'm sure we'll find out at some point
why there are people working on that and really trying to identify it before we lose some sea star species forever.
So what is the aquarium doing to assist with that effort?
Yeah, so we're part of the pycnopodia recovery working group. So it's a collaborative effort between aquariums labs and nonprofits like the sunflower star lab I mentioned earlier. And we're trying to figure out how can we reproduce sunflower stars in captive environments, whether it's a laboratory or an aquarium, and then eventually be able to contribute to outplanting them back to the wild. So we're still in the stage of just working on culture and like perfecting our techniques. It's a pretty small group of us right now. But the thought is, once we really nail that down and have like, this is how you do this successfully. We'll share it with other people. Everyone can get on board with this project. And then a couple years down the road, once we figured out all the rules and regulations you have to go through to do our planning work. Maybe one day we can put them back out into the wild and kind of restore the population here. Yeah, so
Save the sea stars
sounds as though we at least know that they need an adult sunflower stars presence to settle you know, like, it sounds like there's some we're super
lucky because Friday Harbor Labs up in Washington, they have been doing this sunflower star work and so they are actually two or three years into reproducing these stars. So they've gone through it a few times and they've gotten a really good technique down and we're just trying to kind of adapt it to a cool aquariums. Laboratories are very different spaces, they're set up quite differently and can be a lot cleaner. If anyone's been behind the scenes at an aquarium, it is not sterile in any possible way. So figuring out how can we adapt the technique that's already been used for a few years by them to do it in aquariums?
That's it. So are they having luck fully, like raising any?
Yeah, actually, they had some two year olds this year that actually spawned, which is fantastic. Because once you get something, you've raised a spawn, you know that it's healthy, it's not going to sign if it's not doing well. So yeah,
that's interesting. What, how many offspring do they create at once?
Oh, just 1000s and 1000s. I mean, you'll get more than you could ever do anything with, unfortunately, they do cannibalize each other. You know, it happens the wild is sort of, it's pretty sadly,
we need 1000s of individual habitats for every
honestly, yesterday, I actually bought a little bead box for separating these out for crafts. And we're going to try raising individuals, once they get to a certain size, we'll separate them out into those little boxes to try and keep them from eating each other. But
Will they just put be tiny sunflower star shapes? Yeah, they'll
go through the same larval like period, like the freestyling. I talked about the diamond. Alien. Yeah. But eventually, they will look like teeny, tiny sea stars. And they are pretty ferocious right away, you have to feed them baby urchins. So when you're doing this culture, you have to do what's called co-culture and at the same time, produce urchins for them to eat.
We talked a little bit about that, too, with Josh, and we talked about jellies how he was raising jellies to feed other jellies at the same time, because yeah, that's what they eat. Yeah, go such
a strange part of our job that people don't necessarily think about. And I know you have some experience with our live food systems as well. And you were one of our live foods aquarist for a while. And that means raising live food that our animals can eat, because a lot of larval animals simply won't eat things that are already dead, or they don't recognize as food. Yeah, it takes maybe brine shrimp or misids, or all of those different little tiny organisms. Yep. And it's dependent on size too. It's like you need multiple sizes of things. Because you might have something that's too small to eat brine shrimp, and there's a lot of behind the scenes work that goes into doing any type of culture that I think a lot of people don't see.
It's fascinating. Cool. Well, with that, we have a couple of questions from social media to ask you. And I think you covered some of them too, even. But how many species of sea stars are there?
So there are approximately 2000 species? Wow, it's a lot and they exist in pretty much all the world's oceans cold temperate, tropical, you can find them just about everywhere. And there's some in the deep, there's some near shore, there's some tide pool, you can find them everywhere.
Very cool. How many do we have here at the Aquarium? How many species I want to ask specific of ours.
I'm gonna just do an approximate if that's okay. I would say about 15. We've got a pretty large number of species here, which is awesome.
And then I know you work closely with sunflower stars. But do you have a favorite?
I love the sunflower. There's actually one called a morning sun star. It's so Solaster is the like genus name, I encourage you to go look it up. They come in a couple different colors, and they're quite beautiful. And we have some blue ones here with like Pink Lining. Yeah, and they are gorgeous. And they're one of those stars that brood. So it's always fun if we see like little weird babies hanging to them. At some point, I'd love to move towards working with breeding stars, but I only have so many hours
in the day. Unfortunately, sunflower stars, I'm guessing are not a breeding they are the
broadcast spawn. Oh, so Yeah, they'll release the sperm and eggs for us go do
you think you're well figured out? I did parenting styles
for different species. Okay, whatever works for them. I want to ask a question. That is not a social media question. But what is a basket star? Those things look
crazy. Yeah, so they're a different type of star completely. They're not like a traditional star, obviously. But they're much more like flexible and have all these little arms that stick out. And that's so they can catch stuff from the water. So in general, they do still have the same like sea star anatomy, but they also have these like open canals on the side. And that's where the babies actually like hanging out is in those weird little canals in their body. So they're a bizarre star. But yeah, their arms are typically super long and just covered and all kinds of frills, so they have more surface area to catch stuff with.
Um, how do you tell the difference between a male star and a female star?
Unfortunately, you cannot that would make my job wait. But yeah, you cannot tell until you actually spawn them and then the sperm and the eggs have a pretty good difference between their appearance. So at that point, you can tell I guess you could technically maybe try doing an ultrasound and see if you can see it that way. But even then I'm not sure how clear that picture would be. So yeah, you just have to hope for the best that you'll have at least one of each. Yeah.
When I was in college, I remember dissecting sea star and just being shocked by how all the gonads are stead million squiggles inside of the arms. Yeah, and I don't think even looking at them internally. I could tell which one was.
Just hear me say squiggles. It was probably a male. Oh, good. Yeah. See now this firm looks very squiggly. That's the perfect word for it. The eggs are more like a typical egg mass. Yeah, they come out as just like goo essentially by and they're usually a different color. The sperm is typically why and the eggs it depends on what species we're talking about. orange, pink, yellow, something like that. Was just
that thing was jam packed full of squiggles. So it was a boy.
That's amazing. Um, okay, we answered a lot of the let's see, oh, what senses do they have? Can they feel touch smell? Are they psychic?
I don't know about psychic powers, that would be kind of amazing. But they can feel like stimulus. They can feel changes in water temperature, like currents going by, they can taste with their little tube feet. So if there's like a food item nearby, they're gonna be able to taste that in the water and then make their way over to it and taste it once they touch it. So yeah, that's pretty cool.
Do they have food preferences from your experience? Oh,
okay. This is a hard one out in the wild. No, because those rules don't exist. You gotta eat what you got to eat.
I found something out here. That definitely
happens. I've definitely had the sunflower stars if I hand them something they're like, but why No. And then they'll just like unfurl their arm and drop it on the bottom. Yeah, so there are definitely food preferences. Once you're talking about an animal that has all the luxuries of a life at the aquarium, and
they're given choices they will develop from Yes, they
were really really really like herring, which is not something they would eat in the wild because even they are not fast enough to catch a herring unless it falls to the bottom and dies. But they love it. They think it's the best thing they've ever had. So they're pretty fatty too right in high protein. Yeah, they are. It's good for them to eat. It's not something that's bad for them, but they definitely have a preference right now.
It's like a meatball sub just fell in your lap. I will eat this. This is great. What are some typical predators that a sea star might have other sea stars? The most prevalent thing though, I would say
so and some of them are more like predatory than others, like the larger stars tend to be a lot more like I'm gonna eat other sea stars. But even again, as juveniles the sunflower stars will eat each other. And I'm sure that's the case for other species as well. So typically, it's others other sea stars.
We don't typically eat any type of sea star do we? Yeah, some
people do. You can eat them like dried like jerky style. Yeah.
I've never thought of that in my life.
Definitely encourage you to go for a sea star species that's very abundant in your area. If you do like to eat see stars. But more typically, the way we see humans use them is dried out as like decoration. You can see them in like if you go to the beach and go to the gift shops. You'll see them just hanging up as like ornaments or just stuff to put around. So definitely discouraged gonna say buying see stars in that fashion. It's same with corals. We see corals kind of dried out like that as well. And they'll just look white.
Yeah, it's detrimental to their habitat. It is. Yeah.
So see stars and people tend to be their biggest issue.
Yes, human caused issues. Anthropogenic issues are greatly affecting sea stars right now.
Some of them are very brightly colored, and it makes me wonder, are they poisonous? Do they have a somatic coloration? Are they telling anyone not to eat them?
That's a super good question. No sea stars, to my knowledge are poisonous. But there are venomous sea stars. So usually, the way I tell the difference is poison is something you're ingesting. So it like with puffers. If you eat a puffer fish, you might get poisoning because they have like a toxin that's inside of their body, but because you've ingested it, but if it bit you, it's not going to do anything to you because they're not venomous. So the crown of thorns Seastar is very, very venomous. It's got all these spikes coming off of its body, like most see stars do, but those have a little venom gland in them. So if it picks you, you will have a very bad time. If you eat it, you're probably also not going to have a good time, but it's not going to be for the reason that it's poisoning you. So yeah, they are venomous, not poisonous.
What are some precautions you have to take with working with a venomous animal?
Oh a lot usually you have somebody else with you like working with a venomous animal alone is usually not recommended, just in case like things happen. Good
idea. Yeah,
you usually want to have that we do have emergency protocols for any what we considered dangerous animals. So not just that I venonmous things but things like sharks, anything that can cause bodily harm. We all have to kind of be aware of medical stuff we can do to extend the chance of someone making it to the hospital in case they're working with an animal like that. With see stars usually wearing thick gloves and making sure that if you need to pick them up, you either use a net or if you have to use your hands you do it from the bottom where the two feet are and not just grab them for the Yeah,
that would be less than ideal for you. Yeah, the crown of thorns from the top.
Yeah. If people get stung, it's because they're walking around on coral reefs where they're found and they step on them with bare feet or sit on them. A really a good rule of thumb when you're in those areas don't step or sit on anything because you're likely stepping on a coral anyway, they also coexist with stone fish, you really don't want to step on those. So yeah, just be responsible. Try and just swim around if you're in an area where something like the crown of thorns exist.
Do we have one year?
We sure do. We've got one in our coral predators exhibit along with our parrot fish and other things that like to munch on corals.
And don't think I appreciated that I'm gonna have to go Yeah, it blends
in really well, with the backdrop. So you have to do a little hunt for it. But there are some I think there's two in there right now. Okay.
Yeah, we have stars in every gallery. We do. Yeah.
And all of them are Jen. She's a star. Thank you.
How can you tell how old they are?
Unfortunately, you can't. I wish you could. Yeah, there's no tree rings to go with, like, you can age sharks with like, rings on their body. But we don't have those receipts are so it's mostly a guess for a lot of them. We think some of them can live like 35 plus years. Wow, I think this largest sunflower stars we haven't house had been here since before we open. So they've got to be at least 25. If not more than that. So yeah, we think they can live a pretty long time for what invertebrates live. But we're not 100% Sure.
What might an old geriatric sea star look like
might have some damage to like its surface like it's skin, if you will, might have some like abrasions from life again, stuff or just life battering you down as it does.
All of us, even stars.
And typically, if you see one that's like really big for the species, that's probably an indicator that it is very mature.
So do they have a terminal size? Will they stop growing at a certain size? Or do they grow in depth now
they just keep growing and delicately until they are taken out? It's
a really big guy would be probably a pretty old animal. Oh, yeah. You said that we have sunflower stars that have been here since before the aquarium opened, which means that they were here before sea star wasting disease really took hold notion. So does that make them a very genetically valuable sort of
resource? That is an awesome question, because we actually did donate tissue to a geneticist who is running are trying to answer those questions and running those tests. So we're trying to figure out, is there a difference between captive species who are not exposed? Is there a difference between the ones that survived in the wild? And is there a difference between the Alaska populations and the Southern California populations where there was less die off up north? And we wonder if that's a genetic thing? If that's the thing? Yeah, it could be a number of factors. So there is somebody working on that right now. And we're kind of awaiting the answers. So I'm really curious to see what comes with that.
That'll be interesting. And it's nice that we have these animals that have never been touched by that disease so that we sort of have this reservoir of genetic got very lucky that
we were untouched by sea star wasting.
Do they ever change color can in a sea start to have a chromatophores? Does it unfortunately, no,
they cannot change color. Once they've got a color. They've got it. But you do see color variation even in the same species. So like bat stars, for example, every color of the rainbow essentially, you can find them in any color. And sometimes they have multi colors, but the color doesn't change once it's their tie dye.
I feel like I've seen a lot of sea stars that feel like they really stand out from whatever they're, you know, like their orange, the red, the blue. Why don't they try harder?
In fairness, not a lot of stuff eats them besides other stars. So I don't think they're in quite as much worry about getting predated on by like birds or something you hide from
those evolutionary pressures maybe just never existed.
Exactly. Beautiful instead. Yeah,
it might be nice to have no worry.
I'm just besides a horrible disease, everything's fine. I wonder what the evolutionary pressure was to make them so colorful in that case, you know, yeah. I've
always wondered if it might be like for mating, I'm not sure. But they I mean, I don't think they see color, as far as I know. So I'm not sure if they would see like a different shade of
black or something and be like, Wow, that's the one I
wore. Yeah. I wish I wish I knew why they were that way. But for now, let's just say our own enjoyment.
Yeah. They look so beautiful. And our coastal corner touch lab. It's like an underwater garden. It's just gorgeous. And
that's where we have the most diversity of species because the tide pools are where you'll generally find that so we've got a lot of our sea star species and coastal corner.
They're very cool. We answered this earlier, but is there a special name for their little sucker feet? Yeah, they're called tube feet to pee to how many can they have?
Oh my gosh, I never counted so many. Tomorrow they'll be counting. It will depend on the size of the star obviously like stuff like this sunflower Stars are gonna have way more than like a bat star.
Or they're two feet variable in size based on like placement on their body or just based on size of the stars. I usually just sighs Yeah, but they're all kind of the same on the individual.
Yeah, very cool, interesting. Okay, our last question is how can the public help see stars, especially with this terrible disease facing them?
Excellent question. So we have a theory that some of these diseases that are popping up in the ocean are due to manmade problems. So things like climate change, ocean acidification. So if there's anything you and your individual life can do to sort of like, lower your carbon output, I would say that's going to be a huge help for sea stars. Definitely don't buy stuff in gifts shops that you think might have been alive at one point. That would be very helpful for sea stars. And I know a lot of people eat urchin, please eat purple urgent, if you can find some that have nice ripe gonads and aren't zombies then? Go for it by Yeah, purple only purple only please don't eat. You can eat reds, but do it in a sustainable manner. Yeah, purple only?
Do you this is one more question for you. Do you know if sea stars won't eat urchins that are zombie urchins? I know sea otters? Typically won't, they'll realize there's nothing in there and then they won't
go Yeah, cuz I mean, there's nothing nutritionally that it's going to offer them and it takes time and energy to hunt for food, even for sea stars that we think of as kind of lazier animals. So why waste your energy? If you can sense that there's nothing there nutritionally for you to eat? is fair, is
there anything that we missed that you would like to share about sea stars, or
they're amazing. They really are. I would just say I super encouraged people to dig into invertebrates. It doesn't have to be sea stars, but they're very bizarre, they're very different from us. But because they don't have a face that we can kind of recognize, we tend to just kind of look at them as this weird alien thing, and not really learn anything about them, or think of them as cute or fun or whatever. And I encourage you to dig into inverts, there's actually some really cool stuff out there. And just because it's weird and different, doesn't mean it's not amazing. At the same time, just because it's
not cute and cuddly like a sea otter doesn't mean, there's not a lot to learn. The Otters
are also amazing. And they're kind of I mean, especially with the sunflower stars, they're sharing an ecosystem. So in a lot of ways, they probably rely on each other to keep things in check. So all of it all of it's important to
how connected it is. It's been a really interesting time talking to people. But like, Josh, I didn't know anything about jellies. Yeah. And every time Josh was like, This is how jellies live. I was like, What are you talking? You know? And then to hear that see, stars at some point are like two little weird diamonds that are swimming around. That's so strange to me. Yeah,
you just can just open my phone. It's out of control full of pictures of larval sea star pics. It's,
these are my baby pics. Yes, people are like,
minds full of tadpoles. So perfect. So you understand? Yes, the same kind of feeling. invertebrates are super cool. Everyone should learn more about them. People should care more about them in general. And I know that we have the big charismatic animals. But I've learned more about sea stars today than I've ever known in my life. And to know that sunflower stars can basically save an ecosystem. Yeah, they're out there. That's, that's what we need. Yeah, more stars, and really to do conservation work like we're trying to do and like a lot of organizations are doing, you need support. You need monetary support. You need like just regular support from people saying, Hey, we care about this. That's how you get science done. And so since invertebrates aren't necessarily the most popular Historically, it's been really hard to sort of get conservation projects involving them going. But now like the ball is sort of rolling on them on abalone, which I'm sure you're going to talk about at some point if you haven't already. So definitely look up maybe some nonprofits that are working on Invertebrate Conservation projects, and try and support them if you can, too. Exciting.
All right, thank you so much, Jen. Yes, thanks, everyone. Aquarium of the Podcific is brought to you by Aquarium of the Pacific a 501 C three nonprofit organization In 2023 the Aquarium celebrates 25 years of connecting millions of people worldwide to the beauty and wonder of our ocean planet. Head to aquariumofpacific.org to learn more about our 25th anniversary celebration. Keep up with the aquarium on social media @aquariumpacific on TikTok, Instagram, Facebook, Twitter and LinkedIn.
This podcast is produced by Erin Lundy, Madeline Walden and Scott Shaw. Our music is by Andrew Reitsma and our podcast art is by Brandi Kenney. Special thanks to Cecile Fisher and Anitza Valles and our audio visual and education departments. And to all of our amazing podcast guests for taking time out of their day to talk about the important work that they do. I'd cific wouldn't be possible without the support of the aquarium donors, members, guests and supporters. Thanks for listening
