...oops....

...I meant to say 'onto something'... :p

Can't remember where he mentioned it but he raised the question of adipose fin removal as possible/partial explanation for poor hactory fish return rates...I think most people missed it buried fifty pages in thread, but its worth asking again, maybe.

...is it possible that the adipose fin performs some vestige function we are unaware of?

Well, someone's gotta take the bait

Actually, I think it improves return, and here's why. Fish are reared en masse and counted by the pound. Nobody actually counts or looks at every fish unless they clip them. Then all of the pinheads, scoliated fish, those with fungus or other obvious defects or diseases are culled out - nobody wants to clip and release an obviously defective fish. So the result is you get real numbers of real healthy fish, instead of pounds of fish containing culls.

The reason hatchery returns of steelhead are getting worse is that hatchery steelhead are getting more inbred and unhealthy every year, that and predators are growing more babies on those abundant, stupid fish that are just made to be prey.

Hehe....

To be clear, in no way am I saying that I think there is a relationship between return rates and missing adipose fins, given what I know right this second.

However, if someone were to show that the adipose fin does perform some vestigal function, I'd be more inclined to.....gulp....take cfm's suggestion more seriously.

Its an interesting thought though. I've often wondered myself how we arrived at the idea that the adipose is 100% non-functional.