99. Something fishy.

In 1950, a rather surprised angler caught a two metre Zambesi shark at the confluence of the Levuvhu and Limpopo Rivers in South Africa’s Lowveld.

Duuum dum. duum dum. dum dum, dum dum, dum dum, dum dum.

Duuum dum. duum dum. dum dum, dum dum, dum dum, dum dum.

This must have come as a little bit of a surprise, since the nearest ocean, the Indian, is over 400 km away.

Shark country.

Shark country.

The Lowveld is not however, a popular shark-fishing destination. This sort of thing had never happened before and has never happened since. In fact, the Lowveld isn’t well known for its fish at all. With good reason.

There are actually nearly fifty fish living down in the Lowveld. But you are simply almost never aware of them. The water, you see, is just a little on the dirty side. You could park a bright red Sherman tank just one inch below the surface of a Lowveld river, and you wouldn’t be aware of it until you swam into it while desperately trying to get away from a crocodile. And that crocodile should give you a clue as to how many fish there are here.

It didn't get that big by drinking protein shakes.

It didn’t get that big by drinking protein shakes.

There are seven permanent rivers in the Kruger Park, the main wildlife area of the Lowveld. In them live several thousand crocodiles. And crocodiles, despite what you see on the Discovery Channel, live mostly of fish, not wildlife documentary hosts. They do pull down the odd land creature, but that’s mostly just the very big ones. And they grow that big on fish.

It’s time for another Lowveld ecosystem post. I have been a little bit slack. I’ve been writing about the Lowveld for over a year now, and I’ve never mentioned the fish. So here goes.

The stupidest fish in the world.

I started off with a shark that had swum further up river than it should have, so let’s carry on in the same vein. I’ve always been fascinated by salmon. We are all so used to the idea of what they do that we don’t stop to think about what a remarkable thing it is. But it really is bizarre. Why? Why would an otherwise perfectly sensible fish, change its shape, give up on that whole eating thing, and leave its perfectly sensible home in the sea to swim up a river, spawn, and die when the sea seems like a perfectly adequate place for all the other fish to spawn and not die?

Is that a bear up there? That's it, guys, I'm going back to the sea.

Is that a bear up there? That’s it, guys, I’m going back to the sea.

It would seem, since the salmon’s closest relatives are the trout, that the salmon is a freshwater fish that found it was easier to live in the sea. It just never worked out how to breed there.

No. There are no Salmon in the Lowveld. We do, however, have eels. And eels, like salmon, cannot decide whether to be freshwater fish or sea fish. But they do it the other way around. The eels in the Lowveld are in what is called the feeding stage. They lurk around in that muddy, under-oxygenated water eating crabs and fish for a few years, or indeed decades, until they start to feel an unfamiliar itch. And then they start to swim towards the sea. 400 km away.

Luckily it's all downhill.

Luckily it’s all downhill.

This tends to take a while. But the time is not wasted. They use it to change into oceanic fish. They change from motley yellow to sleek, shiny silver. They get bigger and stronger. Their eyes get bigger and their snouts sharper. And then something even more peculiar happens. They lose their ability to eat. Literally. Their digestive systems wither away. They grow reproductive organs instead. And mate. All that remains is for them to swim to the other side of Madagascar to lay their eggs. And disappear.

The eggs drift down to the South African coast where they hatch into tiny, transparent larvae, which is how they drift along until the whiff of fresh water causes them to change into glass eels, at which point they start swimming upriver, changing slowly into the motley yellow Lowveld eels as they go.

And when they get there, they start the whole cycle all over again. It’s all just stupid. I get that it works, but why? Why not evolve to breed in fresh water? It’s warmer, and what’s more, it’s where you are. If you have to go to the sea, if that’s your “thing”, why the hell go round Madagascar? What’s wrong with our own sea? And if the sea is so damn important to you, why not stay there? I’ve heard reliable reports that there are actually fish and crabs there, and the water is cleaner, too.

It is, however, a little crowded.

It is, however, a little crowded.

Eels the world over do this. They head out to the most outlandish places to breed. I’ve actually heard the whole phenomenon blamed on continental drift. By all reports, the continents tend to drift around rather slowly. The theory is that the eels used to follow far more sensible migration routes. As the continents and oceans drifted slowly around the globe, so too did the eels’ final destination. But it never drifted far enough fast enough to warrant the eels sitting up and thinking “You know, this is all getting just a little bit silly”. It just moved a few millimetres a year, if that.

But now it’s drifted quite a long way, and all the other Lowveld fishes laugh as the eel’s eyes start to boggle and he dashes off downstream. To Madagascar.

Come on, kids, It's just a little bit further now.

Come on, kids, just another 1000km to go.

The tiger.

Nobody laughs at the tigerfish. South Africa doesn’t have many good indigenous angling fish. The fish round here don’t seem to put up the sort of fight that the people who like killing fish enjoy. This guy is an exception.

The fish guy, not the guy guy. He just loves killing fish that fight.

The fish guy, not the guy guy. He just loves killing fish that fight.

You can see why. He has the same sleek, muscular body as the trout or salmon. There is, however, just a little bit of a problem at the one end.

It's not called a tiger because it has stripes.

It’s not called a tiger because it has stripes.

Anglers prefer to fight their fish from one end of a long stick with some string tied to it. They do not like to fight their fish inside their boats at the risk of losing their fingers. So to go tigerfish angling you need to take along a special metal fish-holder.

The Fingersaver 2000.

The Fingersaver 2000.

The mystery fish.

This is the Tsiri River.

101_4005

It flows past my parent’s holiday home in the bush. For about two weeks a year. The rest of the time, it looks like this.

That is not, you will have noticed, a hippopotamus.

That is not, you will have noticed, a hippopotamus.

It occasionally comes down in something approaching the biblical flood, but most years it doesn’t rise to anything above ankle height, and flows gently for a couple of days afterwards before disappearing below the sand. Sometimes thirsty elephants will dig holes down to the water for a cool, refreshing drink, and then other animals will use it for a few days before the sand shifts over it again, but for the most part, it looks as dry and unforgiving as the Sahara.

But when it is flowing, something remarkable happens. Fish come swimming up the river. Quite big fish. We used to have great fun chasing after them, splashing through the ankle-deep water and shrieking like banshees. We never actually got one, but we would come pretty close when they powered through the shallows with more than half their bodies exposed, silver flanks glistening in the sun and bright orange fins sticking up like flags. They are called Bushveld Papermouths.

This guy was clearly a faster runner than me.

This guy was clearly a faster runner than me. The guy guy, not the fish guy.

I have no idea where they came from or where they thought they were going, but I cannot help but think that this was not a very smart survival tactic. Maybe they had swum up from the point where the Tsiri River had joined up with a permanent river. Maybe they had spent the long dry spell trapped in a few residual pools.

But it’s where they’re going that really makes me wonder. These aren’t the sort of fish that can survive buried in the mud. The best most of them can hope for is to find a shallow pool that lasts slightly longer than the receding waters, and then watch their new home slowly recede in the sun until the storks and leopards and hyenas move in and pick them off. There ain’t no promised land at the top of the Tsiri River for Papermouths.

The Weirdo.

You should be getting used to this by now. When it comes to the Lowveld, there’s always a weirdo. But this one is special. I’ve seen all the other fish on this list, but not this one. Almost no-one has. They were only discovered living in a few isolated pans in the Kruger National Park a few decades ago, and have now been introduced in a few more.

Because they're so pretty.

Because they’re so pretty.

Evolution took so long to emerge as a theory because you can’t see it happening. Usually. But if you see a Lungfish, it all makes sense. The lungfish is a very ancient fish, and it appears to be busy evolving into something else entirely. It cannot, you see, breathe underwater. Its swim bladder has evolved into a pair of lungs, and its gills have atrophied to the point where they no longer work. It has a pretty good reason for doing this. In most of its homeland, it lives in swamps where the water can be very poor in oxygen, so it has to rise up and gulp in fresh air. In the Lowveld, it takes things one step further.

At last, a pet fish you can take out for walkies.

At last, a pet fish you can take out for walkies.

It lives in seasonal pans, shallow dents in the surface of the ground that fill with water in the rainy season, but dry out to cracked, concrete-hard scrapes when the rains stop. As the water recedes, the lungfish digs itself a hole in the mud, and there it stays, trapped in the rock-hard dried mud ’til the next rainy season. Breathing.

That’s not all the Lungfish is up to on the evolutionary front. It also seems to have decided to learn to walk. It can swim like an eel, but spends most of its time walking around on the bottom of its pan on a set of creepy, Japanese-animation style tentacle-fins.

It's going to have to beef up a little before it takes a shot at dry land.

It’s going to have to beef up a little before it takes a shot at dry land.

I feel a little bit sorry for the Lungfish. In a few million years, it’s going to be ready. It will come strolling up out of the shallows, blinking in the bright sunlight and mentally giving itself a high-five for mastering that whole evolution thing, only to find that all the good spots are taken. And then it will sadly turn around and walk back into the water again, to set about re-evolving functioning gills.

The King.

Yes, the fish of the Lowveld have a king. But you can set aside any ideas you have of brave King Arthur clad in shimmering armour. This is a loathsome beast. A goblin king.

Nice crown though. Stylishly understated.

Nice crown though. Stylishly understated.

It’s called a Sharptooth Catfish. On paper. But we all just refer to it as a Barbel. So what makes it a king? Well, it’s the biggest fish in the Lowveld, for a start, if you don’t count the odd geographically challenged shark. It gets up to 1,4 metres long and weighs about thirty kilograms. There are perennial rumours of enormous man-eating barbel in South Africa’s bigger dams that are reputed to take small children. It’s the closest we can come to our own Loch Ness monster.

It apparently uglies them to death.

It apparently uglies them to death.

But that, as they say in the infomercials, is not all. Barbels are far and away the most widespread fish in the Lowveld. They can live almost anywhere. You find them in rivers and dams, in streams with largish pools, in sewage treatment plants and in sewers themselves, and in those same seasonal pans where the lungfish live. Which makes you wonder how they get around.

Most often, eggs are transported from one place to another on the legs of waterbirds. But they do have another trick up their sleeves. Sharptooth Catfish can walk across dry land. Or rather wet land. On rainy nights, they use two sharp spines to haul themselves up out of the water and crawl their way to another pool. God only knows how they know where they are going. The lungfish must look on with seething envy.  They can’t even feel superior about that whole lung thing, either, because barbell can breathe out of water, too, using specially modified gills. Smug bastards.

Cheers, guys. I'm just popping down to the shops for some smokes.

Cheers, guys. I’m just popping down to the shops for some smokes.

But wait! That’s not all. Their diet sets them apart, too. Barbel eat everything. Dead or alive, if it’s organic, they will happily chomp it down. They eat fish, crabs, turtles, baby crocodiles, waterbirds, small mammals, seeds, plants, and, if those Loch Ness rumours are to be believed, small children.

Their ability to live anywhere, on anything, leads to one of the bushes great spectacles. When a large pan that is home to several barbell dries out, the barbell do not die. Because they can breathe air, they can survive in the sort of squishy mud that feels good to squeeze between your toes. Or would if it wasn’t full of hideous goblin-fish. But when the pan dries out too much, the barbell have nowhere to run and nowhere to hide. And the predators move in for a feast.

You would think he would look just a little bit happier about the free meal.

You would think he would look just a little bit happier about the free meal.

Their ability to live anywhere, on anything might just let them take over the world. Because people have realised that they are pretty damn easy to farm. Most fish farms need to be incredibly carefully managed. You can get away with quite a lot on a barbel farm, though. Throw them in a muddy ditch and dump in all your agricultural waste, and Bob’s your uncle. They breed easily and grow quickly. And they have another advantage, too. In poor and hungry places, where there is no electricity, barbell can be sold live. Take a plastic bucket off to market and you can come home with your dinner so fresh it’s still swimming around.

In Africa, we take our sushi pretty damn seriously.

In Africa, we take our sushi pretty damn seriously.

This is fantastic for us here in Africa, but I see trouble brewing. People are trying to farm them in other parts of the world now, too. This is not smart. A fish that can live anywhere, and eat anything, is not a welcome introduction to any ecosystem anywhere. Throw in the fact that it can physically climb out of the water and wander off, and you’ve got an environmental catastrophe on your hands. Watch yourselves, Australia!

Well that’s it for me. Suppertime. I will not, as I’m sure you will understand, be having fish.

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35 thoughts on “99. Something fishy.

  1. narf77 says:

    Methinks some bright South African selection of sparks (most probably in their early 20’s and piss-drunk or in their late 40’s and also piss drunk…) might have decided that it would be a whole lot of fun to dump a shark that they caught in the river…much like the person who dumped a fox carcass in Tassie one day as a bit of a laugh and started an entire taxpayer funded industry for indolent native Tasmanian’s to manage our fox population. Don’t knock it, fox hunters abound in Tassie but in ten years and $40M spent, they are yet to catch a fox. Some bright spark worked out a way to sit around all day drinking beer and watching Honey boo-boo and getting us to pay a premium for it. Kudos to them I say and kudos to the morons who dumped that shark. Might be the making of a “clean green” shark watching industry in the Lowveld. I just changed my vote for what I think you should do after you finish your posts (obviously NOW Mr 23Thorns, an horrendous study unit from hell removed my comments from the equation while they may have still held a modicum of relevance to what you are up to at any given time…). I vote that you start a business (government funded of course) as a tour guide for shark sightseeing on the Lowveld.

    The eels have obviously evolved that curious lifecycle as a most selfless way to feed the crocodiles of the Kruger Park. Someone had to do it and way WAY back when natural selection was doing a paper-rock-scissors about just who was going to interact with what, the eels had no hands and ended up with the bum rap. Looks like papermouths got the bum rap too…again…no hands. I say the lungfish has seen the bad deal that the rest of the fish have had to endure and is waiting it out…they know that it takes a while for natural selection to come around to your way of thinking and so it has decided to do the breathing thing first (clever when the worlds water is drying up alarmingly) and THEN do the hand thing so once we humans have rendered ourselves extinct, the lungfish will be ripe for a takeover bid and by then those hands will be paper-rock-scissors ready. What else do you think they are doing in that mud under the Lowveld? Working out strategies that would make Garry Kasparov give up and go home that’s what!

    The catfish really rule the earth. They are the only fish species that can live anywhere, anytime, so long as there is a thimble full of water that they can splash around in. We have our own catfish problem in our mainland Aussie waterways. For once it wasn’t your fault! Our lords and masters from the U.K. decided that they were bored. Australia just wasn’t cutting the mustard for inland fishing so they imported their old mate “the carp” and released them with gay abandon into the nearest freshwater reservoir where they proceeded to go nuts. No natural predators, hunters who throw them back fondly when they catch them and suddenly you have a seething mass of hungry carp all going at our endemic natives with impunity. And as the queen is the boss we can’t even whinge about it!

    • 23thorns says:

      Yup. Thanks to our colonial overlords we have carp, bass, trout, and a whole lot more that don’t belong here.
      As for the sharks, it’s legit. They often swim up into fresh water- they must be trying to track down those eels before the crocs get them.

      • narf77 says:

        Same happens here…are you SURE South Africa and Australia aren’t the same place? Perhaps we are just existing in the same place in alternate realities…lets face it…have we ever commented at the same time? (now I am scared…I have to go to bed and hide under my pillow…)

  2. I love reading your blog and have passed the blog address on to pretty much every single one of my family (many of whom live in SA), I’m sure they’ll appreciate your brilliant writing as much as I do. (Sorry for the gushy comment – but I do love your site)!!

  3. katherinepage11 says:

    Reblogged this on Travel Agent Affiliate Program.

  4. mariekeates says:

    Well that would giver the fishermen down by my little river something to think about for sure!

  5. I do love your stories of the lowveld, and you’ve surpassed yourself with this one – fasciating! 🙂

  6. Jocelyn Hers says:

    I always thought, and now I know, living in Africa is never dull or mundane. Weird maybe, but boring, never.

  7. Art Brûlant says:

    Fish….Thanks……Barbel……wonderful fellows…..In Zim we used to have something called Vundu…or is that just a large Barbel?

  8. Well, you did it once again. Captured my attention. Will there be more forthcoming? Please, oh please. Say it isn’t true you will stop at 100!
    Leslie

  9. Arkenaten says:

    We don’t see many of these guys…fish guys, not guy guys, here in Jo’berg.
    Great Post.Thoroughly enjoyable read.

  10. ashokbhatia says:

    Great post. Keep them coming!

  11. Jim Morrison says:

    I live in the salmon hemisphere. And I am a biologist. So, a fish that hatches in freshwater and goes to sea to mature, returning to f/w to spawn is referred to as anadromous. On the other hand, one that starts in the sea, migrates to f/w to grow and returns to seawater to spawn/die is catadromous. Biologists words, only. But the interesting random weird fact is that there are more anadromous fishes in the northern hemisphere, and more catadromous fishes in the southern hemisphere. No explanation provided, it is what it is. Best wishes from Vancouver Island. Jim

  12. billgncs says:

    enjoyed it. Near the Great Lakes in the US we are dreading the Asian Carp as an introduced predator fish. Sounds like they wouldn’t have the walkover there that they have against our fresh water fish.

    Love reading about the animals and cultures there.

    Thanks

  13. Lyn says:

    Move over David Attenborough, there’s a new kid on the block 😀

  14. sheenmeem says:

    Thank you. My appetite has switched off at the thought of Barbel.

  15. Monica says:

    I especially love the section about eels. Who knew?

  16. Sue says:

    Another great wildlife post. I have a whole new appreciation of African fish now. Thanks!

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