#30454: coturnix — 06/30  at  07:17 PM
Oh, I've seen 200kg catfish in the Zagreb aquarium. Those things can be huge. My father's cousin is a professsional fisherman on the Danube and, during the carfish season, he regularly pulls out several dozen large ones every day, regularly as long as 1m and occasionaly bigger! The smaller ones taste better on the grill. The big ones are great for soup or stew.

#30455: Martin Wagner — 06/30  at  07:23 PM
It is sobering to be reminded how big those suckers can get. Bet those steaks were yummy.

Seems to me the giant-catfish concept has been inadequately explored by low budget horror filmmakers....

#30460: — 06/30  at  09:05 PM
A single steak looks like the cross section of a small cow. Nature's just being silly now.

-Schmitt.

#30461: — 06/30  at  09:14 PM
There's an aquarium in Zagreb? I spent a month there in '97 with a friend and he never mentioned it... oh well, I really wanted to go back anyway.

This fish is huge! I thought the 2 - 3 foot ones that live in the creeks around here (Northern California) were big. Shows what I know about big fish.

#30476: fwiffo — 07/01  at  06:23 AM
Since catfish are bottom-feeders, aren't very large ones going to be saturated with things that are quite bad for you?

#30477: Martin Wagner — 07/01  at  06:38 AM
You mean, like swimmers and skiers?

#30478: Raven — 07/01  at  07:09 AM

Since catfish are bottom-feeders, aren't very large ones going to be saturated with things that are quite bad for you?

That's precisely why they taste so good.

Mmmmmm...nothing like fried catfish--one of the few things I miss about Alabama.

#30479: Raven — 07/01  at  07:19 AM

Seems to me the giant-catfish concept has been inadequately explored by low budget horror filmmakers....

Especially the walking ones.

#30480: fwiffo — 07/01  at  08:04 AM
I did see a documentary once on this amusing practice.

#30481: Hank Fox — 07/01  at  08:36 AM
After I found out what catfish eat, I quit eating them -- despite growing up in Texas and Alabama. I've handled and skinned catfish, and they're waaaay down low on my list of Wonderful Wildlife. (If we ever meet intelligent aliens, I hope they're not descended from something like catfish, because I'll freak.)

Re: Horror film makers and giant catfish. When I was taking scuba diving lessons, one of the stories the Old Hands told us easily-made-uneasy novices was that there were catfish in Lake Houston with mouths that were two feet or more in diameter. No diver had ever seen more in that dark water than the mouth, looming up out of the murk.

One of the news stories said that that river where the giant cat came from -- the Mekong? -- contained more giant fish than anyplace else. I wasn't sure whether it meant more giant catfish, or more giant fish of several different kinds. But I wondered why.

#30485: Ron Sullivan — 07/01  at  09:29 AM
Aw, come on, Hank, think about what shrimp and crabs eat. isn't it great that they can transform um debris into yummy shrimp and crabmeat? Ditto catfish. And the southeast-Asians have some great catfish recipes.

The Mekong has other giant fish species -- giant freshwater stingray, sawfish, like that.

Nat'l Geographic

#30488: — 07/01  at  09:44 AM
The guy from the WWF is named Hogan. lol.

#30494: Raven — 07/01  at  11:07 AM

Re: Horror film makers and giant catfish. When I was taking scuba diving lessons, one of the stories the Old Hands told us easily-made-uneasy novices was that there were catfish in Lake Houston with mouths that were two feet or more in diameter. No diver had ever seen more in that dark water than the mouth, looming up out of the murk.

Sounds like an old diver's tale to me. It's a very macho sport, where scaring the newbie is de rigeur--damn, I miss it, since my abdominal surgery left me undiveable. What could be cooler than a sport where you get to drink beer and walk around with a knife strapped to your leg?

Hank--do you know what the dive knife is for, by the way? <dive humor>It's in case you're confronted by a shark--first you stab your buddy in the side, before you swim away.</dive>

One of the news stories said that that river where the giant cat came from -- the Mekong? -- contained more giant fish than anyplace else. I wasn't sure whether it meant more giant catfish, or more giant fish of several different kinds. But I wondered why.

I never heard that, but it wouldn't surprise me--the headwaters of the Mekong are in Tibet, so by the time it reaches the ocean, it's had a couple thousand miles of land along its route to leach silt out of, making it extremely fertile.

#30502: HP — 07/01  at  01:08 PM
Don't forget about the giant turtles living in downtown Hanoi. What's remarkable to me is the presence of all these giant species such close proximity to large and old human population centers.

Re: Giant walking catfish horror movie: It's been done. Plot summary. Review s/screen caps.

#30507: coturnix — 07/01  at  01:41 PM
HP, that is hillarious! Watch the clip!

#30516: Raven — 07/01  at  03:49 PM

What could be cooler than a sport where you get to drink beer and walk around with a knife strapped to your leg?

I totally forgot to mention peeing in your wetsuit.

Good times.

#30550: John Emerson — 07/01  at  10:01 PM
The paddlefish of the Yangtze and Missouri rivers is also amazing.

It's under pressure in both places, and while SD seems to be protecting it, Montana doesn't seem to be trying. Caviar can be made from its eggs. Up until recently they were just randomly killed and mostly wasted. Largest recorded is ~130 lb., but it is believe that much larger ones once existed.

http://www.nativefish.org/articles/Pre_paddlefish.php


http://www.npwrc.usgs.gov/resource/wildlife/sdrare/species/polyspat.htm

#30556: Hank Fox — 07/02  at  12:00 AM
Raven, Re: peeing in your wetsuit.

Another thing they told us is that if you get stung by jellyfish and don't have any jellyfish-sting-treatment stuff with you, the workaround is to have your friends urinate on the stung area.

So you don't just get to pee in your wetsuit, oh no! Scuba diving is like a continuous Golden Showers adventure.

Hey, since you seem to know about scuba diving, lemme axe you a question: WHY do scuba divers not learn ASL? It was a total no-brainer to me that they should. I mean, those little signals like "need air" and stuff are okay, but jeez, you could hold entire complex conversations underwater with American Sign Language. They could at least learn finger-spelling.

Okay, it's been ... um, like 30 years since I did it, and probably a lot has changed. But has this?

#30558: Raven — 07/02  at  01:08 AM

Another thing they told us is that if you get stung by jellyfish and don't have any jellyfish-sting-treatment stuff with you, the workaround is to have your friends urinate on the stung area. So you don't just get to pee in your wetsuit, oh no! Scuba diving is like a continuous Golden Showers adventure.

Yes, it's true. I've never seen any other "sport" that is so polymorphously perverse. Sadly, though, despite many other barriers for women coming down, I would have been so inadequate at the jellyfish cure for my dive buddies. I never was able to master peeing off the side of the dive boat, either.

Hey, since you seem to know about scuba diving, lemme axe you a question: WHY do scuba divers not learn ASL? It was a total no-brainer to me that they should. I mean, those little signals like "need air" and stuff are okay, but jeez, you could hold entire complex conversations underwater with American Sign Language. They could at least learn finger-spelling.

That's a good idea, Hank--I can think of one, and possibly two, reasons they don't, but it is a good suggestion. I'd even be willing to come up with specialized signs for things like different kinds of fish to communicate about.

The most likely reason I would think is that learning ASL takes more work and study than a lot of people would be willing to do. The second possible reason, and I'd have to try this out before I considered it more than just a hypothesis, is that possibly the water resistance against large sweeping arm motions at depth might increase oxygen uptake enough to seriously cut into the time you could spend underwater.

If I could still dive, I'd time a dive without arm signs, and then time a dive continuously signing, and see how long my oxygen lasted in each case, to test that hypothesis. But if I ever breathe compressed air at depth again, I'm at risk of pulling an "Aliens" when I surface, so this will remain a thought experiment for now.

But even if ASL is prohibitive for either or both reasons, I agree with you that finger-spelling would be totally useful at depth, and that shouldn't increase oxygen uptake too much. It's a great idea.

#30574: — 07/02  at  09:30 AM

The second possible reason, and I'd have to try this out before I considered it more than just a hypothesis, is that possibly the water resistance against large sweeping arm motions at depth might increase oxygen uptake enough to seriously cut into the time you could spend underwater.

Could it not also have something to do with:
a) it being dark underwater, and thus hard to see (at least when you are far down).
b) the movement needed to communicate might disturb.... something.

#30713: — 07/03  at  05:34 PM
"The catfish is a plenty good enough fish for anyone," says Mark Twain.

Stop saying that catfish are not wonderful, or I'll sic Sparky on you. (Of course, you'd have to come over, stick your arm in the tank, and even then, also do something to startle or annoy her. Still. Desist!)

Large intelligent ambush predators are definitely Wonderful Wildlife. And many catfish are definitely predators, not just scavengers. (If you dislike scavengers, start dissing bald eagles.)
Especially wonderful, I think, are the ones that can shock you if you aren't polite, or are food.

Africa has several species of electric catfishes, Malapterurus electricus among others of the genus. They're strongly electric fish, which means they use their electric organs for defense and hunting in addition to navigation and prey-finding. The big species can get to be 1.2 m long, and can zap out 350-400V at will.

A catfish shock is no joke, let me tell you. The ancient Egyptians, fishing with nets in the Nile, named it "the one who rescues many." There's even a bas-relief of the unmistakable fish in a pleasant boating-and-fishing scene. Empirically, the ol' Electric Organ Discharge from a 24-cm fish (standard length = snout to base of tailfin), in a small (29-gal, ~110L) tank, easily knocked my arm out of the water. The external electrical input overwhelms the internal nerve signals in the hand & arm muscles, and the muscles all contract. (Very fun: opposing muscles contracting at once.) (And the arm feels wigged for about 10 min afterwards.) In the bigger 65-gal (~250L) tank, the EOD of my now-29cm fish just makes me drop whatever I'm holding and jerk my hand a little -- the jolt doesn't freak out the nerves above my elbow anymore. It's a bigger shock, but "diluted" in a lot more water, or rather, attenuated by (the cube of) more distance.

Also, big predators are smart. Sparky is smart enough to recognize individual people, at least chemically, at least between Steff vs. non-Steff. Evidence?
Sparky lets me pet her snout. (Imaginary proud smiley-face here.)
She's even bumped into my hand (me: cleaning, not paying attention) on purpose a few times without firing.

Also, big predators are capable. This fish has near-superpowers for sense organs.
Mechanoreceptors: touch (duh), real working ears, and a lateral line.
Chemoreceptors: a nose served by 4 cute tube-like nostrils (2 incurrent, 2 out), and taste buds all over her skin, especially densely on her barbels (the whiskery-looking thingies, don't you wish you had those?!) and fat pouty lips.
Photoreceptors: unlike their South American electric eel pals, e-cats can see just fine with their small but entirely functional eyes.
Electroreceptors: arrayed symmetrically on the fish's face, tiny (0.5 mm) bumps have teeny holes leading to little chambers lined with electroreceptive cells. Sparky does get interested when I use the magnet-scraper on the tank. She follows the moving magnet around. She doesn't pay any attention to it when it's not moving. A moving magnet sets up an electrical field. Those receptors work.

Of course, she also has enviable (to us scuba divers) buoyancy control and powerful swimming. We had a foot of 3" PVC pipe set up as a flume for her for a while, with a small (300 gal/h) submersible pump aimed through it. She bulled up it about once a day; she often sailed downstream too, tail splayed and cocked sideways to catch the current. Oh, right -- smart enough to play, too.

You don't have all that if you only scavenge. Big catfish are deadly predators.

There are, of course, also vegetarian catfish, and wood-scraping catfish, and plenty of omnivorous catfish, and isn't your fishtank ecosystem better off thanks to them?! Not to mention gill-parasite catfish and blood-sucking catfish. There's even a terrestrial catfish that lives in damp South American leaf litter, and crawls back out if you put it in the water.

Hank and others, if all you have to go on are pond-reared American ictalurids, well, I can sort-of understand the sentiment. But catfish in general are splendid. The Mekong giants are fabulous, and I'm sad that big one is dead.

For more, try starting at Planet Catfish, http://www.planetcatfish.com/core/

#30739: — 07/04  at  12:05 AM
On another subject,

The second possible reason, and I'd have to try this out before I considered it more than just a hypothesis, is that possibly the water resistance against large sweeping arm motions at depth might increase oxygen uptake enough to seriously cut into the time you could spend underwater.

Could it not also have something to do with . . . the movement needed to communicate might disturb.... something.

I'm sure there are ways for fluent ASL speakers to sign in small-gesture words.
But, like learning any language, becoming fluent takes a lot of work.

Divers generally want to minimize what they have to learn before getting in the water. We don't tend to memorize even the basic set from dive school, besides the two critical ones, "low on air" and "go up now."

I agree that knowing finger-spelling would be useful. I've been on a lot of research dives with a lot of different objectives and with a lot of different buddies. Finger-spelling would have drastically reduced the confusion many, many times. If only we'd been able to see the buddy's fingers clearly.

The problem is that, apart from the low vis, the thick black gloves make finger-spelling difficult and inobvious, while mitts make finger-spelling impossible.

People that have to communicate undewater either use a rig that will let them actually talk (hard-shell helmet and radio), or bring a writing surface and a pencil. Research divers use "slates" made of a 5-6 inch long section of PVC pipe around the forearm. You can tape waterproof paper or architect's mylar to the "slate" and keep the original of your data forever that way -- along with the inevitable stupid conversations in all-caps (for speed and clarity): "WHERE EXP'T?" "USE BOWLINE" "NO -- REAL BOWLINE" "WHERE INTERN?" "ANCHOR?!"

#30794: — 07/04  at  11:22 AM
I love catfish, the people there probally appreciated such a huge fish for dinner.. and dinner the next day.. and the next..

#30958: — 07/06  at  05:31 AM
Once, while on a trip on the Allagash River in Maine, some friends of mine and I caught a catfish in a canoe. No, I don't mean we were fishing from the canoe and caught a fish, I mean we swamped the canoe, and when we dragged it out of the water there was a fish inside of it.