December 15, 2007 Great Escape

[xoxoxoBruce]

From the Telegraph
Caught in the act, Brown Trout escaping from a UK fish farm, by leaping 3 feet into an 8 inch supply pipe. They swim against the current for 30 feet, to the river that supplies water to the farm.

[monster]

hope they survive in the river.

Grilled with almonds and a little fresh lemon juice should do it.

[coolcat]

"instinct" what exactly is it?.... Has it been scientifically explained? ...

[xoxoxoBruce]

A pattern of behavior, they do without knowing why. We know why but they don't.

[ZenGum]

Originally Posted by coolcat

"instinct" what exactly is it?.... Has it been scientifically explained? ...

Originally Posted by xoxoxoBruce

A pattern of behavior, they do without knowing why. We know why but they don't.

Also, a pattern that is not learned after birth but is programmed in, innately. Chicks imprinting on the first big moving thing they see is an example.
I've seen some "explanations" that I didn't really understand but which seemed to me to work for very simple behaviours.
For example, caterpillars that always climb up branches are in fact climbing towards the light. Boffins like to mess with them by putting light bulbs at the bottom of grass stems and watching them climb down. (with lights at either end and a toggle switch, they have hours of fun...)
Anyway it turns out that if one of the caterpillar's eyes is receiving more light than the other, this sends a signal which inhibits (slows) the movement of legs on that side of the caterpillar's body. Just like with a tank, one side moving slower than the other means it turns, in this case, toward the light.
It is an open question, just how far this sort of behaviour can go in terms of complexity. For these fish, some mechanism to make them "swim into the current" seems quite possible.

[Elspode]

Are we pretty sure that they don't just somehow smell that there's some strange wherever that water's coming from? That would really simplify all the speculation.

[xoxoxoBruce]

Not everything, that gets a whiff of something strange, runs away from home.

[morie]

hope they aren't genetically modified trout. then again, it's probably too late to think about that.

Morie
check out my website: www.anthology.page.tl

[classicman]

Originally Posted by xoxoxoBruce

Not everything, that gets a whiff of something strange, runs away from home.

not something strange...SOME strange. At least, thats the way I read it.


Fish were designed to swim UPstream or into currents. But these trout, much like salmon, are still amazing to me.

[Happy Monkey]

Their normal behavior is to swim upstream to mate, jumping up waterfalls along the way. They've already explored the whole pool, and the only "upstream" is the pipe, which is nothing more than a particularly tricky waterfall to jump.

But it's not like they don't have all day to keep trying.

[xoxoxoBruce]

Originally Posted by classicman

not something strange...SOME strange. At least, thats the way I read it.

Yeah, that's what I meant, your wording is more gooder.

[TheMercenary]

How do we know that the fish aren't just being spit out of the pipe backwards?

[Gravdigr]

When I first saw the pic, I hadn't read the story and thought it was a sewer pipe. I had this crazy mental image of some motherly English type sitting on a toilet, then letting out a whoop as a foot long brown trout tried to continue "swimming upstream". If you're picking up what I'm laying down...

[Gravdigr]

Originally Posted by TheMercenary

How do we know that the fish aren't just being spit out of the pipe backwards?

The fish look pretty calm, so I think they're swimming upstream. If they were coming out backwards, they would look scared as hell...