Fish Porn
- This topic has 12 replies, 8 voices, and was last updated Mar 28, 2008 at 1:00 pm by
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Tryin to learn how to post pics, this is one of my brother with a LL Salmon he caught last spring.
was about 22″ total.
DougBD –
That’s because landlocks are revisiting the same biological territory that created brown trout to begin with.
I don’t believe Zach stated that brown trout are native to North America. He stated “we don’t have native browns here” (meaning North America).
Greg
one would think sea run browns would have found there way over here at some point… Mysteries of fish..
BD –
That’s because landlocks are revisiting the same biological territory that created brown trout to begin with. Salmo trutta (browns) and Salmo salar (Atlantic salmon) shared a common ancestor a few million years back. The proto-Atlantics on the European side of the ocean sometimes got landlocked and became, over millenia, the brown trout. Those in the ocean and, for reasons I don’t understand, in North America, remained sea-runs and became Atlantic salmon.
I have never been able to pin down a biologist on why we don’t have native browns here. It’s probably a long enough time frame that the continents were in a somewhat different configuration, but the proto-Atlantics should still have lived in *an* Atlantic ocean with a North America and a Europe on each side. (In fact, there are browns high up in the mountains in Morocco in N. Africa that are native).
Somehow, conditions in Europe must have been ripe for proto-Atlantics to become stream-residents and evolve, but they weren’t right here. (Presence of chars which competed? I don’t know.)
Arguably, though, were humans to go away and quit messing up rivers, the landlocks we now have would eventually evolve into a North American brown-trout equivalent. They just took a lot longer to take up residence in streams.
Zach
I guess I think this is wrong.
Mike –
“The reason there are no browns is because browns DID NOT evolve from landlocked Atlantic salmon.
I think Gary is going to weigh in here, but it looks like Mike is largely correct.
Here’s a very dense biology text relating to the evolution of Atlantic salmon:
Basically what I glean from that is that brown trout and Atlantic salmon diverged from a common ancestor way further back than I thought – 4-5 Million years ago. In much more recent times, Atlantic salmon (which remained true to their roots and made longer voyages) migrated to and colonized North America. They didn’t do this in big waves though; they were dependent on things like lower sea levels extending Ireland to the west, etc. They probably also lived in areas that are now beneath the waves.
Based on genetic testing, it appears that Atlantics and landlocks are in some cases even more differentiated in one area than Atlantics from both sides of the ocean. I suspect that means that the isolated landlocks had more opportunity to go on diverging than the Atlantics that remained able to breed with other Atlantics.
At any rate, the answer to my question seems to be this: brown trout evolved out of the common ancestor with Atlantics *before* that common ancestor made its way to the New World. (In other words, Mike was exactly right when he said “Both species evolved from a common ancestor, as you stated.
I dont think we agree, or are saying the same things differently.
Now that Atlantics have become landlocked in North America, it makes sense that they would evolve into a brown trout analogue (meaning, our version of the brown trout). I am not saying the landlocks would become browns; they would just evolve to become a similar fish (really, they already have).
The problem is they haven’t evolved at all. Landlocks are genetically identical to Atlantic Salmon. Unlike brown trout they are not a seperate species. This, to me, indicates that the fish is a relative newcomer to this continent.
The main point I am trying to figure out is this: we know browns evolved in Europe. We know they co-evolved from an ancestor species of the Atlantic salmon and the brown trout. We know that ancestor species *did* run to North America in the form of Atlantic salmon. Why then, if the same ancestor species was visiting both continents, did Europe have conditions ideal to evolve brown trout, while North America did not? In other words, why don’t we have native brown trout on the Atlantic side of North America?
The ancestor species probably is not the species that made it to north america. The species that made it to north america was atlantic salmon, not ‘proto-atlantics’ or whatever. This is my contention.
Using your logic, the atlantic salmon that made it here would have to devolve into the ancestor species then reevolve back into brown trout.
EDIT:
Just saw your other post.
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