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[zap brannigan]

All of them quotes cover salmon Dave not steelhead, I've found all sorts of things in their stomachs and by the sounds of it so have others
I think that suggests that they do eat in freshwater and I don't see why the stomach contents wouldn't be digested, steelhead are repeat spawners unlike pacific salmon they wouldn't survive the lengthy stay in fresh and journey back to sea without feeding.

[Dave]

All of them quotes cover salmon Dave not steelhead, I've found all sorts of things in their stomachs and by the sounds of it so have others
I think that suggests that they do eat in freshwater and I don't see why the stomach contents wouldn't be digested, steelhead are repeat spawners unlike pacific salmon they wouldn't survive the lengthy stay in fresh and journey back to sea without feeding.

Spawning steelhead undergo the same physiological changes as spawning salmon.  Yes they eat things but because of these changes they cannot digest them.  Next time you kill a hatchery steelhead, notice how hard and atrophied the stomach and pyloric caeca are … compare that to the soft and elastic stomach tissue of say, a lake rainbow trout, pikeminnow, etc.

[greyghost]

Thanks for the Salmon Info Dave. That was much appreciated! Now lets get back to Steelhead!
How does a summer-run survive all that time in fresh water? They must go in a hypnotic state "trance" like sturgeon do in the winter.
Oh ya, I forgot that I killed one with a bullhead in its stomach!

Dave, have you killed a Steelhead in the Salt H2O and compare the tissue samples with one that was caught in fresh water?

[greyghost]

Wait, a fish enters fresh water in June and then swims around just hanging out 9/10 months until January or February before they spawn?

That is a steelhead though.

More like March/April.

[Dave]

Thanks for the Salmon Info Dave. That was much appreciated! Now lets get back to Steelhead!
How does a summer-run survive all that time in fresh water? They must go in a hypnotic state "trance" like sturgeon do in the winter.
Oh ya, I forgot that I killed one with a bullhead in its stomach!

Pacific salmon are the same genus as steelhead, and if the sculpin you found in a steelhead was even partially digested that would be relevant.  Was it?

OK, let's try a different tact.  If upstream migrating steelhead are able to digest food that means stomach excretions and enzymes are active … that also means an empty stomach would trigger a feeling of hunger and a search for food.  Consider the Vedder gets a few thousand steelhead annually, average weight about 12 lbs; what do you think these fish would survive on if they had to rely on catching food?
If steelhead were indeed actively feeding and digesting what they captured, none would make it above the gauntlet of anglers and these fish would be long extinct. Being able to survive upstream migration without eating is a tactic that has worked for a long time for anadromous species.
Sure, it's hard to believe these fish survive for months without added nutrients, and may be a reason return spawners are very low in numbers, but it's true. It's much like how does a Stuart sockeye swim all that way up the Fraser simply by surviving on fat reserves?

[bederko]

       Actually summer steelhead caught in the wild and brought into a holding facility can be easily trained to feed on salmon  eggs and then hatchery food.
After spawning they can be held and  fed for another year and then spawned again.
Wild winter steelhead can also be trained to fed in captivity and I believe this practice aids their survival chances when released post spawn.

[greyghost]

As for the sculpin. It sure was in the process of being digested!

Pacific Salmon are the same genus as steelhead! Come on Dave, that has been proven false already! I am not trying to belittle you but you might want to do a search under Oncorhynchus Mykiss. If anything a Steelhead is more of a relative to the Atlantic Salmon than the Pacific species! I am not on here to make bs up. The facts are out there.

Get your mind off of the Vedder Winter-Runs and think about the summer-runs. To different species but with the same DNA traits.

Dave, will a summer-run spawn with a winter-run when they are prevalent in the same river system?

PS I am shocked the Boss hasn't blocked my posts already!

[greyghost]

       Actually summer steelhead caught in the wild and brought into a holding facility can be easily trained to feed on salmon  eggs and then hatchery food.
After spawning they can be held and  fed for another year and then spawned again.
Wild winter steelhead can also be trained to fed in captivity and I believe this practice aids their survival chances when released post spawn.

Thank you bederko!

[Dave]

       Actually summer steelhead caught in the wild and brought into a holding facility can be easily trained to feed on salmon  eggs and then hatchery food.
After spawning they can be held and  fed for another year and then spawned again.
Wild winter steelhead can also be trained to fed in captivity and I believe this practice aids their survival chances when released post spawn.

That is news to me bederko.  Any links or further information??

[firebird]

Here's a link to an abstract of a related paper. You'll have to go to a library or buy it online if you want to read the whole thing. What I gather is that there is some "shut down" of the digestive system of steelhead. A partially digested sculpin could have been in a summer run's stomach for who knows how long. Anyway, I think Dave is partially right and bederko indicates that steelhead can make use of food to some extent. According to the paper, they recover rapidly after spawning and then start feeding. Everyone knows how voracious a kelt is.

http://link.springer.com/article/10.1007/s11160-013-9338-2#page-1

[Dave]

Here's a link to an abstract of a related paper. You'll have to go to a library or buy it online if you want to read the whole thing. What I gather is that there is some "shut down" of the digestive system of steelhead. A partially digested sculpin could have been in a summer run's stomach for who knows how long. Anyway, I think Dave is partially right and bederko indicates that steelhead can make use of food to some extent. According to the paper, they recover rapidly after spawning and then start feeding. Everyone knows how voracious a kelt is.

http://link.springer.com/article/10.1007/s11160-013-9338-2#page-1

More good sleuthing!!

[Dave]

As for the sculpin. It sure was in the process of being digested!

Pacific Salmon are the same genus as steelhead!

Get your mind off of the Vedder Winter-Runs and think about the summer-runs. To different species but with the same DNA traits.

No, same species (Onchorhychus mykiss   ), just a different life history and run timing.  I have a friend and fellow FWR contributor who fishes the Stamp, a system with both summers and winters .. he may want to respond to your question regarding spawning between the two.
You may recall this thread was started with my opening the stomach of a Vedder winter run, but your inclusion of summer runs is good.

[bederko]

Feeding summer runs was a personal project I experimented with. The fish were brought into the hatchery in Sept.- Oct. and were extremely thin by spawning in Feb. - Mar.  We also had problems with fungus and I couldn't see how a fish could fight infection without nutrition so I started feeding them surplus F.V. trout eggs. ( post malachite era) Within a few weeks you could literally feed them out of your hand. Reddish fish poo had to be brushed through the drain daily. I don't know if the colour indicates partial digestion or not but I can say that the condition factor of the fish increased greatly. Egg survival remained the same for both fed and unfed fish but there was a reduction in fungus problems for fed fish. Because of the success of this experiment, not in egg survival but in fish health appearance we started feeding winter runs and cutthroat.

As for summer winter cross breeding  There wouldn't be summer winter fish if they cross bred in the wild.

[Rodney]

Pacific Salmon are the same genus as steelhead! Come on Dave, that has been proven false already! I am not trying to belittle you but you might want to do a search under Oncorhynchus Mykiss. If anything a Steelhead is more of a relative to the Atlantic Salmon than the Pacific species! I am not on here to make bs up. The facts are out there.

You might want to check up on that again.

[Dave]

Feeding summer runs was a personal project I experimented with. The fish were brought into the hatchery in Sept.- Oct. and were extremely thin by spawning in Feb. - Mar.  We also had problems with fungus and I couldn't see how a fish could fight infection without nutrition so I started feeding them surplus F.V. trout eggs. ( post malachite era) Within a few weeks you could literally feed them out of your hand. Reddish fish poo had to be brushed through the drain daily. I don't know if the colour indicates partial digestion or not but I can say that the condition factor of the fish increased greatly. Egg survival remained the same for both fed and unfed fish but there was a reduction in fungus problems for fed fish. Because of the success of this experiment, not in egg survival but in fish health appearance we started feeding winter runs and cutthroat.

As for summer winter cross breeding  There wouldn't be summer winter fish if they cross bred in the wild.

Excellent info M   What stock?  And wouldn't it be great to have the resources today to do more of those experiments ..