On Tue, 15 Jun 2004 18:50:41 -0500, "Wolfgang"
wrote:


"Willi" wrote in message
...


Tom G wrote:

Now I'm wondering about the lack of survival skills in hatchery fish.
How many of them fail to thrive in the wild because they don't know
how/what to eat?

I think it goes beyond that but I did read about a study that tried to
do what you're suggesting - I can't remember the results.

Most trout that are raised to catchable size before stocking are from
lines of fish that were developed to do well in hatchery runs (at least
this is true in Colorado). They selectively bred for fish that would
gain the most weight in the shortest amount of time in a runway
environment. It pretty obvious to me that those fish aren't going to do
well in a natural environment even if they know what to eat.

When fish are hungry, they WILL eat. I'm going to guess it doesn't take
them long to figure out the difference between a pebble and a plecopteran.
If they're thirty days from the hatchery and they're not dead?..........

Wolfgang

A couple weeks ago we kept some stocked fish from a local lake. There
is absolutely zero reproduction and I would guess little carryover
from year to year. They all had natural food in their stomachs ranging
from damselfly nymphs to midge pupa. From what I understand it is
instinctive behavior for trout to mouth things drifting in the water
column as a way of investigating them.


g.c.