Sunday 17 June 2012

Paddlefish

Image: Joachim S. Müller via Flickr
All hail the mighty schnoz of the ancients!

They just don't make 'em like they used to. The Schnozzlefish... sorry... Paddlefish is a fish with a massive, paddle shaped schnozzle... I mean rostrum.

They are close relatives of the Sturgeon and, first emerging around the early Cretaceous Period, almost as ancient.

You can see the family resemblance in their skeleton, made mostly of cartilage rather than bone, and their shark-like, asymmetrical tail fin. You may remember that this asymmetry is not simply having one lobe longer than the other, rather their very spine goes right up to the tip of the upper lobe.

Both of these characteristics are shared with sharks, even though Sturgeons and Paddlefish are actually bony fish. Stranger still is that the Paddlefish is remarkably akin to our old friend the Basking Shark. You need only see them with their mouth open.

Image: tetzl via Flickr
Paddlefish are freshwater plankton eaters. They swim around in murky, slow-moving rivers, filtering out miniscule meat products using gills so big they're an inch or two away from decapitation.

They've been around for a long time so I assume they know what they're doing, but I would personally prefer to do that kind of thing in crystal clear water. I DEMAND the soothing taste of chlorine. Then again, all those tiny crustaceans and stuff they're eating are all things I wouldn't want in my mouth anyway, so I guess it depends on your objective.


Paddlefish are obviously not as big as Basking Sharks, but they can still be serious river monsters.

There are two species. The American Paddlefish lives in the Mississippi and various other rivers that drain into it. They can grow to 2.2 metres (7 feet) long and weigh up to 100 kg (220 pounds)... not bad at all. I'd certainly be respectful if we met down the pub.

Even more impressive and tragic is the Chinese Paddlefish. If they live still, they live in the Yangtze River.

Image: Wikipedia
Chinese Paddlefish
Unfortunately, that's a very big 'if'.

They've been endangered due to overfishing for decades. The last confirmed sighting was in 2003, though there's a story of a 3.6 metre (11.8 ft), 250 kilogram (550 lb) specimen captured illegally in 2007.

Was this the last of its kind? There hasn't been a young Chinese Paddlefish spotted since 1995, so the odd leviathan here and there may simply be a ragtag of loners who haven't seen one of their own in decades. This is especially the case with all the new dams in China splitting up whatever population may be left.

This is terrible not only for the loss of an animal - and a magnificent one at that - but there are also stories of Chinese Paddlefish reaching 7 metres (23 feet) long. This would be extraordinary! It would be about the length of an average Basking Shark! And we will probably never know if such a thing is even possible.

:(

In these dark times only one thing can lighten the mood - contemplation of Paddlefish schnoz.

Image: Aaron Gustafson via Flickr
Paddlefish and paddle.
At least in the American Paddlefish, that extraordinary facial furniture is full of sensitive electroreceptors. Just like the Sawfish and Saw Shark! It may well be used to detect the presence of prey.

Another idea is that it's used to provide lift so that the Paddlefish doesn't sink head first into the mud. It was once thought to be used for digging up food or as a kind of carpet beater for whacking munchies out of foliage.

The strange thing is that Paddlefish have been found with a damaged or missing rostrum and a belly full of food to go with it. One wonders exactly how much they really need that crazy face?

Well, another thing those electroreceptors are good for is avoiding bumping into things in their dark, dirty waters. This is of particular use when they migrate to their spawning grounds.

Image: Joachim S. Müller via Flickr
They'll only do this when the time of year and the water temperature is right, at which point the female will dump a few hundred thousand sticky eggs into the river, the male will fertilize them and off they go without a second thought.

The eggs sink to the substrate and get eaten. Let's face it. But some will win the lottery and hatch, hatch gloriously into the dark, dingy river water. I would still want it crystal clear. Maybe I'm just a pansy?

With their eyes useless in the murk, young Paddlefish have been seen using their rostrums to detect plankton from up to 9 cm (3.5 in) away. I think Pinocchio would've lied a lot more if it meant receiving a superpower like that!

So perhaps that sniffer is of some use after all? I hope the American Paddlefish keeps it for a long time to come. There's nothing in the world quite like it, any more.

6 comments:

TexWisGirl said...

the ones missing their schnoz must really get teasing from the others! usually it's the kids with the big noses that get picked on...

Joseph JG said...

Ha! Well it's nice that noses can find a place to win!

Anonymous said...

Lol, upon seeing the pictures, I immediately thought that this was some kind of tiny basking shark. And after reading the text I knew I was not the only one who thinks so! (and that it is not in fact that "tiny")

Joseph JG said...

Yes, they really are freshwater Basking Sharks. I find that a remarkable fact. I had never even heard of large fish filter feeding in lakes before!

BK said...

The Chinese paddlefish is(was...) so unlike its American cousin (much bigger, and a predator not a filter-feeder) that it's even stranger.

Joseph JG said...

Yikes! Deadly schnoz!