Trout Naming

[rayfound]

Steve and Sasha got me started on this with the discussion about Mexican Trout.

OK, so I've always been a little confused about one thing: Why are Trout called Trout, and Salmon Salmon. When if we go by the Scientific classifications, the lines are drawn wrong in common language.

Pacific "Salmons" and Pacific "Trout" (Rainbows, Cutts, and Subspecies, plus Gila and Apache Trout, and several Asian species) are all part of the Oncorhynchus Genus , while Brown Trout and Atlantic Salmon are part of the Salmo Genus.

Now it seems to me that this indicates a closer relationship between, say a Chinook Salmon and a Rainbow Trout, than there is between a Rainbow trout and a brown Trout - yet the trouts are Trouts.

Likewise, virtually every book about Trout has to make the point that Brookies, Lakers, Bulls and Dollies aren't "True Trout", they're "Char" - ie: From the Salvelinus Genus. But there is no similar note about Browns and Rainbows not being from the Same Genus at all either!?!?

Interesting to me. Maybe to some of you too.

I hereby propose that next time someone posts a picture of a 25lb Chinook, we need to say "Nice Trout" and when flybob (or I) post a dink Brown, it shall be referred to as a Salmon...

Nice Salmon!

[darrin terry]

Dude, that's a nice, dark little brown TROUT you've got there. Sweet.

No really, nice fish.

[Sasha]

Yes you are right The problem with common names is that they can contribute too much confusion on accurate species identification. For example everyone knows what a Clown fish is right? Now there are many different species that get lumped into the “Clownfish” category but they are different species. An example of this is the Percula Clown fish (Amphiprion percula) is a different species than the Maroon Clownfish (Premnas biaculeatus), however because of their common names one might think that they are in the same species. The same seems to be the case for different “Trout” species; I have not had the opportunity to do any real in-depth studies on “Trout” yet, mostly due to the fact that I can not find a lot of in-depth scientific reports on them.

And that is a nice little Salmo trutta you have there

[darrin terry]

Mix things up further by looking at interbreeding of various 'trout'. Can rainbows and browns interbreed? I know they don't because 'bows spawn in the spring while browns are fall spawners. But browns and brookies can interbreed and actually do in the wild. Rarely happens but it does happen. The offspring are called tiger trout. So, what happens if you try and cross breed 'bows and browns or brookies? In a lab spawning times should not be an issue since milt (sperm) and eggs could be frozen and used when needed. Not saying someone should, just questioning whether they could. Is this a possible mix? I would assume the offspring, if any, would be sterile as are tiger trout.

How close is the relation between the various 'trout'?

Rainbows (including goldens)
Cutthroats
Apaches
Gilas
Browns
Brookies
Mackinaws
Arctic Char
Lennok
Taimen
etc.

Obviously, the first four on the above list are very closely related, as are the mexican trouts discussed elsewhere. But in a bigger picture, how close are they all?

[rayfound]

Mix things up further by looking at interbreeding of various 'trout'. Can rainbows and browns interbreed? I know they don't because 'bows spawn in the spring while browns are fall spawners. But browns and brookies can interbreed and actually do in the wild. Rarely happens but it does happen. The offspring are called tiger trout. So, what happens if you try and cross breed 'bows and browns or brookies? In a lab spawning times should not be an issue since milt (sperm) and eggs could be frozen and used when needed. Not saying someone should, just questioning whether they could. Is this a possible mix? I would assume the offspring, if any, would be sterile as are tiger trout.

How close is the relation between the various 'trout'?

Rainbows (including goldens)
Cutthroats
Apaches
Gilas
Browns
Brookies
Mackinaws
Arctic Char
Lennok
Taimen
etc.

Obviously, the first four on the above list are very closely related, as are the mexican trouts discussed elsewhere. But in a bigger picture, how close are they all?

These Will easily hybridize with each other In fact, Rainbow hybridization is a leading cause of population decline for all listed species here. (Fertile Hybrids)

Rainbows (including goldens)
Cutthroats
Apaches
Gilas


These will all easily hybridize. Splake are often Sterile. Arctic Char/Brookie hybrids are often fertile. Read in a magazine once that a Arctic Char/Brookie hybrid Male is almost indistinguishable from a large male brookie.

Brookies
Mackinaws (Lakers)
Arctic Char

Tiger Trout are an oddity, like a Mule, in that they are mis-matched chromosomally (is this a word?), and create sterile hybrids.

Lennok (never heard of), Taimen, Hutchen, etc... I don't know.

Also, what of the Pacific Salmon Varieties - could you have a coho-chinnook hybrid? Or a coho-Rainbow trout hybrid for that matter?

Ahhh.... the fun games we could play with a lab.

[darrin terry]

Yeah, games. But I don't advocate crossing them. Ones that occur naturally don't bother me, which tiger trout do happen in the wild in small numbers.

Lenok are a very cook looking trout native to Mongolia, Korea, Japan and possible some of the surrounding areas. Look a little like a brown, a little like a cutt and a little bit 'bow-ish.






They've some very cool and different looking char as well.

Yeah, I knew the rainbow related species or sub-species could all interbreed and produce viable, fertile offspring. Not sure about the offspring of bows-browns, bows-brookies.

I had assumed that the various char could interbreed at least somewhat successfully.

Fertile offspring suggests a pretty close genetic relationship, while healthy but sterile offspring suggests a close but not further separated relationship genetically. Obviously an inability to interbreed at all indicates an almost complete genetic separation.

[darrin terry]

Some info on Japanese trout and char:

http://www.amago.jp.lv/trout/trout12.html

http://www.amago.jp.lv/trout/trout22.html

http://www.amago.jp.lv/trout/trout32.html

http://www.amago.jp.lv/trout/trout42.html

http://www.amago.jp.lv/trout/amago2.html

http://www.amago.jp.lv/trout/iwana2.html

[rayfound]

Yeah, I knew the rainbow related species or sub-species could all interbreed and produce viable, fertile offspring. Not sure about the offspring of bows-browns, bows-brookies.

Fertile offspring suggests a pretty close genetic relationship, while healthy but sterile offspring suggests a close but not further separated relationship genetically. Obviously an inability to interbreed at all indicates an almost complete genetic separation.

I researched once before and could not identify a Brookie/Bow or Brown/Bow hybrid, I did find something. I still don't completely understand it, but its a Genetics Journal from Japan detailing just what the chromosomal modifications are in a Brookie-Rainbow hybrid. http://www.journalarchive.jst.go.jp/english/jnlabstract_en.php?cdjournal=ggs1921&cdvol=63&noissue=3&startpage=219

In terms of being close - yes, to hybridize, species need to be close in chromosome alignment. Just like a Horse+Donkey = Mule. Fertile hybrids indicates theya re VERY close (potentially even subspecies of the same species)

[darrin terry]

Definitely beyond the entry to genetics I studied in college, 14-15 years ago.

From what I remember, the ability to creat fertile offspring indicated a lack a speciation. In other words species is the same, and you are basically looking at a subspecies difference. This indicates the differences are due to geographic isolation, but not enough genetic changes have occured to creat a separate species.

Rainbow:
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Salmoniformes
Family: Salmonidae
Genus: Oncorhynchus
Species: O. mykiss

Cutthroat:
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Salmoniformes
Family: Salmonidae
Genus: Oncorhynchus
Species: O. clarki

golden:
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Salmoniformes
Family: Salmonidae
Genus: Oncorhynchus
Species: O. mykiss
Subspecies: O. m. aguabonita

brook trout:
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Salmoniformes
Family: Salmonidae
Genus: Salvelinus
Species: S. fontinalis

brown trout:
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Salmoniformes
Family: Salmonidae
Genus: Salmo
Species: S. trutta

Looking at the classification of cutts vs. 'bows you see that they are listed as different species. This is contrary to what I was taught in college biology. They can interbreed quite successfully producing fertile offspring. Moving to goldens, you see only a subspecies classification change. Whereas with browns and brookies the change occurs at the Genus level in the classification. Certainly seems like there is some confusion in all this, at least in respect to cutts and 'bows.

[Sasha]

Very interesting stuff guys. We should start a "Flyfishingaddicts" Trout study

[rayfound]

Definitely beyond the entry to genetics I studied in college, 14-15 years ago.

From what I remember, the ability to creat fertile offspring indicated a lack a speciation. In other words species is the same, and you are basically looking at a subspecies difference. This indicates the differences are due to geographic isolation, but not enough genetic changes have occured to creat a separate species.

I would agree with that. That is also my understanding.

Looking at the classification of cutts vs. 'bows you see that they are listed as different species. This is contrary to what I was taught in college biology. They can interbreed quite successfully producing fertile offspring. Moving to goldens, you see only a subspecies classification change. Whereas with browns and brookies the change occurs at the Genus level in the classification. Certainly seems like there is some confusion in all this, at least in respect to cutts and 'bows.

I also agree, and one could likely make the argument that the Cutts should be treated the same as goldens, ie: O. Mykiss Clarki.... but then there are so many cuttthroat species (none of which I have caught ).



But Back to the REAL ( ) issue - What makes a "Trout" a "Trout" and a "Salmon" a "Salmon"??


Oh, and just when you think you have it all figured out, someone does THIS:
http://notexactlyrocketscience.wordpress.com/2007/09/14/trout-with-salmon-parents-could-help-to-revive-endangered-fish-species/