Hello and welcome back Shark. Here is to another episode of
Deep Dives with sharks. My name is Alex.
I am the host here. I have not wandered off into the
ocean to pet a shark, at least not yet.
There's still time. So there's shark safety news
episode as that's where the rotation goes.
Since most of you guys are here for the sharks, I'm going to do
a few episodes with safety and news, Buffer movie review,
Aquarium review, different episode.
Then do a few episodes with three sharks.
To be clear, there's going to be like 1 buffer episode.
I'm not going to like just throw a bunch of random episodes in
the middle and then talk about sharks more, but something to
kind of split it up. I'm trying to give everyone a
little bit of what they like. Unless you like all of it, then
in which case you get all of it. So when, when?
But to stay at the date on everything that is Deep Dives
with Sharks, hit the follow button on Spotify, Apple Music,
Instagram, Twitch, YouTube, Amazon Music, or anywhere else
that you get your podcast at Deep Dives with Sharks.
Now we're going to jump kind of right into the shark that we
have for today, which is going to be the Port Jackson shark.
And these sharks are one that pop into my mind frequently, but
I don't know a lot about them. They're absolutely beautiful and
I was really hyped to do this episode.
So to start at the Port Jackson shark is part of the hetero
Dante Day family, which is hard to say, which only includes
other bullhead sharks. So they could have just called
it the Bullhead shark family, but that'd be a little too easy.
They typically grow up to 1.65 meters or 5.5 feet long, which
is a little shorter than me, so I'll take that as a win.
They have an interesting coloration that has a yellowish
brown base with brown stripes that form throughout their body,
but it comes in varying patterns.
They'll also have some white on them, often around the ridges
that sit above their eyes. They have a long tall head that
leads into a brown snout. Their eyes are high set and have
ridges that are placed above them that trail back towards
their gills. Their pectoral fins lay flat on
their side and they appear to be rather large for their size.
They have two dorsal fins with the second being slightly
smaller than the first. The dorsal fins also have spines
on the front because they liked what the spiny dogfish was doing
with that look. Porcupines are also a pretty big
fan, so good to know they got a club now.
Their nose and mouth are rather freaky.
I was not prepared for their nostrils.
Face straight down and in between them is a row of teeth.
The front teeth are sharp while the back teeth are more blunt,
which helps with crushing. Their mouth is also about as
wide. It goes pretty much as about the
width of their head, but the teeth are only in the middle
kind of in between those nostrils and the the teeth are
just right. That's weird.
So straight up looking at a poor Jackson shark from above, they
look like a distinguished gentleman.
And then you get a view from below.
When it's the mouth of a clown from a horror movie.
It's honestly terrifying. It's rather weird that they
would go with this. I don't quite understand why
they'd want to do that, but you know, to each their own.
Now it's time to move away from the freakiness of them a bit and
also tell you that they are only found around Australia, but it's
believed that they are also around New Zealand.
Although the only specimen that was said to be caught in New
Zealand waters was not properly documented and scientists cannot
confirm a proper collection location.
Australia's confirmed New Zealand strong.
Maybe Canada? No, they're not really close to
Canada, sorry. But you can find them in the
Ripley's Aquarium of Canada. In America we have them in
Newport Aquarium and the Tennessee Aquarium.
I'd also like to real quick note that when I was looking this up,
Google listed the Newport Aquarium under both America and
Canada and I looked into it thinking, oh, maybe it's on the
border or something neat like that.
No, it's in Kentucky, which isn't really near the border at
all. So, you know, it's kind of
middle of the country ish. close enough to Canada, right?
But anyway, back on topic. They're mostly found around
southern Australia, venturing as far north as the York Sound.
But marine biologists have labeled those reports as
dubious, which is a pretty polite way of saying whoever
reported this is lying. But they're usually found around
Queensland, around southern Australia, and coming up into
the Central Coast of WA, which, another quick sidebar, I didn't
realize y'all literally named the western part of Australia WA
and caught it a day. Like, Americans saw we had a lot
of space and went, you know what?
Texas, California, Florida, Alaska, going to need y'all to
cover some real ground here. But Australians just went, yeah,
it's Australian, it's W WA. You know, you got to respect it.
That's actually pretty, pretty great.
Although you should have put it on the eastern side just to mess
with everyone, be kind of funny. We're going to go to WA.
Where is it? The east?
Great. Anyway, sorry, this is going to
be 90 minutes if I don't stop. The Port Jackson shark is a
bottom dwelling shark and is often found in depths of less
than 100 meters, which is 330 feet for those of us who can't
use the metric system because our country is weird.
It's a triple shot at the United States, Liberia and Myanmar.
So let's get together guys. Now the poor Jackson shark will
usually be in shallower waters of 100 meters, 330 feet or less,
but can explore further into depths of 275 meters.
Now real quick to have a little fun, I'm going to pause here,
see if anyone can convert that meters to feet themselves.
Anyone. Bueller.
It's going to be 902 feet.
So let me know if you all got that in the comments because I
definitely didn't Now also, you could have paused it there to
give yourself more time as well if you wanted.
So maybe next time we'll find out.
But the Port Jackson sharks, they tend to like rocks around
their habitat kind of like they really do like a good boulder, I
got to say. But they aren't opposed to
sandy, muddy or grass bed sea floors.
They're not too picky as other sharks are.
Now during the day, these sharks will hang out in caves or other
areas that have a flat floor shielding from the current so
they can rest. Because these boyos are
nocturnal, their nocturnal behaviors have been on display
in captivity as well as they were seen moving more and at the
night time especially the most between when it gets dark and
midnight. But then after midnight, their
activity would begin to diminish.
So it's kind of like how humans wake up and we're a little
groggy, but then we get a little bit more energy and then once it
hits about 3 or 4 in the afternoon, we tend to kind of
crash a little bit and need a little pick me up or a little
nap. Same thing happens with Port
Jackson sharks. Their activity diminishes after
midnight. Now, the Port Jackson shark also
migrates annually, which is a little bit confusing for a shark
that hangs out around 1 country and continent, which you got to
put a little respect on Australia's name.
It's both. So they migrate from the coastal
waters to bays and harbors along the coastline.
So not quite thousands of miles, but the salmon swim upstream,
and that's a migration. So it's not so much the distance
as much as doing it repeatedly at a certain time or for a
certain reason. And these guys tend to do that
for popping reasons, which is neat.
But something really interesting is that the Port Jackson shark
migration was tracked using Tri axial accelerometers.
That is such a hard word to say for someone that never has to
say that phrase. Tri axial accelerometers that
also gauge the sharks movement. I was trying to figure out a
great way to explain these in my own words, but looking on the
Wikipedia, they kind of nailed it just by saying they're very
similar to like Fitbit or smartwatches that track your
movement the same way. So just imagine we kind of
hooked up a Fitbit to a shark and called it a day, but it
allowed us to track where they went, how far they went, things
like that. Now the Port Jackson shark have
5 gills, similar to many sharks, but for some reason, the first
gill slit only has a single row of gill filament, while the
others contain double rows. Researchers are not quite sure
why the first has less, but the sharks also have a respiratory
accessory called a spherical that sits behind their eye.
So that's where they tend to breathe behind their eye, which
is interesting, but they also have lamellae which help.
It's where the oxygen goes to be used essentially.
Which to go in a little bit more in depth about that, the
lamellae use arteries, which I don't even know if I'm
pronouncing that right. They use arteries which carry
blood away from the heart to the rest of the body to deliver
oxygen throughout our shark. But these arteries push blood in
the opposite direction of the flow of water.
So when the water is coming into the gills, the blood is flowing
in the opposite direction, which does not mean out of the shark.
It just means like if the gills are going backwards or the flow
of water is going backwards, the blood is pumping towards the
head, if that makes sense. Now excuse me.
The whole point of this is to help oxygen dissolve into the
blood because they tend to live near the bottom of the ocean.
They like the sea floor. So if they're going to be
staying on the sea floor, then they don't have quite as much
oxygen as the upper water column.
So they need to get as much oxygen into their gills as they
can. So having this resistance or
keeping the water and blood kind of in the same spot will help to
get the blood diffused into or the oxygen diffused into the
blood. So that way the shark can then
put the oxygen throughout its body.
That was very technical and very sciency.
That might be a little bit complicated for some listeners.
So if you didn't quite understand that, don't worry.
Eventually we'll get the middle school, high school, college bio
and it'll click somewhere there because it did not click for me
until much later. But hey, we got here.
I can explain it somewhat. That's exciting.
But anyway, so another neat thing about the Port Jackson
shark is that they can eat and breathe at the same time feet.
Many sharks cannot. You'll often see shark gills
flare when they're eating, causing them to have to inhale
and then eat. One of the greatest examples is
great whites. When you see them eating on like
Shark Week, you'll see them go to Turd and you'll see their
Garrett gills just flare out. So yeah, Port Jackson sharks
don't have to do that. They're just built different and
they can eat and breathe all at once.
So they'll be able to eat and then hold their breath.
Now I do keep thinking about how I need to wrap this shark up
because at this point in my research, I was on three hours
of research and I was on page 4 already, which usually it it's
not that much, but they just there's so many cool things
about this shark. And with that being said, they
have AJ shaped stomach. So like the letter J it, it
hooks Now, food can pass through really easily.
But if something that is not food tries to pass through, the
shark is able to either cough it up or if they just can't get it
out, they'll just turn their stomach inside out casually.
You know, which I wonder if it's kind of more like when you're
surprised by a burp that comes out or if it's like on command,
just oh, excuse me, I appear to have turned my stomach inside
out, which it's not really great for dinner parties.
But I mean, even if they did that in front of you, you'd
really only find sea urchins, mollusk fishes and other
crustaceans because that's pretty much their entire diet.
Now. Their favorite though, is Black
Sea urchins. They have been seen to go a
little bit nutty about those, so they do like Black Sea urchins
the most. Their sharp front teeth help to
catch and eat fish that have the little softer bits, while
mollusks and urchins that have the harder bits get worn down by
the blunt back teeth. So their teeth are designed to
help with really all of their dietary needs.
Adult Port Jackson sharks often group up to rest in caves, often
based on their size and boys club versus Girls Club.
But the kids aren't all right and prefer to be solitary
because they have trust issues or something.
I'm not quite sure. But evidently juvenile Port
Jackson sharks can be trained very easily by aquarium staff in
captivity as they respond well to LED lights, bubbles and
sounds. So really any stimulus they
respond to now they also learn by watching other sharks.
So I'm kind of disappointed that there aren't, that they aren't
near the open ocean because I think it would be amazing to see
one of these goofballs breaching after watching great white do
it. Just be kind of funny just
seeing like a little small guys flopping around.
But anyway, now these sharks also pose no threat to humans,
although they should be absolutely feared because in
2011, a man was bit by 1 and it was so, so horrible.
The shark was latched onto his calf and the man swam to shore,
wasn't even bleeding. The teeth did not Pierce his
skin. They're pretty harmless and
humans tend not bother them. They're really only caught as
bycatch and not caught for sport or really anything else.
So they sometimes bite us very rarely, and when they do they
don't really hurt so. But don't go mess with poor
Jackson sharks. So there's going to be 1 that'll
mess you up now. Also, because of humans and poor
Jackson sharks not really beefing, they're listed as Least
Concern, but they do face a high egg mortality rate.
They do lay eggs, which is really cool, but evidently as
high as 89.1% of the eggs won't hatch.
And it's kind of a sad thing to end on for the Port Jackson
shark. So I feel a more fun thing would
be that their eggs are spiral shaped.
They kind of look like a big old drill bit.
There's a big spiral. So they're kind of fun looking.
So definitely worth looking into that.
But that is what I have for the Port Jackson shark.
Of course, if you have any questions, any corrections for
me or anything of that nature, you can send it over to me in
any of the DMS or in the comments, anything like that.
But moving on to our safety bit we have what if I find a shark
egg, which this information I got from sharktrust.org, which
is an amazing resource. Now, First off, you're more
likely to find a shark egg during low tide.
It's also when many things get washed ashore, but you could
still find one during high tide. Now, the website noted that you
should let someone know where you are going and what you're
going to be doing, especially if you're going shark teeth or
capsule hunting. It's just a great idea in case
something goes wrong. Nobody really knows what could
happen. Me and Goalie tend to like to
walk on beaches at night and when we were in California we
were walking over on Laguna Beach and did not realize that
when high tide comes in that the water can go up to the entire
beach. And thankfully we noticed that
the rock we were sitting on, the water was getting closer and
closer to it and figured, you know, we should probably get out
of here before we suddenly get trapped here.
It's a good idea. So thankfully everything was OK
because you're paying attention. But if we weren't, we could have
gotten stuck there and then someone wanted needed to come
save us or something like that. Not pretty great.
So just make sure you people know where you are so that way
if something happens, they can come find you.
Now you'll also want to have a stick or some kind of poker just
to ensure that you won't get bit stung aggressively cuddled by
something that didn't want you to move.
Its Heidi little seaweed spot. It's better to be safe than
sorry. You're also most likely not to
realize that you are looking at a shark egg as they're meant to
blend in with their environment. So if they're hooked onto that
seaweed that washed ashore, it won't have a quest marker over
it. With the mission save a shark
and a timer, it'll most likely just look like another leaf, but
in a Port Jackson sharks case it'll have a really twisty leaf
to it. So at least a little bit of
distinction there. Now it could also be an empty
egg case. So you'll want to check to see
if there's an embryo still inside.
You can do this by having really any light source nearby.
So if it's the daytime sun works great.
Having the light behind it helps a lot.
But sometimes it's really obvious that there's an embryo
still in there. So you don't need like a high
beam Searchlight to look for it. Sometimes you just simply need
to shine a phone light behind it and then you're good.
If it's empty you can put it back where you found it or
something like that. Some people feel like collecting
shark teeth is wrong and shark egg casings as well.
I'm torn because I have shark teeth that I found but I don't
take shells home or anything anymore.
I'm just not that into it. I also just want the teeth and
none of the sharks near me lay eggs so I'm not going to find a
case or I'm not going to just grab a baby hammerhead and take
it home. That's a horrible idea.
Now I did try to look into it to give you guys more information
to figure out what to do with a hatched egg and Google keeps
calling me a piece of garbage for taking an unhatched egg
home, which I have not and isn't even what I was asking.
So now all my search results results are how could you you
absolute monster and I don't need this.
So if anyone would like to enlighten me on if it's OK or
not to take sharks home, shark eggs not sharks, don't take
sharks home, shark eggs home, feel free to do so below.
But also I wanted to point out that while doing the research by
impulsivity had gotten the best of me because I got caught up on
a bullet point on the website, did not finish reading the
article before I started looking into other things, and started
being called garbage by Google. Only for the next bullet point
directly under the one that I got stuck on to say empty egg
cases are not known to have any secondary purpose.
They don't break down to form sand or offer habitat as some
shells do for hermit crabs. They also don't decompose to
form part of the strand line. Take him home.
I don't care. I hate it here.
I swear I spent like 20 minutes Googling.
Are you allowed to take hatched shark eggs home?
And the entire thing is like, do not take animals from wildlife.
Yeah I know I'm not going to do that.
Why are you yelling at me? So yeah, I guess it's OK.
I don't know. Don't try to do your own
research as well. Don't base everything that you
do off of what I say. I try to give good information,
but I probably get some of it wrong.
So please also look into it if you're thinking about doing
anything like that. But I thought it was funny.
I got yelled at by Google only for the next bullet point to
give me my answer. But back on topic, if you are to
find an egg case that is not empty, you want to try to get it
back in the water now. This does not mean you want to
absolutely throw it as far as you can.
There's a good chance it's going to get damaged or simply wash
back ashore again. You're not Jaden Daniels during
a 75 yard bomb to Terry Mclaurin.
It's just a little shark and it's delicate.
So you want to place it past the waves and anchor it to
something. Now most eggs aren't going to
have too many things you can utilize, you just got to kind of
put it somewhere. But skate eggs, which looks
similar, they have horns on them, so you can weigh it down
by the horns. Cat shark eggs tend to have
these long thingies on them called tendrils that you can
just tie to something, but others just wedging it gently
between some rocks will do. Now you need to be careful not
to smash, squish, or damage the egg in any way as they are
malleable. So they can be a little squishy
and a little movable, pliable, anything like that.
But they're kind of similar to like chicken eggs, how they're
rather fragile, so they're not made of steel.
Chicken eggs break pretty easy. Shark eggs can also break rather
easily, but a little bit harder. Now you don't have to worry
about other sharks being territorial of their eggs like
birds are. Sharks often have babies and
then they go about their lives without the baby.
They just, it happens. They, they just abandoned
immediately. Now, many sharks like being in
the same areas as their offspring, but would definitely
fight their own child if it meant that they can get the food
that the kid was going for. It's a me versus them mentality.
Now. They won't come bite you because
you're holding an egg. It's not like a bird's going to
attack you or anything like that.
Or chickens pack people when they're trying to grab their
eggs. Sharks don't care that take the
egg, eat it. They don't care, don't eat a
shark egg. It would not be good.
Now, something to consider is what is around where you're
going to put the shark egg. Now, of course, you don't need
to find the most perfect spot ever.
Sometimes it'll do. But you want to find a place
where it'll be wedged nicely, not come loose too easily.
But also make sure that you don't wedge it in such a way
that the baby shark can't like escape and then it's kind of
stuck between the egg and a rock.
But also as well, you want to make sure that the egg isn't
going to get dislodged and wash back ashore.
And you also want to see if there's a horn shark nearby
that's just eating other shark eggs.
They do like to do that. I probably wouldn't leave the
egg in that buffet. That's just not going to be
helpful. Now, I'm not saying going a
whole cross country adventure to put a shark egg back in the
water. But I mean, hey, 30 feet a
different way, right? But you don't want to put it
somewhere where it can get damaged or where it can get
washed away. You want to try to anchor it
down nicely. But of course, once again, if
you're trying, you're doing your best and that's all we ask.
Now, I do mention this every safety segment, but don't put
yourself in danger to save a shark or a shark egg.
If it's low tide and you can get the egg into a nice outcropping
without having a wave slam you into a rock, go for it.
If it's hurricane force winds, it's downpouring.
There's 500 foot waves. Don't go try to save a shark egg
that that that's in God's hands at that point.
Also if you can see a shark egg in those conditions.
Might as well as quit your job. You know, you're a superhero at
that point and the world need to so go use your supervision to go
save somebody. All right, That's I don't know
how you'd see it in that condition, but my goodness.
But one thing I want to end on here is that Shark Trust is a
great resource to use and learn more about sharks, how to help
them, how to protect them around the world.
I highly recommend checking them out and any other source I've
used for the safety segments. All of them are pretty great
when it comes to answering your questions and going on with
that. But of course we've come to the
long-awaited part that I have not talked about in a long
while. It's the news.
So the first news story that I haven't got 2 for you today.
The first one is about cuttlefish and that the
cuttlefish ink may overwhelm shark's sense of smell.
And this is by sciencenews.org. So we're getting sciency today.
Sharks like eating cuttlefish sometimes and the cuttlefish got
pretty tired of it. Now their main defense is to
shoot ink at its attacker, similar to how squid do.
But their second defense is having a massive bone that takes
up like all of their body, but sharks still get through.
Technically it's a shell, but then whatever.
So the cuttlefish realized they have to evolve to get these
sharks away from them and decided that they're going to
have ink that is full of melanin that binds to smell receptors in
a shark's nose. Now the smell receptors are what
grant us the range that we can smell.
Now humans have about 850 smell receptors, so we can smell a lot
of different things. Fun fact, humans can smell rain
and wet dirt the best. Don't know why but we can.
It's from when we were nomads when we had to figure out where
water was. Anyway, I can go and do a whole
rant about this, but we're going to stay focused.
So we have 8:50. It helps us to smell a lot.
But sharks, they have 43 so they get a lot less.
But the scientists believe that these are fine-tuned for things
such as blood stress signals, other things fish have, and also
just kind of first survival. So they can also smell things
that tell them they need to get out of there immediately.
Now, the melanin in the cuttlefish ink binds the
receptors blocking other scents. But on top of that, there's a
chemical compound in the ink that makes sharks run off.
So having that fine tune, this kind of a disadvantage when,
which means that when the shark can't smell other things at the
time and they can only smell the smell that they don't like, then
they just kind of cause them to keep hightailing it away from
the cuttlefish, which is a pretty smart move by evolution
there because that just keeps going.
Which that also means that this compound could be used in shark
repellent or to help keep sharks away from certain areas,
Although that is rather controversial because it can
disturb the ecosystem by driving sharks elsewhere.
And more testing we need to be done to see how it could be used
if it can be used without damaging the entire ecosystem
because they also don't know how to affect other fish too.
So something to think about. But the next one that I have is
largest shark ever tagged by research group named contender
is swimming off of North Florida.
And this is reported by CBS News.
Now, one thing that irks me about these article titles is
that they tell you quite literally everything in the
headline. Like I don't know why they give
you the whole story in the headline, but I don't it anyway,
I'm not a journalist person, so I don't know.
I just talked about sharks. Now the largest shark ever
tagged is hanging out in North Florida.
Contender, a male great white shark was tagged by O search on
January 17th, 2025 around southern Georgia when he decided
that the coast was lame and he wanted to head out to see a bit
more, but then realized he didn't buy his lady shark some
Mickey ears. So he had to come back this way
because you know Disney World's right around the corner, might
as well head that way. Now Contender is 13.8 feet,
which is 4.2 meters in length and about 1653 lbs which is
749.8kg for the weight. Now O Search was able to take
some samples from Contender before releasing him.
This will help to see any genetic code, anything like
that, any DNA to see possibly how he got so big, how healthy
he is, etcetera, etcetera. But on top of that, the tag that
they put on him will last five years to track his location.
But unfortunately not many other metrics on him.
Now. You can also follow along with
Contender. You can download the O Search
app or follow it online and you can see other sharks, sea
turtles, whales that they have tagged.
I had a favorite shark, his name was Pico.
He was a Mako and that was tagged near Texas.
I must emphasize the word had as I still love him very much, but
his tag has not pinged since 2021 and that was AZ ping, which
means that it communicate with a satellite but it couldn't
provide a location. So I hope that the satellite tag
just ended and he's out there eating lots of yummy things and
doing all the great breeches. But that's what I have for this
episode. I want to thank you all once
again for listening and being here and hanging out.
Commenter DM your favorite shark fact and I may share a couple of
them on the start of the next episode, because I usually start
my episodes by rambling about nothing.
So might as well share some fun shark facts.
You can also follow along on Instagram for more updates.
I tend to update that the one that one the most deep dives
with sharks. But of course, you got twitch,
the tap link everything else that you can utilize to make
sure you find me wherever you can send in any comments,
questions or anything of the sort.
And of course, give us a rating on Spotify, Apple Music,
anywhere you listen to your podcast, because ratings
comments, everything of the sort do help to spread this even
more. So I thank you all for hanging
out listening and I will see you in the next one.
Take care.