River Monsters (2009) s02e02 Episode Script
Death Ray
I'm Jeremy Wade, biologist and extreme angler.
From the depths of the Amazon to the suburbs of Berlin, I've been busy, tracking down the world's most frightening freshwater fish and uncovering the truth about their evil reputations.
It's taking line! That's taking line! I've tangled with man-eating catfish This is the one that goes after people, as well.
swum with piranhas and grappled with ferocious gar.
Agh! My next assignment is a beast of terrifying power.
It's spinning the boat.
It's taking the boat down.
Some people say this is the world's biggest freshwater fish.
If my line jams, it could pull me in.
This is a monster that can stab you with an eight-inch bayonet.
Its flesh-dissolving venom has no known antidote.
Just catching this fish will test me to the limit.
But my aim isn't simply to measure one of these giants.
I also want to know where it lives and how dangerous it really is.
- I've a feeling this could be - Agh! my toughest challenge yet.
- Here it comes! Here it comes! I think we're going to need a bigger boat! In just the past few years, a strange and possibly deadly creature has come out of the shadows.
I've read dramatic accounts of epic, six-hour battles and heard that this predator can inflict horrendous wounds.
Some people are even claiming that this little-known beast is the world's biggest freshwater fish.
The name of this monster is Himantura chaophraya, the giant freshwater stingray.
Shaped like a UFO, this Southeast Asian giant is said to grow to 16ft long and 7ft across.
Some sources put its weight at over 1,300lbs.
Even this basic information is very hard to verify.
It all sounds incredibly impressive, but how much of this stuff can I really believe? It seems that no-one knows how big this thing actually grows or why.
I've encountered river stingrays before, a thousand miles up the Amazon.
Here, they're known as "wish you were dead" fish, because of their agonisingly painful sting.
But these stingrays are relatively small.
The thought of a 16-footer sends a real shiver down my spine.
These are some examples of the wounds caused by marine stingrays.
Typically, what you're talking about is a very deep puncture wound, normally to the foot or the lower leg but sometimes higher up.
And the people generally talk about this as being extremely painful.
As well as the actual immediate wound, you have this very long-lasting effect of tissue necrosis.
It's just a very painful, messy wound.
Here's one from New Zealand.
You can see here that the barbs are actually still embedded in the leg.
The bit you can see is probably about five, maybe six inches long.
This is in the upper leg.
This person was very lucky.
If that had been a little bit further round, that could have punctured the femoral artery.
That could have been a fatal wound.
That could have killed him.
Note to self.
"Don't get stung.
" This is the barb from a stingray, actually quite a small one.
But you get the general idea.
The barb sits on top of the tail and it whips it over its back, a bit like a scorpion, or it can also whip it round to either side.
And looking at this, you can just see just how wickedly sharp that point is.
The second thing is you've got these grooves running underneath.
That is for delivering the venom from the gland at the base here, but also for making it a more efficient stabbing weapon.
You'll see exactly the same thing on a bayonet or a combat knife.
And the third thing, looking closely at this, you see these serrations along the edge here, and it works on the same principle as an arrowhead.
It goes in very cleanly but, you know, it's going to make a real mess when you pull it out.
Imagine being stabbed by a large steak knife, only this one's smeared with poison and it really shreds your flesh when it comes out.
Yep.
I've heard that the giant freshwater stingray has a barb that is eight inches long, which is a really sobering thought.
I'm quite curious to have a look at one of those, hopefully not too close.
It's not something I want to bring back as a souvenir in my leg.
My quest for the giant freshwater stingray takes me to Southeast Asia.
First, to Thailand's capital, Bangkok.
Surprisingly, this huge and potentially lethal monster lives right under our noses.
Normally, when looking for underwater monsters, you're thinking hundreds of miles upriver, in remote wilderness, but not this time.
I'm literally taking a short cab ride from the airport and I'm slap-bang in the middle of Bangkok and just a few miles away from the sea.
Even more incredibly, scientists only discovered the giant freshwater stingray a mere 20 years ago.
Its species name, chaophraya, comes from this very river, running through the heart of Bangkok.
And yet this monster in our midst is still cloaked in mystery.
I want to find out how big it really gets.
I also want to know how far this animal travels inland.
In most people's eyes, stingrays are sea creatures, not river fish.
Barely an hour's drive from the capital, I track down a story that puts me on edge and reminds me that the venom of this creature has no known antidote.
Four months ago, local fisherman Pun Sang was surprised to hook one of these rarely-seen giants.
For people here, such a huge fish is a potentially lucrative catch.
(Speaks Thai) The stingray came to the side of the river and then wouldn't come any further.
It basically got buried in the mud.
So what he had to do was get in the water, which was about chest-deep, and then completely go underwater with a rope, feed the rope through the spiracles, the water intake of the stingray, knot the rope.
He'd managed to pull it off the bottom.
It was actually as it rose in the water that he then felt this pain.
Argh! The wound was actually just numb to start with.
And then just this incredible pain.
In fact, so painful that he collapsed from the intensity of the pain and had to crawl the remaining distance to the house.
This was not going to go away on its own.
It did need urgent medical treatment.
As he races for help, Pun Sang continues to bleed heavily and almost passes out with the pain.
With no antidote available, his chances of survival are anyone's guess.
By the time he arrives for treatment, his condition is deteriorating fast.
- What happens at the medical centre? - (Speaks Thai) His heart rate spikes alarmingly.
Despite anaesthetic, he remains doubled up in agony.
The wound, in fact, is no more than a glancing blow.
And yet the pain proved so intense that Pun Sang is unable to work for the next four weeks.
He still has the very barb that impaled him.
Can I have a look at that? Right.
Well, seeing that really does concentrate the mind.
An absolutely vicious point on that and these horrible barbs down the side.
And I think you know, this is a fish I've got to really treat with some respect.
Evidently, even a quick jab from this fish can land you in serious trouble.
Whatever it contains, the venom seems every bit as potent as in marine stingrays.
OK, so that actually went in about getting on for three inches, there, but it was at an oblique angle, and So although he probably doesn't feel lucky to have had this experience, if that had gone in straight and punctured the femoral artery, that could have killed him.
Tragically, Steve Irwin, the Crocodile Hunter, was not so lucky.
He was struck clean through the heart and died.
While this freak accident happened way out at sea, the chilling fact about the stingray I'm looking for is that it swims up rivers, into some of the most densely populated parts of Southeast Asia.
And it's in these crowded waterways that I'm about to try and meet this monster face-to-face.
I head to a town called Samut Songkhram, 50 miles west of Bangkok and just a few miles inland.
This tidal stretch of river harbours some of the largest freshwater stingrays ever caught.
This fish, the giant stingray, was only described by scientists just 20 years ago, but, presumably, the people on these rivers have known about it probably for centuries.
The problem the scientists had was getting their hands on enough specimens to study.
What this means is either it's a very rare animal or it's just very, very hard to get one out of the river.
To try and catch one of these elusive giants, I'm teaming up with an experienced fishing crew, led by stingray enthusiast Boy.
Live bait is essential.
Its muscle movements will give off the electrical signals that stingrays use to detect their prey.
These animals are active hunters, prowling over the riverbed in search of a meal.
Their faces are packed with sophisticated sensors that penetrate the mud and murk.
Potentially eight times my size, this fish is in a different league from anything I've tackled before.
It calls for the heaviest gear.
I'm using ultra-strong braided line, with 30 yards of thick nylon monofilament at the business end.
To take some of the strain, I'll be wearing a harness.
Good news for my arms, but if the line digs in and jams, I could be pulled in.
Normally, the fish can't take line and the line will break, but when you're using a 160lb line, that line isn't going to break.
I'm going to go over the side.
After Pun Sang's account, I'm anxious to avoid this nightmare scenario.
If that's dug in, for some reason, I've got to have Plan B.
I'm going to be strapped to that, have a harness locked into that.
So I've got a knife.
If I'm going over the edge, the knife comes out and just cut that line.
The fish can go.
It's better than drowning.
With everything prepped, we head for the chosen spot.
A deep pocket in the riverbed they call "Area 51", because, as they say round here, it's crawling with aliens.
My battle boat is rigged with four big-game rods, including my own marlin-class outfit that I've brought for the occasion.
If a line goes, I'm ready to hunker down, strap in and lock horns.
To improve the odds, Boy's put out a dozen or so extra lines, tied to floats.
This isn't regarded as true sport fishing, but my mission here isn't to beat my chest or win prizes.
I simply want to see one of these incredible animals in the flesh.
And, within minutes, there's something big mauling our baits.
It didn't run off with the bait but there's been a stingray on that.
Something has come along and crushed that there, but, then, instead of taking the bait, it's spat it out.
Stingrays have crushing mouth parts that leave an unmistakable imprint.
Disappointing in one sense, but also good news.
I'm in the right place.
They are down there.
The next bite's a clean take and we are game on.
As I race to clip in, something powerful rips out several feet of line, then decides to tow us upriver.
It's spinning the boat.
It's taking the boat down.
I think we're going to need a bigger boat! OK.
Right.
Ah! Oh, yeah, that is Oh, look at that rod! That rod is now springing back slowly.
This line shouldn't go.
The rod's a bit of an unknown quantity.
Ah! It's my own marlin-class outfit taking the strain.
I just have visions of this rod suddenly shattering and getting a face full of fibreglass and carbon fibre.
That's pulling down.
That's pulling down.
There is quite a real possibility of this thing pulling me in.
I feel like I'm trying to pull the plug out of the river.
All I can do is dig in and keep the pressure on.
After 30 exhausting minutes, I haven't gained an inch.
Ah! Ah! This isn't like any fishing I've ever experienced and I start to wonder if I can cope.
Most fish, it's all over in five, 10 minutes, half an hour at the extreme.
You know, this In freshwater, something like this is just It's just unheard of.
With neither of us willing to give in, it becomes a war of attrition.
Give or take the odd foot of line, we're in total deadlock.
Be careful.
I've just been told it's one hour five minutes, so far.
We're into about round eight now.
Oh, look at that! It's taking line.
That is taking line fast.
This thing does not like being bullied.
I decided I'd show it who's boss and the fish is saying, "No, no.
You're not the boss.
" Ah! Oh! That's about half an hour's worth of work has just gone.
I've just gained about 3ft of line and it's just taken that.
But, sometimes, when it does that, the fish then takes a bit of a breather and I can maybe capitalise.
For another 40 minutes, we slug it out in a gruelling tug of war.
Right, I've got the initiative.
Whoa! Ah! Ah! Then, after almost two hours, a breakthrough.
I think it's come off the bottom.
There was a sudden Argh! A sudden sort of break of suction.
It does feel like it is actually Yeah, that's definitely coming my way a lot faster than it has done at any time until now.
My arms are cramping up and I'm close to breaking point, but I've finally got the measure of this gigantic fish.
It's about a metre and a half below the surface.
Here it comes! I'm just seconds away from seeing what must surely be one of the world's greatest river monsters.
Oh! Right, look at that.
The rod went.
The rod went.
I actually saw the fish.
We nearly, nearly had it in the net, but An almighty bang.
Oh! My gear was built to deal with sharks and marlin.
Whatever broke this rod could have weighed as much as 700lbs.
I thought it was my shoulder going for a minute, but it was the rod.
- Too long.
- The rod's too long.
Yeah.
Oh, dear.
That was so close.
The fish nearly came in.
We saw it.
After two hours, it was off the bottom.
We were trying to get the net round it.
The rod went and the fish escaped.
It wasn't quite in the net.
And to make matters worse, the fight has left me with a torn bicep.
All that suffering I saw the fish and it's Oh! All that for nothing.
All that.
Oh! It's score one to the stingray.
But my close encounter with this giant has got me wondering.
Why does this creature grow so huge? As this photograph graphically shows, marine stingrays are vulnerable to attack by sharks.
But what could possibly threaten a river stingray? Perhaps it's no coincidence that the rivers here are also home to another gigantic fish.
Growing up to nine feet long and weighing over 600lb, the Mekong giant catfish is a Class A monster.
Conceivably, the stingray's immense size could be a defence strategy.
To get a close-up look at a giant Mekong, I've come to a stocked fishing lake.
These animals are all but extinct in the wild.
This is a strong fish! Got the line against the This one's giving me the run-around.
A huge tail.
A huge tail on that.
But it's probably just a small one.
A very powerful sort of throbbing fight.
You can almost feel the beats of the tail.
That's a Mekong catfish.
My catch is only one-tenth the size of what they can reach.
Nonetheless, I can see it's no ordinary catfish.
Being a catfish, it's got no scales, but what's interesting, as well, although it's a catfish, it hasn't got feelers, barbels.
And the other thing that's interesting here is there's no teeth in there.
There's not even anything approaching one of these raspy pads in there.
Although this does grow very big and well over 600lb, it's not a predator.
This thing is a vegetarian.
It's a gentle giant.
If I'm looking down from here, I can't see any eyes.
The eyes are on the underside of the head, very close to the corner of the mouth.
That's something that just points to it being a bottom feeder, rooting around vegetable matter on the bottom.
So this gummy oddball isn't a killer, which leaves me still wondering why the stingrays here have evolved into such giants.
I've yet to see a chaophraya stingray.
Dead or alive.
But with Thailand's biggest fish market just down the road, I'm back on the hunt.
This is a vast clearing house for everything that comes out of the sea for hundreds of miles around.
Stingrays first evolved in the oceans.
And it could be that the giant freshwater stingray occurs in the sea, as well as rivers.
So we have got rays here.
I'm finding some rays.
That's not the one I'm after.
This is an eagle ray of sorts.
Yet another species of ray.
These are all marine species, but this is bringing home there is a huge diversity of ray species, lots of variations on the theme.
Stingrays are clearly one of nature's more successful designs, but their origins, some 200 million years ago, may come as a surprise.
A quick lesson in evolution here.
Here's a shark.
That is the classic shark mouth, the classic shark teeth, the shark tail.
Come to this fish here.
Shark tail.
Shark dorsal fin.
But something very different going on at the front end.
It's flattening, becoming squashed.
Let's flip it over.
And suddenly we've got a very different type of mouth.
Crushing plates but very different.
Gills on the bottom of the body.
Come to this fish here.
And here we have the same mouth, the same gills.
Flip it over.
There we have it.
A ray is basically a flattened shark, with this long tail.
This flattened body plan, with the eyes and water intakes on top, is an adaptation for life on the ocean floor.
Whatever its origins, the monster I'm after continues to elude me.
After three hours of trawling, I haven't found a single specimen.
I head to the freshwater stalls, where the fish are still pouring in.
If there are no giant stingrays coming out of the sea, then perhaps I'll find one here.
Any chaophraya here? (Speaks Thai) No? So no stingray here.
I don't know how many thousands of fish I must have seen here.
Thais really do love their fish.
They eat pretty well anything that swims.
But the freshwater ray is not here.
This could be because it's rare.
It could be because it's just hard to get out of the river.
Maybe there is another reason I don't know of, but I haven't found one.
To learn more about this elusive monster, I'm meeting a scientist who has more hands-on experience of this stingray than anyone in the world.
Dr Ning, from Chulalongkorn University in Bangkok, is one of the few people trying to study this animal.
Our first task is to collect some water from the bottom of the river, some 30 feet down.
One thing I want to know is whether this ray is a true river fish, living in pure fresh water.
That's on the bottom.
We're only six or seven miles from the sea here, so I'd expect the river to be quite salty.
In my mind, this puts a question mark over claims that the giant stingray is a true freshwater fish.
Now then, this is the moment of truth.
If this were pure seawater, the salt meter would give me a reading of 30, with brackish water at around 15.
So that is right on zero, which I'm quite surprised by.
It's very obviously tidal here.
I had my doubts about whether this thing is a truly freshwater animal.
I think that is something that still requires a bit of unpacking, perhaps, but it is certainly capable of living in water that it is absolutely fresh.
There's no trace of seawater at this point, at the moment.
In theory, they could be even further up these rivers.
While I'm here, I also want to find out more about the stingray's lair.
This stretch of water is less than half a mile from where I hooked the monster that broke my rod.
Ugh! Look at that.
That's what's on the bottom here.
Thick mud is going to give my quarry a big advantage.
They are going to get a very good seal and very good suction.
I now understand why I had such a battle to pull up this animal.
Imagine that's the stingray.
That weighs nothing.
I can lift that easily.
And Just getting a little bit under the mud.
There we go.
And I can lift it up.
Look at that.
- Argh! - (Laughs) So, if that stingray gets the edges of its wings under the mud, I'm not just lifting the stingray but the whole bottom of the river.
One of the things I want to find out about this fish is how heavy it gets.
For a small fish, you put it in a bag and weigh it.
For something the size of these, we've had to come up with something special.
Back at Area 51, our lines are set.
And I'm hoping my luck's about to change.
As we wait for a bite, Boy tells me an unnerving story.
heart here.
Made by heart go bump-bump-bump.
Sweat.
- And that's the scar of it there? - Yeah.
Just here.
I've just been asking Boy about stingray wounds, this kind of thing.
And he told me a story about how a small one just scratched him on the finger and he thought that's going to be fine.
15 minutes later, the entire left side of his body's gone numb.
The heart is pounding away.
He was thinking this could be like a snake bite, this could be fatal.
After three hours, it passed.
And I'm just thinking, you've just got to be so careful when handling these things.
With plenty of floats out, it's not long before I'm back in the ring.
This time, I've learnt my lesson and switched to a shorter rod.
It's my arm that worries me.
I'm not sure it'll take another 12 rounds.
To my relief, it's barely 20 minutes before this one starts to surface.
The fish is coming up! The fish is coming up! OK.
OK.
Are you ready, boys? So we've got the fish here in the net.
I've finally caught one, my first chaophraya stingray.
I keep well clear, though.
Until its sting is strapped up, this fish is still a loaded gun.
So this is just binding the barb, which sits in a bit of a groove.
That is binding the barb to the tail.
Once it's disarmed, we head for the bank.
Most of the body of the fish is in the water.
I haven't really properly seen this fish.
I'm really looking forward now to getting it in and having a proper look at this animal.
The pink tinge on the belly makes me think of the rash that divers sometimes get when they come up from depth.
This fish has surfaced from 30 feet down, enough to give it a mild case of the bends, so it's vital we release it soon.
This species is said to top 1,300lb, yet, as I now discover, this is only half the story.
We've got a male.
This one's a male.
The entire team is on hand to help measure and weigh the fish.
So this one's about four and a half foot across.
It's not particularly big as they go, but it is very big for a male.
Its sex explains why this one came up so fast.
Astonishingly, females can be up to eight times bigger than this full-grown male.
We've weighed it accurately, which is quite a hard thing to do.
175lb.
Around 80kg.
For sheer weight, this is one of the largest fish I've ever caught.
And yet, incredible as it sounds, it's a mere minnow.
It's been out of the water long enough now.
Definitely time to get it back in the water.
The males may be relatively small, but they're still armed with a potentially lethal sting.
Before we turn him loose, I go in for a closer look.
This is the business end.
This is why it's called a stingray.
This sharp, pointed poisonous barb on the tail end.
And it can throw this not only over its head, like a scorpion, it can throw it side to side, so that is the weaponry seen up close.
A very impressive bit of weaponry it is, too.
OK.
This is an animal that completely warps your normal sense of scale.
Despite catching a good-sized male, I know that my quest is far from over.
Since it was first scientifically described, there have been occasional reports of large chaophraya stingrays from far inland.
I'm leaving the tidal waterways around Bangkok and heading up country.
Could this be where I'll finally find my monster? I travel 150 miles north, following the Chao Phraya River upstream to a town called Nakhon Sawan.
But it's late May and the rains are starting to break.
As I begin to fish, the weather takes a turn for the worse.
(Rumble of thunder) For three hours, it pours without let-up.
All I catch is a dose of the monsoon blues.
(Rumble of thunder) At least someone's having some luck.
Then I meet a man with an amazing tale.
This was what, just here in Nakhon Sawan? (Speaks Thai) This is interesting.
This is a recent capture.
Only a few months ago.
I'm imagining that that wasn't easy to get out.
How long to get this out of the river? (Speaks Thai) Clearly, a very big fish, this.
Apparently 320kg, which converts to something like 700lbs, a seriously large fish.
The story is it took 10 people, in two boats, four hours to get it in and it actually dragged the boat well over a mile during that time, so I think a bit of an epic battle and a big fish.
Looking at the man's tackle, I'm amazed he got it in at all.
Ah, we've got a video clip someone took.
Obviously big local news.
There's people all around.
I'm no stranger to fishermen's yarns, but the figure of around 700lbs does ring true.
This fish was cut up and weighed accurately for market.
It seems they only kept one piece of it.
Oh, right.
- Is this from the same fish? - Yeah, same fish.
Ooh.
Right.
OK.
Even with its tip broken off, this barb is by far the biggest I've seen.
If there are giant stingrays here, then how much further upriver do they go? I'm starting to wonder.
Could these creatures have penetrated deep into the river systems, just like their distant Amazon cousins? Getting on for 3,000 miles long, the mighty Mekong is Southeast Asia's greatest river.
Until just the last 150 years, its upper reaches remained largely cut off from the outside world.
Even today, it still feels like a land of secrets.
If anyone can help me unlock them, it's the fishermen who make their living along its banks.
I'm now 1,000 miles upriver and I wonder if anyone here will know about the creature I'm looking for.
I wonder if you, fishing here, see any chaophraya? (Speaks Thai) The big-sized chaophraya or these were small fish? Any really big ones? (Speaks Thai) What happened there was that the stingray got wrapped up in the net.
This big one just broke its way through.
It sounds promising.
But I want a positive ID.
Will they recognise the fish from Nakhon Sawan? Same fish? (Speaks Thai) Yeah.
(Speaks Thai) So the same fish as here? (Man speaks Thai) Right.
This is very interesting.
I've shown the picture of the ray that was caught at Nakhon Sawan.
Not only is it the same species, it was also about the same size.
This was a big animal here.
That's a very encouraging bit of information.
It does bode well.
I'm going to be putting a bait in water where these things are.
Do the fishermen here try to catch chaophraya or is it always an accident? Do you Is it a good fish to eat? Do people eat it? (Men speak Thai) Ah.
OK.
OK.
So the stingray will come after the small fish in the net.
It's a nuisance species.
They try and get the fish that are in your net.
They get wrapped up themselves.
Then you've got to take them out and be very careful of the sting.
If you get a big one, they're actually going to rip your net apart.
So they don't fish for them.
It's a nuisance fish, they call it.
I head further upriver into even more remote country.
But the Mekong seems unwilling to give up its secrets.
Am I looking in the wrong place, I wonder, or fishing in the wrong season? My right arm still aches from the two-hour battle I fought and my exercise routine brings little relief.
Just curious looks.
Undeterred, I travel back downriver.
With a confirmed eyewitness account, I'm eager to take a look for myself.
I'm at a place called Nong Khai, right on the border with Laos.
25 years ago, I was actually in this very same bit of river.
A little bit upstream.
And I was arrested by the police on suspicion of spying.
And that cut short my entire trip.
End of fishing.
End of everything.
They locked me up for the night and confiscated all my photos.
This time round, I'm using sophisticated sonar equipment to scan the riverbed.
I'm looking down into the water.
I've got the sonar, 20 foot of water.
I'm trying to get a mental picture of the underwater geography, as my first step in looking for the stingrays.
I've actually got fish symbols straightaway, but they're middle of the water, unlikely to be stingrays.
Although, if there is something close to the bottom, it could be a ray.
They don't spend all the time just stuck right down.
Sometimes, they do actually rise off, maybe three or four feet and glide away.
I'm convinced there are giant stingrays down here, but before I can unpack my rod, there's a nasty surprise.
(Whoop of siren) One problem about here, it's the border between Thailand and Laos.
I might have possibly strayed over the border.
I'm just going to carry on acting normal.
I suppose I have got some fairly hi-tech gear on the boat.
I'm spying on the bottom of the river.
(Whoop of siren) OK.
OK.
Go in? OK.
OK.
They probably don't see that many foreigners on the river here.
I've been waved into the side.
I've been waved into the side.
They are still very, very keen on keeping an eye on people who do things by this border.
The border area is just very sensitive.
That's another difficulty in trying to find this stingray here.
The political situation.
I avoid jail, at least.
But I've no choice but to cut short my mission and head back south.
I'm starting to wonder if I'll ever see this elusive monster.
With one last throw of the dice, I return to Area 51.
My hopes of actually seeing the monster I've come to find seem to be drifting away.
To catch this seemingly rare and almost legendary beast, perhaps I need a little help from the gods.
I'm back at Samut Songkhram, where I've already caught a full-grown male and come painfully close to landing a truly massive female.
Just get the rods on first.
This time, the stakes are even higher.
A team of scientists has arrived from Chulalongkorn University in Bangkok.
They're counting on me to provide a live stingray for their research.
So little is known about this animal that every catch offers a rare chance to learn more.
The scientists will settle for any stingray I can catch, but, for me, this is all about seeing a true giant.
To hell with my sore arm, I'm just hoping we've hooked a big female.
I haven't come this far to miss out.
I get the illusion now that I'm actually bringing the fish to me.
What's actually happening is I'm taking the boat to the fish.
The fish isn't actually going anywhere at the moment.
What do you think? Is it a fairly good fish? Oh, it's just actually come off the bottom! It's a worrying sign.
Any monster worth its salt isn't going to give up so quickly.
But then the stingray sinks back down, switches gear and takes off upriver.
Oh! The drag on this reel is a little bit like the handbrake on a car and I've got that almost fully on.
The fish is basically just taking that line.
As I watch, at the moment, it's just going out one inch, two inches, three inches.
After half an hour, my opponent stops for a breather.
And I do the same.
Then we're back for Round Two and it's looking like a big fish.
Seven of us, on two boats, are dragged half a mile - against the tide.
Right.
It might surface! It might surface over there.
Now I've got the fish on the ropes, for the first time it feels like I'm driving the bus.
Under the boat.
I don't want to be lifting it while it's under the boat.
I think it's coming this way again.
It's just squashing my fingers! It's gone this way.
See the water there? I haven't seen the fish yet.
It is near the surface.
I've just seen the lead.
It's up in the water.
I think we've got it.
Back of the net, and this one looks pretty big, with an impressive 10-inch sting.
Head of the science team, Dr Ning first secures the barb.
(Speaks Thai) She's asked me to help her collect some venom before we release the fish.
It takes six people to heave this huge animal onto its front, into a position where we can measure it.
180cm to the base of the tail.
Going for the wingspan.
1.
91 metres.
Nearly two metres across.
1.
91.
At around six feet across, and roughly 400lbs, this female stingray is by far the largest river fish I've ever seen.
Little did I realise she was about to produce the mother of all surprises.
So we've just got the fish in to where the scientific team is.
And, literally, as we sort of pulled it into the net, it's actually given birth to two live young.
Dr Ning uses ultrasound to see if there are any more babies still inside.
This is the first time scientists have been able to collect data from the fully-formed pups of these stingrays.
Here, here.
On the ultrasound, the dark line is the cavity and there is a lighter shape inside it.
Apparently, that is the baby stingray still inside.
For me, this fish is a real first.
And not just for its size.
I thought I had one fish on the end.
It looks like I've got one, two, three, and another one inside.
Four fish, one hook.
Like many sharks, stingrays give birth to live young.
When they emerged, these babies had what looked like a small cap on their stings, presumably to prevent internal injury to the mother.
However, these safety catches soon drop off.
Within minutes, these twins are armed and ready to defend themselves.
It has been known for these fish to eject young when they are caught and if they are not well developed, there's a worry they won't survive.
The great thing about these two fish is they are pretty well fully developed.
They might be being born a little bit early, but I think they will survive in this river.
With that two-inch prong on their tails, not a lot will come near them.
The scientists return to what I can only describe as the mother ship.
No-one really knows why this animal grows so huge.
Could size, I wonder, be the key that allows a marine fish to invade rivers? Most sea fish die quickly in freshwater.
It's the larger ones that are best able to cope with the stress and survive.
There's one final sample to extract.
OK.
- Be careful.
- We are now going to take the toxin.
OK.
I'll hold here.
Collecting this thick, toxic mucus will help the scientists to discover, in more detail, how the venom works.
It's time for me to bid farewell to this river monster.
Though the jury's still out, if further research confirms that this fish does live exclusively in freshwater, then it probably is the biggest freshwater fish on the planet.
What's certain is that this is the biggest and strangest catch of my life.
Reunited with her babies, the mother stingray is set free and she returns to the dark depths of her hidden world.
I think she'll probably go back to all her friends with stories of alien abduction.
"They did experiments on me" and all sorts.
Personally, I feel like I'm the one who has seen the alien.
I mean, just what an amazing, totally un-fish-like fish.
I mean, a real monstrous beast.
From the depths of the Amazon to the suburbs of Berlin, I've been busy, tracking down the world's most frightening freshwater fish and uncovering the truth about their evil reputations.
It's taking line! That's taking line! I've tangled with man-eating catfish This is the one that goes after people, as well.
swum with piranhas and grappled with ferocious gar.
Agh! My next assignment is a beast of terrifying power.
It's spinning the boat.
It's taking the boat down.
Some people say this is the world's biggest freshwater fish.
If my line jams, it could pull me in.
This is a monster that can stab you with an eight-inch bayonet.
Its flesh-dissolving venom has no known antidote.
Just catching this fish will test me to the limit.
But my aim isn't simply to measure one of these giants.
I also want to know where it lives and how dangerous it really is.
- I've a feeling this could be - Agh! my toughest challenge yet.
- Here it comes! Here it comes! I think we're going to need a bigger boat! In just the past few years, a strange and possibly deadly creature has come out of the shadows.
I've read dramatic accounts of epic, six-hour battles and heard that this predator can inflict horrendous wounds.
Some people are even claiming that this little-known beast is the world's biggest freshwater fish.
The name of this monster is Himantura chaophraya, the giant freshwater stingray.
Shaped like a UFO, this Southeast Asian giant is said to grow to 16ft long and 7ft across.
Some sources put its weight at over 1,300lbs.
Even this basic information is very hard to verify.
It all sounds incredibly impressive, but how much of this stuff can I really believe? It seems that no-one knows how big this thing actually grows or why.
I've encountered river stingrays before, a thousand miles up the Amazon.
Here, they're known as "wish you were dead" fish, because of their agonisingly painful sting.
But these stingrays are relatively small.
The thought of a 16-footer sends a real shiver down my spine.
These are some examples of the wounds caused by marine stingrays.
Typically, what you're talking about is a very deep puncture wound, normally to the foot or the lower leg but sometimes higher up.
And the people generally talk about this as being extremely painful.
As well as the actual immediate wound, you have this very long-lasting effect of tissue necrosis.
It's just a very painful, messy wound.
Here's one from New Zealand.
You can see here that the barbs are actually still embedded in the leg.
The bit you can see is probably about five, maybe six inches long.
This is in the upper leg.
This person was very lucky.
If that had been a little bit further round, that could have punctured the femoral artery.
That could have been a fatal wound.
That could have killed him.
Note to self.
"Don't get stung.
" This is the barb from a stingray, actually quite a small one.
But you get the general idea.
The barb sits on top of the tail and it whips it over its back, a bit like a scorpion, or it can also whip it round to either side.
And looking at this, you can just see just how wickedly sharp that point is.
The second thing is you've got these grooves running underneath.
That is for delivering the venom from the gland at the base here, but also for making it a more efficient stabbing weapon.
You'll see exactly the same thing on a bayonet or a combat knife.
And the third thing, looking closely at this, you see these serrations along the edge here, and it works on the same principle as an arrowhead.
It goes in very cleanly but, you know, it's going to make a real mess when you pull it out.
Imagine being stabbed by a large steak knife, only this one's smeared with poison and it really shreds your flesh when it comes out.
Yep.
I've heard that the giant freshwater stingray has a barb that is eight inches long, which is a really sobering thought.
I'm quite curious to have a look at one of those, hopefully not too close.
It's not something I want to bring back as a souvenir in my leg.
My quest for the giant freshwater stingray takes me to Southeast Asia.
First, to Thailand's capital, Bangkok.
Surprisingly, this huge and potentially lethal monster lives right under our noses.
Normally, when looking for underwater monsters, you're thinking hundreds of miles upriver, in remote wilderness, but not this time.
I'm literally taking a short cab ride from the airport and I'm slap-bang in the middle of Bangkok and just a few miles away from the sea.
Even more incredibly, scientists only discovered the giant freshwater stingray a mere 20 years ago.
Its species name, chaophraya, comes from this very river, running through the heart of Bangkok.
And yet this monster in our midst is still cloaked in mystery.
I want to find out how big it really gets.
I also want to know how far this animal travels inland.
In most people's eyes, stingrays are sea creatures, not river fish.
Barely an hour's drive from the capital, I track down a story that puts me on edge and reminds me that the venom of this creature has no known antidote.
Four months ago, local fisherman Pun Sang was surprised to hook one of these rarely-seen giants.
For people here, such a huge fish is a potentially lucrative catch.
(Speaks Thai) The stingray came to the side of the river and then wouldn't come any further.
It basically got buried in the mud.
So what he had to do was get in the water, which was about chest-deep, and then completely go underwater with a rope, feed the rope through the spiracles, the water intake of the stingray, knot the rope.
He'd managed to pull it off the bottom.
It was actually as it rose in the water that he then felt this pain.
Argh! The wound was actually just numb to start with.
And then just this incredible pain.
In fact, so painful that he collapsed from the intensity of the pain and had to crawl the remaining distance to the house.
This was not going to go away on its own.
It did need urgent medical treatment.
As he races for help, Pun Sang continues to bleed heavily and almost passes out with the pain.
With no antidote available, his chances of survival are anyone's guess.
By the time he arrives for treatment, his condition is deteriorating fast.
- What happens at the medical centre? - (Speaks Thai) His heart rate spikes alarmingly.
Despite anaesthetic, he remains doubled up in agony.
The wound, in fact, is no more than a glancing blow.
And yet the pain proved so intense that Pun Sang is unable to work for the next four weeks.
He still has the very barb that impaled him.
Can I have a look at that? Right.
Well, seeing that really does concentrate the mind.
An absolutely vicious point on that and these horrible barbs down the side.
And I think you know, this is a fish I've got to really treat with some respect.
Evidently, even a quick jab from this fish can land you in serious trouble.
Whatever it contains, the venom seems every bit as potent as in marine stingrays.
OK, so that actually went in about getting on for three inches, there, but it was at an oblique angle, and So although he probably doesn't feel lucky to have had this experience, if that had gone in straight and punctured the femoral artery, that could have killed him.
Tragically, Steve Irwin, the Crocodile Hunter, was not so lucky.
He was struck clean through the heart and died.
While this freak accident happened way out at sea, the chilling fact about the stingray I'm looking for is that it swims up rivers, into some of the most densely populated parts of Southeast Asia.
And it's in these crowded waterways that I'm about to try and meet this monster face-to-face.
I head to a town called Samut Songkhram, 50 miles west of Bangkok and just a few miles inland.
This tidal stretch of river harbours some of the largest freshwater stingrays ever caught.
This fish, the giant stingray, was only described by scientists just 20 years ago, but, presumably, the people on these rivers have known about it probably for centuries.
The problem the scientists had was getting their hands on enough specimens to study.
What this means is either it's a very rare animal or it's just very, very hard to get one out of the river.
To try and catch one of these elusive giants, I'm teaming up with an experienced fishing crew, led by stingray enthusiast Boy.
Live bait is essential.
Its muscle movements will give off the electrical signals that stingrays use to detect their prey.
These animals are active hunters, prowling over the riverbed in search of a meal.
Their faces are packed with sophisticated sensors that penetrate the mud and murk.
Potentially eight times my size, this fish is in a different league from anything I've tackled before.
It calls for the heaviest gear.
I'm using ultra-strong braided line, with 30 yards of thick nylon monofilament at the business end.
To take some of the strain, I'll be wearing a harness.
Good news for my arms, but if the line digs in and jams, I could be pulled in.
Normally, the fish can't take line and the line will break, but when you're using a 160lb line, that line isn't going to break.
I'm going to go over the side.
After Pun Sang's account, I'm anxious to avoid this nightmare scenario.
If that's dug in, for some reason, I've got to have Plan B.
I'm going to be strapped to that, have a harness locked into that.
So I've got a knife.
If I'm going over the edge, the knife comes out and just cut that line.
The fish can go.
It's better than drowning.
With everything prepped, we head for the chosen spot.
A deep pocket in the riverbed they call "Area 51", because, as they say round here, it's crawling with aliens.
My battle boat is rigged with four big-game rods, including my own marlin-class outfit that I've brought for the occasion.
If a line goes, I'm ready to hunker down, strap in and lock horns.
To improve the odds, Boy's put out a dozen or so extra lines, tied to floats.
This isn't regarded as true sport fishing, but my mission here isn't to beat my chest or win prizes.
I simply want to see one of these incredible animals in the flesh.
And, within minutes, there's something big mauling our baits.
It didn't run off with the bait but there's been a stingray on that.
Something has come along and crushed that there, but, then, instead of taking the bait, it's spat it out.
Stingrays have crushing mouth parts that leave an unmistakable imprint.
Disappointing in one sense, but also good news.
I'm in the right place.
They are down there.
The next bite's a clean take and we are game on.
As I race to clip in, something powerful rips out several feet of line, then decides to tow us upriver.
It's spinning the boat.
It's taking the boat down.
I think we're going to need a bigger boat! OK.
Right.
Ah! Oh, yeah, that is Oh, look at that rod! That rod is now springing back slowly.
This line shouldn't go.
The rod's a bit of an unknown quantity.
Ah! It's my own marlin-class outfit taking the strain.
I just have visions of this rod suddenly shattering and getting a face full of fibreglass and carbon fibre.
That's pulling down.
That's pulling down.
There is quite a real possibility of this thing pulling me in.
I feel like I'm trying to pull the plug out of the river.
All I can do is dig in and keep the pressure on.
After 30 exhausting minutes, I haven't gained an inch.
Ah! Ah! This isn't like any fishing I've ever experienced and I start to wonder if I can cope.
Most fish, it's all over in five, 10 minutes, half an hour at the extreme.
You know, this In freshwater, something like this is just It's just unheard of.
With neither of us willing to give in, it becomes a war of attrition.
Give or take the odd foot of line, we're in total deadlock.
Be careful.
I've just been told it's one hour five minutes, so far.
We're into about round eight now.
Oh, look at that! It's taking line.
That is taking line fast.
This thing does not like being bullied.
I decided I'd show it who's boss and the fish is saying, "No, no.
You're not the boss.
" Ah! Oh! That's about half an hour's worth of work has just gone.
I've just gained about 3ft of line and it's just taken that.
But, sometimes, when it does that, the fish then takes a bit of a breather and I can maybe capitalise.
For another 40 minutes, we slug it out in a gruelling tug of war.
Right, I've got the initiative.
Whoa! Ah! Ah! Then, after almost two hours, a breakthrough.
I think it's come off the bottom.
There was a sudden Argh! A sudden sort of break of suction.
It does feel like it is actually Yeah, that's definitely coming my way a lot faster than it has done at any time until now.
My arms are cramping up and I'm close to breaking point, but I've finally got the measure of this gigantic fish.
It's about a metre and a half below the surface.
Here it comes! I'm just seconds away from seeing what must surely be one of the world's greatest river monsters.
Oh! Right, look at that.
The rod went.
The rod went.
I actually saw the fish.
We nearly, nearly had it in the net, but An almighty bang.
Oh! My gear was built to deal with sharks and marlin.
Whatever broke this rod could have weighed as much as 700lbs.
I thought it was my shoulder going for a minute, but it was the rod.
- Too long.
- The rod's too long.
Yeah.
Oh, dear.
That was so close.
The fish nearly came in.
We saw it.
After two hours, it was off the bottom.
We were trying to get the net round it.
The rod went and the fish escaped.
It wasn't quite in the net.
And to make matters worse, the fight has left me with a torn bicep.
All that suffering I saw the fish and it's Oh! All that for nothing.
All that.
Oh! It's score one to the stingray.
But my close encounter with this giant has got me wondering.
Why does this creature grow so huge? As this photograph graphically shows, marine stingrays are vulnerable to attack by sharks.
But what could possibly threaten a river stingray? Perhaps it's no coincidence that the rivers here are also home to another gigantic fish.
Growing up to nine feet long and weighing over 600lb, the Mekong giant catfish is a Class A monster.
Conceivably, the stingray's immense size could be a defence strategy.
To get a close-up look at a giant Mekong, I've come to a stocked fishing lake.
These animals are all but extinct in the wild.
This is a strong fish! Got the line against the This one's giving me the run-around.
A huge tail.
A huge tail on that.
But it's probably just a small one.
A very powerful sort of throbbing fight.
You can almost feel the beats of the tail.
That's a Mekong catfish.
My catch is only one-tenth the size of what they can reach.
Nonetheless, I can see it's no ordinary catfish.
Being a catfish, it's got no scales, but what's interesting, as well, although it's a catfish, it hasn't got feelers, barbels.
And the other thing that's interesting here is there's no teeth in there.
There's not even anything approaching one of these raspy pads in there.
Although this does grow very big and well over 600lb, it's not a predator.
This thing is a vegetarian.
It's a gentle giant.
If I'm looking down from here, I can't see any eyes.
The eyes are on the underside of the head, very close to the corner of the mouth.
That's something that just points to it being a bottom feeder, rooting around vegetable matter on the bottom.
So this gummy oddball isn't a killer, which leaves me still wondering why the stingrays here have evolved into such giants.
I've yet to see a chaophraya stingray.
Dead or alive.
But with Thailand's biggest fish market just down the road, I'm back on the hunt.
This is a vast clearing house for everything that comes out of the sea for hundreds of miles around.
Stingrays first evolved in the oceans.
And it could be that the giant freshwater stingray occurs in the sea, as well as rivers.
So we have got rays here.
I'm finding some rays.
That's not the one I'm after.
This is an eagle ray of sorts.
Yet another species of ray.
These are all marine species, but this is bringing home there is a huge diversity of ray species, lots of variations on the theme.
Stingrays are clearly one of nature's more successful designs, but their origins, some 200 million years ago, may come as a surprise.
A quick lesson in evolution here.
Here's a shark.
That is the classic shark mouth, the classic shark teeth, the shark tail.
Come to this fish here.
Shark tail.
Shark dorsal fin.
But something very different going on at the front end.
It's flattening, becoming squashed.
Let's flip it over.
And suddenly we've got a very different type of mouth.
Crushing plates but very different.
Gills on the bottom of the body.
Come to this fish here.
And here we have the same mouth, the same gills.
Flip it over.
There we have it.
A ray is basically a flattened shark, with this long tail.
This flattened body plan, with the eyes and water intakes on top, is an adaptation for life on the ocean floor.
Whatever its origins, the monster I'm after continues to elude me.
After three hours of trawling, I haven't found a single specimen.
I head to the freshwater stalls, where the fish are still pouring in.
If there are no giant stingrays coming out of the sea, then perhaps I'll find one here.
Any chaophraya here? (Speaks Thai) No? So no stingray here.
I don't know how many thousands of fish I must have seen here.
Thais really do love their fish.
They eat pretty well anything that swims.
But the freshwater ray is not here.
This could be because it's rare.
It could be because it's just hard to get out of the river.
Maybe there is another reason I don't know of, but I haven't found one.
To learn more about this elusive monster, I'm meeting a scientist who has more hands-on experience of this stingray than anyone in the world.
Dr Ning, from Chulalongkorn University in Bangkok, is one of the few people trying to study this animal.
Our first task is to collect some water from the bottom of the river, some 30 feet down.
One thing I want to know is whether this ray is a true river fish, living in pure fresh water.
That's on the bottom.
We're only six or seven miles from the sea here, so I'd expect the river to be quite salty.
In my mind, this puts a question mark over claims that the giant stingray is a true freshwater fish.
Now then, this is the moment of truth.
If this were pure seawater, the salt meter would give me a reading of 30, with brackish water at around 15.
So that is right on zero, which I'm quite surprised by.
It's very obviously tidal here.
I had my doubts about whether this thing is a truly freshwater animal.
I think that is something that still requires a bit of unpacking, perhaps, but it is certainly capable of living in water that it is absolutely fresh.
There's no trace of seawater at this point, at the moment.
In theory, they could be even further up these rivers.
While I'm here, I also want to find out more about the stingray's lair.
This stretch of water is less than half a mile from where I hooked the monster that broke my rod.
Ugh! Look at that.
That's what's on the bottom here.
Thick mud is going to give my quarry a big advantage.
They are going to get a very good seal and very good suction.
I now understand why I had such a battle to pull up this animal.
Imagine that's the stingray.
That weighs nothing.
I can lift that easily.
And Just getting a little bit under the mud.
There we go.
And I can lift it up.
Look at that.
- Argh! - (Laughs) So, if that stingray gets the edges of its wings under the mud, I'm not just lifting the stingray but the whole bottom of the river.
One of the things I want to find out about this fish is how heavy it gets.
For a small fish, you put it in a bag and weigh it.
For something the size of these, we've had to come up with something special.
Back at Area 51, our lines are set.
And I'm hoping my luck's about to change.
As we wait for a bite, Boy tells me an unnerving story.
heart here.
Made by heart go bump-bump-bump.
Sweat.
- And that's the scar of it there? - Yeah.
Just here.
I've just been asking Boy about stingray wounds, this kind of thing.
And he told me a story about how a small one just scratched him on the finger and he thought that's going to be fine.
15 minutes later, the entire left side of his body's gone numb.
The heart is pounding away.
He was thinking this could be like a snake bite, this could be fatal.
After three hours, it passed.
And I'm just thinking, you've just got to be so careful when handling these things.
With plenty of floats out, it's not long before I'm back in the ring.
This time, I've learnt my lesson and switched to a shorter rod.
It's my arm that worries me.
I'm not sure it'll take another 12 rounds.
To my relief, it's barely 20 minutes before this one starts to surface.
The fish is coming up! The fish is coming up! OK.
OK.
Are you ready, boys? So we've got the fish here in the net.
I've finally caught one, my first chaophraya stingray.
I keep well clear, though.
Until its sting is strapped up, this fish is still a loaded gun.
So this is just binding the barb, which sits in a bit of a groove.
That is binding the barb to the tail.
Once it's disarmed, we head for the bank.
Most of the body of the fish is in the water.
I haven't really properly seen this fish.
I'm really looking forward now to getting it in and having a proper look at this animal.
The pink tinge on the belly makes me think of the rash that divers sometimes get when they come up from depth.
This fish has surfaced from 30 feet down, enough to give it a mild case of the bends, so it's vital we release it soon.
This species is said to top 1,300lb, yet, as I now discover, this is only half the story.
We've got a male.
This one's a male.
The entire team is on hand to help measure and weigh the fish.
So this one's about four and a half foot across.
It's not particularly big as they go, but it is very big for a male.
Its sex explains why this one came up so fast.
Astonishingly, females can be up to eight times bigger than this full-grown male.
We've weighed it accurately, which is quite a hard thing to do.
175lb.
Around 80kg.
For sheer weight, this is one of the largest fish I've ever caught.
And yet, incredible as it sounds, it's a mere minnow.
It's been out of the water long enough now.
Definitely time to get it back in the water.
The males may be relatively small, but they're still armed with a potentially lethal sting.
Before we turn him loose, I go in for a closer look.
This is the business end.
This is why it's called a stingray.
This sharp, pointed poisonous barb on the tail end.
And it can throw this not only over its head, like a scorpion, it can throw it side to side, so that is the weaponry seen up close.
A very impressive bit of weaponry it is, too.
OK.
This is an animal that completely warps your normal sense of scale.
Despite catching a good-sized male, I know that my quest is far from over.
Since it was first scientifically described, there have been occasional reports of large chaophraya stingrays from far inland.
I'm leaving the tidal waterways around Bangkok and heading up country.
Could this be where I'll finally find my monster? I travel 150 miles north, following the Chao Phraya River upstream to a town called Nakhon Sawan.
But it's late May and the rains are starting to break.
As I begin to fish, the weather takes a turn for the worse.
(Rumble of thunder) For three hours, it pours without let-up.
All I catch is a dose of the monsoon blues.
(Rumble of thunder) At least someone's having some luck.
Then I meet a man with an amazing tale.
This was what, just here in Nakhon Sawan? (Speaks Thai) This is interesting.
This is a recent capture.
Only a few months ago.
I'm imagining that that wasn't easy to get out.
How long to get this out of the river? (Speaks Thai) Clearly, a very big fish, this.
Apparently 320kg, which converts to something like 700lbs, a seriously large fish.
The story is it took 10 people, in two boats, four hours to get it in and it actually dragged the boat well over a mile during that time, so I think a bit of an epic battle and a big fish.
Looking at the man's tackle, I'm amazed he got it in at all.
Ah, we've got a video clip someone took.
Obviously big local news.
There's people all around.
I'm no stranger to fishermen's yarns, but the figure of around 700lbs does ring true.
This fish was cut up and weighed accurately for market.
It seems they only kept one piece of it.
Oh, right.
- Is this from the same fish? - Yeah, same fish.
Ooh.
Right.
OK.
Even with its tip broken off, this barb is by far the biggest I've seen.
If there are giant stingrays here, then how much further upriver do they go? I'm starting to wonder.
Could these creatures have penetrated deep into the river systems, just like their distant Amazon cousins? Getting on for 3,000 miles long, the mighty Mekong is Southeast Asia's greatest river.
Until just the last 150 years, its upper reaches remained largely cut off from the outside world.
Even today, it still feels like a land of secrets.
If anyone can help me unlock them, it's the fishermen who make their living along its banks.
I'm now 1,000 miles upriver and I wonder if anyone here will know about the creature I'm looking for.
I wonder if you, fishing here, see any chaophraya? (Speaks Thai) The big-sized chaophraya or these were small fish? Any really big ones? (Speaks Thai) What happened there was that the stingray got wrapped up in the net.
This big one just broke its way through.
It sounds promising.
But I want a positive ID.
Will they recognise the fish from Nakhon Sawan? Same fish? (Speaks Thai) Yeah.
(Speaks Thai) So the same fish as here? (Man speaks Thai) Right.
This is very interesting.
I've shown the picture of the ray that was caught at Nakhon Sawan.
Not only is it the same species, it was also about the same size.
This was a big animal here.
That's a very encouraging bit of information.
It does bode well.
I'm going to be putting a bait in water where these things are.
Do the fishermen here try to catch chaophraya or is it always an accident? Do you Is it a good fish to eat? Do people eat it? (Men speak Thai) Ah.
OK.
OK.
So the stingray will come after the small fish in the net.
It's a nuisance species.
They try and get the fish that are in your net.
They get wrapped up themselves.
Then you've got to take them out and be very careful of the sting.
If you get a big one, they're actually going to rip your net apart.
So they don't fish for them.
It's a nuisance fish, they call it.
I head further upriver into even more remote country.
But the Mekong seems unwilling to give up its secrets.
Am I looking in the wrong place, I wonder, or fishing in the wrong season? My right arm still aches from the two-hour battle I fought and my exercise routine brings little relief.
Just curious looks.
Undeterred, I travel back downriver.
With a confirmed eyewitness account, I'm eager to take a look for myself.
I'm at a place called Nong Khai, right on the border with Laos.
25 years ago, I was actually in this very same bit of river.
A little bit upstream.
And I was arrested by the police on suspicion of spying.
And that cut short my entire trip.
End of fishing.
End of everything.
They locked me up for the night and confiscated all my photos.
This time round, I'm using sophisticated sonar equipment to scan the riverbed.
I'm looking down into the water.
I've got the sonar, 20 foot of water.
I'm trying to get a mental picture of the underwater geography, as my first step in looking for the stingrays.
I've actually got fish symbols straightaway, but they're middle of the water, unlikely to be stingrays.
Although, if there is something close to the bottom, it could be a ray.
They don't spend all the time just stuck right down.
Sometimes, they do actually rise off, maybe three or four feet and glide away.
I'm convinced there are giant stingrays down here, but before I can unpack my rod, there's a nasty surprise.
(Whoop of siren) One problem about here, it's the border between Thailand and Laos.
I might have possibly strayed over the border.
I'm just going to carry on acting normal.
I suppose I have got some fairly hi-tech gear on the boat.
I'm spying on the bottom of the river.
(Whoop of siren) OK.
OK.
Go in? OK.
OK.
They probably don't see that many foreigners on the river here.
I've been waved into the side.
I've been waved into the side.
They are still very, very keen on keeping an eye on people who do things by this border.
The border area is just very sensitive.
That's another difficulty in trying to find this stingray here.
The political situation.
I avoid jail, at least.
But I've no choice but to cut short my mission and head back south.
I'm starting to wonder if I'll ever see this elusive monster.
With one last throw of the dice, I return to Area 51.
My hopes of actually seeing the monster I've come to find seem to be drifting away.
To catch this seemingly rare and almost legendary beast, perhaps I need a little help from the gods.
I'm back at Samut Songkhram, where I've already caught a full-grown male and come painfully close to landing a truly massive female.
Just get the rods on first.
This time, the stakes are even higher.
A team of scientists has arrived from Chulalongkorn University in Bangkok.
They're counting on me to provide a live stingray for their research.
So little is known about this animal that every catch offers a rare chance to learn more.
The scientists will settle for any stingray I can catch, but, for me, this is all about seeing a true giant.
To hell with my sore arm, I'm just hoping we've hooked a big female.
I haven't come this far to miss out.
I get the illusion now that I'm actually bringing the fish to me.
What's actually happening is I'm taking the boat to the fish.
The fish isn't actually going anywhere at the moment.
What do you think? Is it a fairly good fish? Oh, it's just actually come off the bottom! It's a worrying sign.
Any monster worth its salt isn't going to give up so quickly.
But then the stingray sinks back down, switches gear and takes off upriver.
Oh! The drag on this reel is a little bit like the handbrake on a car and I've got that almost fully on.
The fish is basically just taking that line.
As I watch, at the moment, it's just going out one inch, two inches, three inches.
After half an hour, my opponent stops for a breather.
And I do the same.
Then we're back for Round Two and it's looking like a big fish.
Seven of us, on two boats, are dragged half a mile - against the tide.
Right.
It might surface! It might surface over there.
Now I've got the fish on the ropes, for the first time it feels like I'm driving the bus.
Under the boat.
I don't want to be lifting it while it's under the boat.
I think it's coming this way again.
It's just squashing my fingers! It's gone this way.
See the water there? I haven't seen the fish yet.
It is near the surface.
I've just seen the lead.
It's up in the water.
I think we've got it.
Back of the net, and this one looks pretty big, with an impressive 10-inch sting.
Head of the science team, Dr Ning first secures the barb.
(Speaks Thai) She's asked me to help her collect some venom before we release the fish.
It takes six people to heave this huge animal onto its front, into a position where we can measure it.
180cm to the base of the tail.
Going for the wingspan.
1.
91 metres.
Nearly two metres across.
1.
91.
At around six feet across, and roughly 400lbs, this female stingray is by far the largest river fish I've ever seen.
Little did I realise she was about to produce the mother of all surprises.
So we've just got the fish in to where the scientific team is.
And, literally, as we sort of pulled it into the net, it's actually given birth to two live young.
Dr Ning uses ultrasound to see if there are any more babies still inside.
This is the first time scientists have been able to collect data from the fully-formed pups of these stingrays.
Here, here.
On the ultrasound, the dark line is the cavity and there is a lighter shape inside it.
Apparently, that is the baby stingray still inside.
For me, this fish is a real first.
And not just for its size.
I thought I had one fish on the end.
It looks like I've got one, two, three, and another one inside.
Four fish, one hook.
Like many sharks, stingrays give birth to live young.
When they emerged, these babies had what looked like a small cap on their stings, presumably to prevent internal injury to the mother.
However, these safety catches soon drop off.
Within minutes, these twins are armed and ready to defend themselves.
It has been known for these fish to eject young when they are caught and if they are not well developed, there's a worry they won't survive.
The great thing about these two fish is they are pretty well fully developed.
They might be being born a little bit early, but I think they will survive in this river.
With that two-inch prong on their tails, not a lot will come near them.
The scientists return to what I can only describe as the mother ship.
No-one really knows why this animal grows so huge.
Could size, I wonder, be the key that allows a marine fish to invade rivers? Most sea fish die quickly in freshwater.
It's the larger ones that are best able to cope with the stress and survive.
There's one final sample to extract.
OK.
- Be careful.
- We are now going to take the toxin.
OK.
I'll hold here.
Collecting this thick, toxic mucus will help the scientists to discover, in more detail, how the venom works.
It's time for me to bid farewell to this river monster.
Though the jury's still out, if further research confirms that this fish does live exclusively in freshwater, then it probably is the biggest freshwater fish on the planet.
What's certain is that this is the biggest and strangest catch of my life.
Reunited with her babies, the mother stingray is set free and she returns to the dark depths of her hidden world.
I think she'll probably go back to all her friends with stories of alien abduction.
"They did experiments on me" and all sorts.
Personally, I feel like I'm the one who has seen the alien.
I mean, just what an amazing, totally un-fish-like fish.
I mean, a real monstrous beast.