My name is Jeremy Wade, biologist and extreme fisherman.
I've hunted down freshwater monsters all over the world.
Investigated macabre human deaths and savage attacks.
But it's not often that I come across a fish I've not heard of before,
especially when it could be among the largest freshwater fish I've ever tackled.
I'm heading to the remote north-east corner of Argentina
to catch a monster that somehow got under my radar.
There it is, there it is, there it is!
A creature responsible for horrific injuries.
It will dissolve the flesh.
Even death.
Ripped & Corrected By mstoll
Recently I heard rumours of a giant freshwater fish
that, if true, would be a brand-new species to me.
One that I never knew existed, in a country that I know little about.
I'm in Argentina. I'm on my way to the Paranà River.
It's the second biggest river system in South America after the Amazon.
I know other rivers in South America very well, and the creatures in them,
but this river is very little known in the outside world
and it's also new territory for me.
And, most important, this river harbours a killer.
A little while ago I heard about a child who died
as a result of encountering something in the water.
A 12-year-old girl was playing close to her village
on one of the remote islands set in this huge river.
She had entered the water countless times before
but this time it would be different.
This time there was something waiting in the shallows only yards from the bank.
The attack was brief but ferocious.
She stood no chance against such weaponry.
She died soon after in her mother's arms.
Killed by a freshwater monster.
The evidence from the death points to one suspect.
Shallow water, piercing barb and speed of attack,
all suggest a stingray.
But this is freshwater and I wasn't aware
that there were stingrays in this river.
The Paranà River rises in southern Brazil
and travels through Paraguay into Argentina
before emptying into the Atlantic,
3,000 miles from its source.
The outback town of Bella Vista lies on the banks of this great river,
500 miles from the sea.
Before the arrival of the Spanish,
this corner of Argentina was the land of the Guarani people.
It is now the home of gauchos, farmers and fishermen.
It still has the air of a frontier town here.
This is where I am basing myself on my quest for a leviathan.
I meet up with some fishermen to find out more about the death of the girl
and the creature that I am pitting myself against.
And I discover a lot more than I expected.
They tell me about a small boy who was playing in the river,
only a short distance from his mother, when he was attacked.
There was a commotion in the water, then silence
and the boy's lifeless body floated in the shallows
right where he'd been playing.
What they are describing is a ray
but not one I've ever come across.
They call it chucho de rio, or river dog.
I've caught giant rays before in Thailand,
a massive creature with a tail like a bull whip.
But what they're describing here sounds very different.
And unlike that estuarine monster,
the chucho de rio has made its home 500 miles from the sea.
And what really makes this monster different is that it has killed.
But how? What makes this animal uniquely dangerous?
I visit the regional hospital to meet Dr Gomez,
a surgeon who knows all about stingray wounds.
Wham. OK.
It's not a clean cut. You've got these serrations on the spikes.
So what happens, it makes a mess when it goes in
and then it also rips the flesh when it comes out.
The two children most likely died because the barb
punctured an artery or vital organ, and they quickly bled to death.
But that is not the only cause of death from this massive stingray.
Dr Gomez draws the barb with its backward-facing serrations and venom.
So the mucus that's on the spine,
it doesn't just contain bacteria, there is actually a venom there.
Resulting in deep putrid wounds laced with toxins.
The entire outer skin produces a necrotic venom
which becomes more concentrated around the tail and along the barb,
meaning it is literally cloaked in a venom that destroys tissue.
I head out, knowing that I am on the trail of a creature
with such a fearsome reputation
that the local fishermen refuse to fish for them.
José, my boatman, is an accomplished fisherman,
he has the all-important local knowledge that I always depend on.
His help will be essential if I am to navigate this labyrinth
and find the hidden monster.
This river is a very, very big river.
I was really quite taken aback by the size of it.
But as always, we've got features.
This is a little channel
and we've got a real push of current out here,
but then that current eddies round and there's a nice slack on that side
and exactly the kind of place where any fish would hang out
and the predators hang out feeding on them.
Rays are members of the shark family
but have flattened bodies and wing-like fins.
As yet I've not been able to find any accurate data
about the size of the chucho de rio
but the fishermen here tell me they grow very big.
I want to know how big.
Stingrays patrol the river bottom,
predating on small fish and invertebrates,
which they locate using sensors
that detect the prey's minute electrical field.
My gear is too heavy to cast so I have to adapt.
For bait I'm using armoured catfish,
which I float out underneath a bottle
and release by pulling sharply on the line.
José has a handline attached to the bottle
which he retrieves after the bait has dropped.
Perfecto!
I've not got very much lead on.
It's quite a surge of current here
but the whole thing I was trying to do was to use the current
to take it down then pull it off in the slack beside the current.
That's what will happen to a food item.
If you have to use loads of lead to keep it down,
it's not the place where food will settle.
I've got a nice slack bow in the line
which tells me that bait is in a good place.
This is the same rod that I took to South Africa
where I caught two 500lb bull sharks.
In Thailand I felt the full force of the ray's strength.
It's spinning the boat. It's taking the boat down.
But also the disappointment of losing what, to this day,
could be the biggest fish I've ever had on my line.
I'm not going to let the same thing happen again.
So, armed with what I learnt out there,
I prepare to catch myself a monster.
Oh, here we go, here we go, here we go.
That's...
Something's really after that there.
There's a disturbance at the surface.
And then nothing.
Mmm. I may or may not have bait left.
José thinks that could have been a small ray
maybe having trouble getting the bait in its mouth.
Here we go, here we go.
Something's on that.
No...
That's fairly unusual. When I attempted to set the hook there,
there was nothing there.
But I left the bait in position
and literally within a minute or so, something was back at it,
so it suggests there's lots of fish down there.
I'll just check that I've got the bait.
There we go. The bait has gone.
Something pulled that off.
Whatever is down there seems to be onto me.
It's gone very quiet.
I'm forced to try another location.
That bait lasted about a minute.
Started off as a vicious tapping and then off it went.
One after another, my baits are stolen.
That's not gonna catch anything. Not like that, it isn't.
Something down there is outsmarting me.
Removing the bait even before I can get it to the bottom.
Always there is this conflict between do I just stick it out,
carry on doing what I'm doing, or do I change something?
You have to reach a happy medium with that.
You have to give something a good go but be prepared to change
if it looks like you're doing something wrong.
Something on there, I think.
Oh, it's a piranha.
Wow. Well, what's happened there,
is that the bait's been chopped in half
and I've hooked a piranha in the back.
This is what's been taking my bait, and talk about caught red-handed.
Chunky, chunky piranha.
I've not caught this type of piranha before.
It's very similar to the red belly piranhas in the Amazon.
It's got that orangey throat. Very solid muscular head.
A fairly serious piranha, that.
There are killers of all sizes patrolling this river.
But it is said that the people along its banks
fear stingrays more than any other.
It's a great viewpoint here.
I like to look down on a river. You can see so much more.
What's really apparent here is what looks like the opposite bank at water level,
that's just an island, there's loads of islands here.
I can see a couple of houses dotted around.
And it's very important I go and talk to those people.
They can tell me not just where to go and try to catch fish,
but they might have heard about these incidents that I've heard about.
These people live a nomadic existence.
During the wet season, their ranches are submerged underwater.
They spend months cut off from the outside world.
At a ranch on an island, I talk with a group of gauchos
who explain the dangers of living in such isolation
alongside one of the river's most feared predators.
Yes, there's stingrays here.
I just asked, 'Do you know anybody who's ever been wounded by one? '
'Yes, yes. Not just people but also cows and horses too.'
He said they have known horses to die
as a result of a blood vessel being punctured.
(In Spanish) Infection? Si.
But also they've had other horses die from infection.
He says it's almost as if the horses are crying
because the pain is so bad.
The first place I've stopped, yes, there are rays here
and not just people but also large animals
have actually been killed by these rays.
I'm after a creature that can kill a horse...
yet is virtually unknown to the outside world.
And it is becoming ever-more apparent
the fear the people have around here for these creatures.
Even small ones are shown no mercy.
Not really sure what it's doing here. It's a bit small to have died of old age.
Maybe somebody caught it and threw it up on the bank to die.
I mean, I have seen free-roaming horses here, and, apparently,
they will wound the livestock, so you can understand...
Oh, wait a minute, it is actually... Yeah.
It looks like it's actually been stabbed.
Puncture marks there, so somebody's killed this...
and just... thrown it... on the bank. Discarded it.
Hm.
I know what stingrays are capable of.
But I'm not here to kill.
I want to catch one of these creatures
to try to understand how it attacks before releasing it back into the river.
I can actually feel the movement of my bait
through my finger on the line here.
This line's got a breaking strain of 200lb, but it's very, very fine.
The water's not having much effect on it so I can feel what's happening to the bait
about 40 yards away down there.
Feels a little bit like a spider, in a way.
A spider sitting at the middle of a web with its legs on the lines of the web,
feeling for anything coming into the web.
And so... here I am
waiting for a ray to fall into my trap.
Do you know what?
No, that felt like a piranha.
Nothing there. What?
Look at that.
Yeah. (Sighs)
That's a 150lb line and that's gone through,
but actually I'm not sitting here thinking,
'Oh, no, that was a huge ray that broke the line.'
That's actually been bitten.
It's cut there, there's another half-cut there.
So probably it was a piranha.
That was the width of the piranha's jaws, there.
About an inch or something.
So something's just... is that hungry that it actually has eaten my line.
Hm.
Rays have a finely-tuned sensory system,
which they use to locate prey.
But these sensors could also detect my thick line and hook.
So by changing to finer gear, I hope to fool the ray into taking my bait.
I'm gonna scale down and, er...
That's just a bit finer.
Still very strong. 175lb breaking strain, that.
This is the main line, here.
It's not gonna create a lot of drag when it moves through the water.
The current's not gonna pick it up.
I'm actually quite pleased with that set-up.
I give it one more go, in the hope that as evening falls
the piranhas will stop feeding.
Nothing, nothing.
Very odd.
- Zizzzzz, stop. Doonk. Doonk, doonk, doonk. - Piranhas.
Piranhas are still active, by the look of it.
Cursed by piranhas.
This is the middle of the dry season and the river is at its lowest,
concentrating the fish into smaller and smaller areas.
Hungry and competing for what little food is out there.
Interesting experiment this, just a tiny little slack beside the river.
And it's just full of small fish,
everything in here at this time of year is just so hungry.
The trouble is, if I put a bait in there,
there's so much gonna go for it.
The difficulty is that bait surviving long enough
for the stingray to find it.
It is vital to understand the behaviour
of the other fish in the river besides your quarry,
in order to avoid the other species, like the omnipresent piranha.
To remove these sight-hunters from the equation, I begin fishing at night.
Well, it seems like everything's on the feed at the moment.
Lots of movement in the water.
But now the mosquitoes have joined in.
And so I'm hunting fish, but at the same time,
there's just masses of mosquitoes after my blood.
The only thing that's not on the feed at the moment, it seems, is the stingray.
I set my line, now confident it is past piranha feeding time.
Nothing.
So much for that plan, another one bites the dust.
But I feel as though the noose is tightening. I am closing in.
So I further fine-tune my approach.
I discard the bottle and begin casting,
dropping the bait quickly to the river bottom,
reducing the amount of time it's hanging around in mid-water.
Now will I finally be rid of the curse of the piranhas?
Did you see that?
It feels like a piranha!
But it's too deep for a piranha, I think.
Something has just taken a whole fish bait
and it's coming towards the boat.
Look at that.
So much for piranhas not feeding at night.
These Paranà River piranhas
are among the largest and most ferocious I've ever come across.
And it's so big I can't really get my hand round it.
I've encountered piranhas before and know that in the right conditions,
they are capable of attacking
and devouring the largest prey in seconds.
I don't think I particularly want to fall in here.
Piranhas, big piranhas, but also active at night
shows just how hungry everything is in here.
I fish for hours.
That's really kicking.
I think that's a... Is that a piranha?
Only to pull in one piranha after another, each as big as the last.
That could be time to call it a night, if these guys are active.
But it's hard to give up
when I know the monster stingray must be down there.
I wonder what this is.
Oh! Ooh, look at that.
So this is a surubi, this is a predatory catfish.
This is a small one. These things grow... oops.
They grow over 100lb, so, you know, five or six foot long,
but, I mean, the thing about this fish for me, it's a catfish,
but it's a very athletic, streamlined catfish.
It's a catfish that hunts actively.
It's got quite spiky fins so I have to be careful.
Oh!
Ow. (Bleep)
That's just dug its spine right in the back of my hand.
That went right... Oh, my God.
I've handled these fish loads of times before.
This is the first time I've been stabbed by one of these. It kicked.
And that was its pectoral spine going in the back of my hand.
Although painful, these catfish spines do not have a venom.
This makes me think that I'm going to have to try
and deal with a stingray at night and, you know,
just a moment's loss of concentration with a small catfish and that's the result.
In the Amazon stingrays are known as 'wish you were dead fish'
because of the agonising pain following a stab from the barb.
Even though stingray meat is good to eat
and a large ray could feed many people,
fishermen here refuse to hunt them.
The next morning I meet fellow fisherman Donal Pereira,
who hooked one accidentally.
A momentary lack of concentration
and he felt the full force of a stingray's barb.
So he was fishing for one at the time. He wasn't walking in the water.
He actually had one on the line,
fishing from the bank, and then when he pulled it in,
he lifted it up and said that it just whipped its tail around.
This happened 30 years ago and there is still a very obvious scar there
and he's telling me, and I sort of didn't believe it at first,
so I wanted to hear it again, six or seven years to heal.
It was suppurating for that amount of time.
From just one moment of being stabbed,
six, seven years of a nasty wound taking all that time to heal.
Necrosis can lead to gangrene.
The death of one cell quickly cascades,
spreading to the surrounding cells, killing everything around it.
Following envenomation, the victim suffers severe pain,
vomiting, paralysis, tremors, even heart failure,
and if not treated, death.
As I head back to my boat, I come across a macabre sight.
My first encounter with a chucho de rio.
But this isn't how I imagined I'd first see it.
The guts have been taken out,
no tail - tail's been hacked off on this.
This is a fish I didn't know existed until I came here.
I've known for ages that you get stingrays in freshwater
but this particular species, we're talking about a very short time
that I've known this existed, and here is the evidence in the flesh.
There's no doubt about it, this is a very creepy-looking fish.
The lad in the boat just said, 'What a monstrous animal.'
It is very much like an alien, it doesn't look like any normal fish.
You've got these fine dentacles all over the body, like miniature teeth,
some of them are more enlarged.
As we get to the tail, look at that.
That's starting to get some really serious sharp, lumpy dentacles there.
That's quite apart from the spine you've got on the back,
which is just like this dirty serrated blade.
So, I mean, this animal, it's not just the tail.
This is just like a... very lethally-armed animal.
This stingray is much bulkier than the one I caught in Thailand,
which was flatter, more slight.
It's a good 48-inch wingspan.
The power of this massive body is transmitted to the tail.
Just measuring the size of the tail, as well as the size of the animal.
Four inches across, so that's quite a serious club-like weapon,
never mind the big spike in the end.
One tipped with tissue-destroying venom.
Now to find out the true weight of the chucho de rio.
It's registering just over 200lb there
and it's missing the tail and it's missing all the guts,
and it's been out in the sun dehydrating and bleeding,
so it's something like 225 when this was alive, you know.
I think we can be fairly safe about that.
A genuine river monster.
But if the stories are true,
then there are even bigger fighters out there.
That is what I'm after, to see for myself
the weaponry and the behaviour that makes this creature a killer.
This body of water is vast.
I've been here now for nearly two weeks
and José and I have scoured the area without any results.
So I can't restrict myself to fishing just at night.
I have to get a bait in the water as often as I can.
The river's got a very different character to it today.
There's this wind blowing upstream
and what that does, it's creating these standing waves here,
about 3ft high.
It actually turns it into quite an intimidating place.
Ah. Piranha.
Something's had a bit of that.
Something's moving down there.
Again, I'm forced to scale down my gear
in the hope that I can get the bait past the piranhas
to where the rays lurk.
Just actually changing the leader.
Actually, a ray with its tail flailing around
is a bit like somebody coming at you with that.
And that, well, that could do a lot of damage.
In fact, that is why...
I'll need to be wearing some of these.
These are basically stabproof.
Almost bulletproof, as well.
That'll give me a degree of protection.
It's going to be a knife fight, basically.
Right, I just cast the bait out
and there was instantly something on the bait.
But it just felt like piranhas,
it was like, 'Ra-ra-ra-ra,' kind of thing.
Whereas, what I actually want is something that just goes...
Feels like a piranha.
But the Paranà River is full of surprises.
Ah!
It's a different kind of catfish.
This looks like a new species for me
although it's very similar to one I've caught in the Amazon.
Yeah.
There we go. That's a different fish.
And again, it's just another fish that is going to polish off my bait.
You know, it really is a problem, actually,
just having a bait down there that's gonna survive long enough
for the stingray, which is pretty much the top predator,
to come along and find it.
Big strikes often come when you least expect them.
So I have to stay prepared for when my rod bends double
with the weight of a 250lb monster.
There we go! That's a fish on!
This is by far the biggest fish yet to take my bait.
It's to the surface! There it is!
There it is, there it is!
That's a stingray.
It's off the bottom.
There's trees down here!
Although this is only a juvenile, it is still armed with a deadly barb
and tissue-destroying venom.
It's a long way off yet but...
I don't want to bring this into the boat.
So I ask José to head for the nearest beach.
I put on knife-proof Kevlar gloves to protect me against the barb.
I'll just pull it up.
As soon as it's out of the water, its tail is aiming for me.
I notice that this ray is a heavier build than other rays I've caught.
And the tail much shorter, more like a dagger than a whip.
See if I can get a look at that.
The ray's tail is coated with toxic venom.
Just gonna see if I can get any mucus off here.
General fish slime.
That's just sort of slime, that's mucus.
Living in there, you've got a cocktail of bacteria.
I'm actually thinking about what those cowboys were saying.
They've had horses die from fatal bleeding
but also from the infection when they've stepped on a ray.
Ooh!
That's actually one heavy beast.
And that's the... I'm just feeling the weight of this animal now.
And this is a small one. I'm just thinking, a weapon like that
with 400, 500, maybe 600lb behind it,
it's like somebody coming at you with a medieval mace, in a way.
It's like a club with a nail in it.
Anyway, let's get it back.
Easing it into slightly deeper water.
Now, just looking at the pattern of this, and it does
just completely disappear into the background.
It really does bring home how dangerous potentially these things are,
when you just see how they're just almost invisible in the water.
That was actually a small one.
What I want to see now is a big one of those but, er...
if I do get one, I think I'm really gonna have my hands full.
I've been trawling this river now for ten days straight
and I'm beginning to think that the only giant ray I'm going to see
is the one hanging on the river bank.
So I'm fishing all the hours I can to maximise my chances.
As yet another day turns to dusk, I have to be patient.
Then I get a take that seems different from the others so far.
Look at that.
So this is a dorado.
Whoa - Hey!
It's got some teeth, there. Serious predator.
And one of many predators in the water here
and this is just one of the things beating the stingrays to the bait.
This is the game fish that most anglers come here to catch.
I'm just putting that back. That's not what I want.
I want this sluggish thing that skulks on the bottom.
Most of my brother anglers would be the other way round.
José and I fish all over the river.
This is a mandube catfish.
This is about 1/200th of the weight of the fish that I was after.
Mystery bait remover.
It's another night with no stingrays.
They're proving elusive.
I've caught everything except what I came for.
Now I try something that I wouldn't normally do.
I've got a second rod out.
A lot of people in the town are giving me advice of what I need to be doing
and one of the things that keeps cropping up is,
you haven't got enough lines in the water.
I don't totally hold with that.
I don't necessarily believe that two rods gives you double the chance
but it all comes down to one bait being in the right place.
Even though I've given in to using two rods,
only one is really strong enough to land a monster.
If the lighter rod happens to hook a fish,
I could be out-gunned.
That's a good fish, that's a good-sized fish.
This feels like a ray.
Just my luck. The fish took the bait on the lighter outfit,
which isn't really up to the job.
This is bigger than the last one, for sure.
In Thailand, a giant ray snapped a rod that wasn't right for the job,
something I really don't want to happen again.
On the limit of what this gear can hold, really.
Yeah, that's moving, that's moving.
Plus, it looks like the river bottom is littered with dead trees.
One snag and this fish is gone.
I'm off a very snaggy island at the moment.
If we can just slowly, slowly go down in the current,
then we're clear of that and we're then adjacent to a beach.
And also the current's slack there.
We can just very slowly coax it into shallow, slack water.
Because the ray took the bait on the weaker rod,
I have limited pulling power, so I'm in for the long haul.
It's now been on well over an hour.
At last I've got past the piranhas, catfish and dorado,
but the creature on the end of my line might be twice my size
and it isn't going to give itself up easily.
Two hours and ten minutes now.
This is becoming a war of attrition.
Which will crack first: The ray, the rod or me?
Ooh, yes! Yes, yes, yes.
After 11 gruelling days of fishing,
I've hooked what could be the biggest totally freshwater river monster
I've ever had on my line.
It feels like it has come unstuck from the bottom a couple of times.
But most of the time it's just a dead weight.
Every now and again, there's a slight movement. It rises...
and then it sort of sticks down again.
Rays stick themselves to the bottom.
Prying them off is like pulling the plug out of the river.
This just feels like a dead weight, a dead weight.
That could be in a tree, it could be in a tree.
It's using all its bulk and the flow of the river to defeat me.
What I'm going to do is take the boat upstream a little bit
and I'm just going to apply some pressure just from the other side,
because if it's in a snag, possibly,
if I can just get a different angle on it...
José has to manoeuvre very precisely in the strong current.
That's a tail hitting the line, a tail hitting the line!
With a fish like this, I'm not in control.
All I can do is react.
Three hours.
This is my longest battle ever,
beating even the South African bull shark
that took two hours and 45 minutes.
My back and arms are now burning.
That is fish, I think, that is fish, that is fish, that is fish moving.
It's back, my manoeuvre worked.
A bit of tactics. Nothing was happening, nothing, nothing, nothing,
and I think it might have just hooked the line round a branch.
So we just changed the angle of the pull slightly.
Look at that, there it goes, that's good, that's good.
I want to get it to the beach where I can handle it safely.
But that means coaxing it 200 yards further downstream.
We've got it literally just 10-15 feet from the bank.
As the creature tires I have it exactly where I want it.
There it is! There it is, there it is, there it is!
Finally, after perhaps the most punishing battle I have ever had,
I land one of the biggest, strongest
and most alien freshwater fish I've ever seen.
The thing I really want to do, though,
is get a closer look at the tail. Obviously, not too close.
And to think this is a fish that until recently
I didn't even know existed.
The chucho de rio is unlike any other ray I've come across.
OK, 5... nearly 53 inches.
Which would make it easily 250lb.
But what really makes this species stand out
is that it is a killer with a weapon as brutal as a medieval mace.
Like a club fortified with rusty nails,
which it drives in with its massive bulk.
I might have to just kneel on top of the animal.
OK.
That's what I wanted to look at.
The dead animal I saw had its tail chopped off.
This one has its sting intact. Actually got two stings on there.
And also, by the look of it,
this can come a long way on either side, it's also very flexible.
So I wouldn't want to get anywhere near this.
Time to put this back in the water.
My arms are just aching so much. I've been fishing solid for 11 days.
If this feels anything like I do, it's very tired.
What I'm about to do is very significant
because I always like to return fish alive
but this is a fish where, you know, the locals don't give it any quarter.
This stingray has evolved to survive in totally fresh water.
In fact, it is now thought to be incapable of living in the sea.
Just bent over it, I'm just not seeing the shape of the fish at all.
I've just got this huge broad back with this amazing pattern on it.
As fish go it has to be one of the strangest fish there is,
and in a river, as well, the size of this thing.
I've been fishing the world's rivers now for four decades.
But landing a monster like this makes me wonder what else is out there,
still to discover.
Ripped & Corrected By mstoll