Hello and welcome back shark Heroes to another episode of
deep dives with sharks. My name is Alex I am the host
here. I'm still the weird guy that
talks to you about sharks for however long this episode is
going to be. Now I asked at the beginning and
I believe the end of the last episode ran a couple polls and
the shark heroes have spoken. Y'all want more sharks?
So welcome to the first multi shark episode.
Now I plan on seeing how this one goes and if people tend to
like it, we can keep doing this. We can keep having a couple
sharks per episode, but if people want to go back to the
old ways, we can do that. And I also still have a couple
things that I'm working on the background, which I know I say
that a lot, but new things are coming.
I'm trying to keep this rolling, keep it developing and see what
sticks and what we're going to leave in the past.
But of course, you can follow along with all the updates on
Instagram at Deep Dives with Sharks and also hear me ramble
about pretty much nothing over on Twitch at Deep Dives with
Sharks as well. There you get to ask all your
sharky questions as well and anything like that.
But of course, I did finally get a question asked.
That brings us to our question corner.
So the young William wanted to know if a whale shark would be
able to leap out of their enclosure to Freedom or in
another tank like Destiny did in Finding Dory.
So First off, it's a great question and 2nd, unfortunately
they can't. They weigh about 35,000 to
75,000 lbs when they're fully grown and the power that would
take to get them fully out of the water would be insane.
Now these are very powerful sharks.
They do generate a lot of power from their tail, which is what
propelled propels them through the water, but they don't really
get enough speed out of that. They tend to move about 5 miles
an hour or less right in that range, so you need to be a lot
faster to get out of the water there.
If you've ever seen a video of a whale breaching from underwater
or a a shark, you'll notice that they're going pretty fast when
they hit the surface. So that gets their full body, or
at least most of it, out of the water.
Whale sharks don't really move that fast, so they'll kind of
just get to the top and then their nose will pop out.
And that that's about the best they got there, unfortunately.
But he also did want to know how they feed the whale sharks at
the Georgia Aquarium, especially since each whale shark has a
special diet. And it's kind of hard to control
if you're just throwing a whole bunch of krill in a tank and
hoping for the best. So they target train the whale
sharks. Now, the sharks will see the
target in the water and they'll come to that spot.
So from there, the staff will usually be on floating dinghies
and they'll dump some krill into the water in front of them and
they'll eat that up. But they also sometimes bottle
feed the sharks. Now, not the same way that we
would to a baby, but they'll send divers into the tank.
And at this point the sharks will come over because they
associate the food with divers, which is why you shouldn't feed
sharks in the wild in the wild. Sorry, that was weird.
But they'll have the square bottle with them.
They'll squirt some of the krill into the the water in front of
the sharks, usually timing it with when the shark is going to
inhale during their feeding. So that way they can get the
krill and the nutrients and whatever else they need from
that bottle into their system. Now, it's really cool to watch.
And I would highly recommend just taking an entire day
sitting at the Ocean Voyager exhibit in the Georgia Aquarium,
and then go back the next day and sit at the shark exhibit all
day. And if I say it enough times,
the Georgia Aquarium will acknowledge my existence and
they'll send a cease and desist. And I cannot wait.
But that, of course, is what I have for the correction corner.
And now without any more further ado, we're going to jump into
these sharks. The first one we have is
probably one of the most popular ever is the Great White Shark,
which I'm surprised it took this many episodes for this one to
come up. And I tried to make sure I
didn't do this as my first episode because I felt it was
too generic. So here we are, almost 30 if not
over in where we're doing the great white.
I've lost track of how many episodes I've done.
I should know this but off the top of my head I forgot but they
are the one of the most popular sharks in the world, especially
thanks to movies like Jaws and 47 Meters Down which if you're
curious about you can hear my analysis of Shameless plug in
earlier episodes. 47 Meters down was the last episode we did.
Now these sharks are part of the mackerel shark family and that
includes the Goblin and Mega mouth sharks.
The great white varies in size depending on biological gender
with males growing smaller than females.
Males tend to grow to be about 11 to 13 feet or 3.4 to 4 meters
and females grow to be about 15 to 16 feet or 4.6 to 4.9.
Now the largest individual documented is the world famous
large shark Deep Blue Marine biologist believe that she is
about 19 to 20 feet long and around 5.8 meters and many
divers get very excited when they see her and if you ever
look up a video of her, she's just absolutely stunning.
Great white sharks can grow to be about 2000kg or 4400 lbs but
of course weight varies depending on gender and genetic
factors. Not every great white is going
to grow up to 4000 lbs. They can live to be up to 70
years old, although many marine biologists do believe they can
live longer. It's tough to determine though,
as they've been unable to keep a great white in captivity, which
I'm going to talk a little bit more about later.
These sharks can be found all over the world.
They've been found in almost all coastal waters, but can be found
in larger density around the northeast United States,
California, South Africa, the Mediterranean, Chile, and Japan.
They tend to change between a variety of depths, ranging from
the surface all the way down to 1200 meters or 3900 feet.
They can use the depth as a benefit while hunting as they
are breech predators, meaning that they will attack prey from
below and catch them by surprise jumping out of the water.
Shark Week showcases this very well with their program Air
Jaws. The rendition of Air Jaws have
gotten more absurd as the years go on, but they aim to find new
ways of capturing a great white breaching from the water on
film. They tracked the data to find
the largest breach, which I do believe as of at least two shark
weeks ago was 15 feet. Now, I don't think I watched air
jaws this time because I kind of got tired of watching the same
thing over and over again, but I still think of the records 15
feet right now on on their their programs.
Now, the great whites are also migratory and will travel with
the seasons. They can tolerate colder waters
off of Canada during the summer, but we'll have to move South
when the winter comes and move to the southern hemisphere
because you know who likes the cold?
Not me. Not me at all.
Now they have been recorded traveling over 20,000
kilometers, or 12,000 miles, or 11,000 nautical miles, which I
just found out there's a difference between miles and
nautical miles. The difference is that nautical
miles account for the Earth's curve on the water and in the
air, while miles only account for distance covered on land.
So I think elevation is a factor, but I'm not entirely
sure. You know, This is why I do
social work. There's far fewer numbers.
The great white shark has a wide variety of prey, from seals to
Bony fish like tuna, other sharks, and even giant and
colossal squid. And according to Shark Week,
great whites fight colossal squid often.
And why they're beefing with a colossal squid, I don't know.
But the fact that a 20 foot shark at its largest is fighting
a 46 foot squid is just insane and I support it with my entire
heart. It Whites are also one of the
few sharks that pop their head out of the water to look at
stuff like prey or boats or clouds.
I'm not entirely positive, as the site said they poked their
head up to gaze at objects, which is kind of what everyone
does all the time. We're all just kind of out here
gazing at things. But sharks do it too.
These sharks are a great example of counter shading, as their
lighter Gray body works at many depths to break up their
silhouette from above. But when you're looking below
and looking at their white belly, it's the sunlight that
eats it up and then it breaks up their silhouette as well, so
they're really hard to see. Great whites are one of the most
feared sharks in the world, due in part to movies such as Jaws
using them as the main antagonist.
Although that shark was straight up just a menace and very
unrealistic, but rather fun to watch anyway.
But also the way they eat their prey can invoke a lot of fear
responses. Seeing a possibly 20 foot shark
launch itself 15 feet almost completely out of the water
would be unsettling for many. But when they catch prey such as
dolphins or eat a whale carcass, they aren't really gentle with
it. It's not a simple bite and
leave. They tend to grab and then shake
their head until they get a bit off that they can eat.
White sharks are big fans of whales that have passed as their
blubber is full of calories. These whales will attract many
sharks and marine biologists believe that they use whale
carcasses as a potential mating spot, but it hasn't been
confirmed. Marine biologists are not sure
how mating works for white sharks, as it is first observed
in 1997 and it was only documented in 2020, so about
four years ago, going on five now.
This is also a very small sample size.
Without knowing where mating occurs, it makes it difficult to
thoroughly document how it happens.
Like we know birds dance, frogs crow loudly, alligators chomp
their teeth together, and sharks take a guess.
We don't know now. Globally, white sharks are
listed as vulnerable for conservation status, but in
Europe they're listed as critically endangered as their
numbers have dropped more than in other areas.
Although they are one of the most popular sharks, very little
is known about them as they tend to be very elusive and their
habitat covers a lot of area. They have unsuccessfully been
kept in captivity, but the longest lasting a few months
before it was released. These sharks grow very fast and
the species that have been kept in captivity, few have died
after a few days or weeks. And those that were able to be
kept alive just outgrew their tank really rapidly and they had
to be moved to multiple different tanks, which teams
realized wasn't sustainable and wasn't good for the shark, so
they eventually had to release it.
Marine biologists and researchers are still trying to
figure out the best way to keep them if they were to in the
future. Now, great whites are also
ovoviviperous, which means the eggs hatch internally.
And marine biologists have recorded pups eating their eggs
of their siblings, which sounds insane and rather intense, but
they also pretty much eat everything they can put their
mouth on, except for humans. They tend to leave us alone,
which I do respect and I appreciate very much from them.
But that, of course, is what we have for the great white.
Now we're going to move on to our second shark, which is going
to be the Megamouth. Now, these guys look like an
early Muppet prototype that got the Pinocchio treatment.
You know, like the I'm a real boy.
And then they got released into the world and had a bunch of
babies, and now they're all over the ocean, which is cool.
So these sharks are found in the deep ocean and are rarely seen.
This is a there's usually a big uproar on social media when they
have been seen, which I mean, I feel whenever one shows up, it
should be treated as a holiday that that's just so cool.
They tend to grow to be around 5.4 meters or 18 feet long if
they're female, while the males typically Max out at 4 meters or
13 feet. Now there is very much debate
online as to what color these sharks actually are.
Some people that have seen them say they're black, others say
dark blue, some say Gray and others say brown.
So take your pick. They get to be your favorite
color. For right now, they can be
purple, we'll go with purple. That's fine.
They have a large mouth, as their name would imply.
Their eyes are small and placed towards the top of their head,
and their nose is just above their lip and it has widespread
nostrils. They have rubbery lips that are
uneven, their top lip sticks out more than they're lower, and
they have small teeth that can be visible while they're eating.
They are the smallest of the large filter feeders.
As the basking and whale sharks are much larger, measuring
around 30 to 40 feet. Marine biologists believed that
they were bioluminescent or had luminous photofores.
That's a weird word to say when they were first examined.
Many theories were pitched to explain this glow, but none can
really be confirmed. That was until 2020.
Researchers finally discovered what caused these sharks to
glow, and it's that the inside of their upper lip is very white
and reflects light really well. So they don't glow at all.
They just have really reflective gear on all the time to not get
hit by submarines, which I think is effective and also is a joke.
They don't actually do that. They do have a very white lip
though. It does reflect light.
But many people who have seen mega mile sharks believe that
they are juvenile orcas before they can be properly identified.
Now, I don't really have a clue what a juvenile orca looks like,
but if I were a juvenile orca, it'd be kind of offended because
these dudes are kind of that type of like ugly cute, like an
Opossum. They're rather hideous, but I
love them. Now, I do need to clarify
something. If you're listening in
Australia, I need you to look up an American Opossum.
And Americans, I need you to look up an Australian Opossum
because Australia got the adorable version of this one and
ours got into the leftover math. So it it's fine.
That was a quick tangent. I just need the world to know
that now. The mega mouse shark tends to
spend its day around 120 to 160 meters or 390 to 220 feet deep.
During the night, they spend their time around 12 to 25
meters or 39 to 82 feet, which is rather deep, but a lot more
accessible during the night time than I thought.
But also if you've ever been out on the beach at the night time,
I can just say at night, at night it's it's pitch black.
So it makes sense we haven't seen a whole bunch of them,
especially if they're so deep during the day.
Now the mega mouth also tends to swim around 1.5 to 2.1
kilometers an hour or .81 to 1.13 knots.
So we don't really get mph here, but I think it's because it
wouldn't really register and it's just incredibly slow.
Like go with one mile an hour and then subtract 1 and you're
really close to how fast they go.
They're they're pretty slow. They tend to migrate between
these depths following the flow of plankton through the water
column, which would rise at night and fall during the
daytime. These sharks tend to stay around
tropical waters. Like many sharks, they'll be
found around the equator, Tropic of Capricorn and the Tropic of
Cancer. Although they have not been
observed to go into the Gulf of Mexico, but have been caught
sparsely throughout the tropics. Now this does not mean they're
not in the Gulf of Mexico, it's just we haven't seen them there.
So they've been found in other areas and we just kind of assume
they're they're not there at this point.
Now very little is known about these sharks as they are few and
far between. Since 1976, when the first mega
mouth was spotted, there have been 99 mega mouth sharks caught
or spotted. Very little is known about many
sharks, but there have been thousands of interactions with
whale sharks and the whole tourism industry around them and
we still aren't sure how they reproduce or mate.
So maybe a long while before we know a lot about mega mouths.
Despite the lack of available information, marine biologists
have observed that these sharks are ovoviviparous, which once
again means they have eggs that hatch wall inside the mommy
shark do do do do do do and then they're born after developing
further. Something that is very neat
about these sharks is that researchers had caught 2
individuals off the coast of Baja California and Mexico and
they took adna sample to test for genetic diversity.
Now this often shows if groups are intermingling or if they
stay away from each other. They were able to see that this
there was not genetic diversity meaning of these sharks do in
fact meet and hang out with each other across the ocean, which is
pretty fascinating. And that of course is what we
have for the mega mouth shark. So that brings us to our last
shark of the episode, which is going to be the leopard shark.
Now, First off, I'd like to clarify for our international
listeners once again, Australia, you don't only have different
opossums, you also have different leopard sharks.
So Peter River, I need y'all to listen up real quick.
Evidently Australia and the US switched zebra and leopard shark
names because in the very first episode of Deep Dives with
Sharks. Find it wherever you get your
podcasts. I covered this US zebra shark
known as the leopard shark in Australia, but this episode I'm
covering the US leopard shark that is known as the zebra shark
in Australia. Really glad I didn't cover them
in the same episode. Now for further clarification,
this shark is not the yellow shark with brown spots that you
see in many aquariums. These are the smaller Gray dudes
with brown elongated spots. No, I'm just going to get into
the shark. It's fine.
Now the leopard shark scientific name, I'm going to try to speak
Latin again, have not done this in a while, but this is for
clarification. It's the Triachis semi fasciata
that sounded good. We're going to go with that.
They're also species of hound shark, so that might make it a
little easier to differentiate. These guys are found only around
the West Coast of the US, Canada, and Mexico, but mostly
being found around California. The leopard chart grows to be
about 1.2 to 1.5 meters in length, which is about 3.9 to
4.9 feet now. I thought they were much
smaller. Every picture you see of them
they look absolutely tiny and it always gets me when I realized
they're almost as tall as me as someone who's not 6 feet tall.
So Yep, got a shout out to all the short kings.
Anyway, they are typically a grayish brown color with a
lighter brown spots that have flatter heads with wide set
eyes. They kind of look like they're
bored all the time which is just interesting.
I think that's kind of funny. Their spots appear in bands and
saddles along their back and their head, with smaller
triangular pectoral fins and even smaller pair of cauddle
fins. They form large schooling groups
after they are born, and often with other smooth hounds and
spiny dogfish, which is really cool because I don't you don't
really hear about too many sharks teaming up, which is
neat. These schools tend to be
nomadic, meaning they will travel almost constantly, and
they'll show up in areas for a few hours then disappear about
as quickly as they arrive. While in these traveling
schools, they tend to stay within a certain range and they
will not interact with other schools of sharks that have
formed, thus causing the different sharks in different
areas to have different genetic codes.
How many times can I say different in that sentence?
Probably a few more. This can allow marine biologists
to see the ranges of these schools by catching individuals
and taking a genetic sample to see how far they span.
So unlike the mega mouse shark, where all the species have
similar genetic code, these guys can tell where they're from
because of their genetics, which is kind of neat.
These sharks often follow the tides to hunt and take advantage
of prey caught in shallower waters.
They typically spend time there in depths of about four meters
of 13 feet or less, but have been observed going about as
deep as 91 meters or 299 feet, which is a very specific number
there, specific for the Pacific. Who knew?
But they eat a variety of prey, including crabs, Bony fish such
as anchovies, rockfish, herring and croakers.
But they'll also eat shrimp, clams and fish eggs.
But if they are being opportunistic, they'll also go
for juvenile smooth hounds, shovel nose, guitar fish, bat
rays, algae, and eelgrass. Now the leopard shark is a
suction feeder similar to the zebra shark and the nurse shark.
So I'm kind of seeing the overlap in the names making a
little bit of sense here. But the style of feeding
requires them to open their bucal cavity that creates
powerful suction. Now this will trap their prey,
allowing them to be caught. And it's kind of like a tractor
beam. So, you know, sci-fi, we got
that going to. Similar to the other sharks, the
leopard shark will shed hundreds of teeth in their lifetime.
While leopard shark loses a tooth, it will typically take 9
to 12 days to replace that tooth.
I'm not sure if that's fast or slow or average.
I've not come across really any of the time it takes other
sharks to regrow their teeth. So we'll find out later.
Now, leopard sharks are very timid, especially around humans,
and they tend to flee, then fight.
There's only a single recorded bite that occurred in 1955 when
a diver was having a Nosebleed. They reported that the diver
suffered no injuries, but this is a pretty good reminder and
great example of why you shouldn't go in the water if
you're bleeding. Sharks tend to act erratically
when there's blood in the water. Thankfully, this one didn't do
any damage, but it still probably wasn't the most calming
experience. Now, these sharks are caught
rather frequently. It's both by recreational sport
and commercial fisheries. They're said to have good meat
and can be sold in a variety of ways, but Despite that fact,
they're only listed as Least Concerned under the ICUN.
They often carry toxins if they live close to humans, making
them less of a target because if there's toxins in the meat, they
can't eat it. They are susceptible to sharp
population decline as they take 10 to 12 months to develop pups
and they can give birth to up to 37 pups.
Now this does sound like, well shouldn't they have such high
numbers then? That sounds pretty quick, but
they do take longer than most sharks to mature, especially for
their size. So they're slow growing, meaning
they are easier to catch by their predators.
So they're pretty easy prey sometimes.
But that there is what I had for the leopard shark.
It's going to be it for the episode as well.
I appreciate you all listening. Of course, if you want to ask
any questions or get more updates, you can follow along on
Instagram at deep Dives with sharks.
I don't really use the Twitter anymore, so if you message me or
follow me there, I I'm going to try to check it.
We also have a discord as I mentioned, so check that out.
That's a really good way to interact with everyone.
You can send in any comments questions.
You can also go ask anything in the comments section below.
Lastly, if you learned anything new, be sure to give this a new
rating on Spotify. Five stars there of course, or
Apple as well. And of course, share it with
someone and hopefully they'll learn something too.
Appreciate you guys so much and I can't wait to see you in the
next one.