Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[bentrod]

Washington State has record of a resident rainbow population, separate from saltwater by a physical barrier for more than 90 years, smolting and becoming anadromous.  The barrier was removed and a few years after the barrier was gone, they took off to see what jellyfish look like.  I'm not sure how many went out, but TMK, it was roughly 40%.  So....with that said, even genetics testing will not guarantee that once a resident, always a resident. 

[Rodney]

That's not surprising if one hypothesizes that staying small and feeding in the river, or smoltification to grow big in the ocean are different life strategies of a fish species (rainbow trout). Perhaps steelhead offsprings choose to residualize if conditions for smoltification are not ideal (water level, abundance of food to reach size of smoltification, geographical barrier, predation), so their survival is ensured. Perhaps generations later, offsprings of rainbow trout decide to smoltify and become steelhead again. It is a fascinating subject in my opinion, perfet as a thesis for some graduate student if it is not done already. One might even want to stretch it by suggesting resident coastal rainbow trout are jacks of steelhead, since they are predominantly male. It'd be interesting to find out if there are interbreeding happening between resident rainbow and steelhead.

In Europe, large sea trout (searun brown trout) are mostly female (5 to 20lb) while resident brown trout in creeks are mostly male (<5lb). The two populations interbreed.

Washington State has record of a resident rainbow population, separate from saltwater by a physical barrier for more than 90 years, smolting and becoming anadromous.  The barrier was removed and a few years after the barrier was gone, they took off to see what jellyfish look like.  I'm not sure how many went out, but TMK, it was roughly 40%.  So....with that said, even genetics testing will not guarantee that once a resident, always a resident. 

The same relationship has been seen in the last couple of years with Coquitlam River's kokanee and sockeye salmon.