Morphological difference between diploid and triploid rainbow trout

[wall3y3]

So I searched high and low on the internet for any info on this.  Pretty much everything I found says that diploids and triploids have no morphological difference.  Maybe I am up in the night but I feel like I could identify the difference visually by looking at the head and snout.  Triploids seem to have a small head and stubby snout that just looks a bit off.  What do you think?

[Cowboypirate]

I have trouble recognizing myself in the mirror, so I am no help at all to your question. Will see if any of our troutologist want to chime in.

[Anglinarcher]

Or the fact that small heads are often the result of fast growth, and triploids grow much faster.

[richyd4u]

Or the fact that small heads are often the result of fast growth, and triploids grow much faster.

Bingo...the faster growth rate I feel makes the bodies outgrow the heads on triploids, giving them the smaller head appearance.

[wall3y3]

Or the fact that small heads are often the result of fast growth, and triploids grow much faster.

That could be it.  I really think if you were to show me 10 rainbows some being diploid and some being triploid I could pick which is which.  Like I said every reference I could find say they are the same but I think they are visually distingushable.

[wormandbobber]

That could be it.  I really think if you were to show me 10 rainbows some being diploid and some being triploid I could pick which is which.  Like I said every reference I could find say they are the same but I think they are visually distingushable.

Ok Test...diploid or triploid?

[PBH]

wormandbobber: that was just plain mean!

[Kent]

Ok Test...diploid or triploid?

Yes

[Riverdogs]

wormandbobber:  that was just plain mean!

I got a kick out of him calling their bluff. Unfortunately many people are very susceptible and they can imagine all sorts of things. The data I've seen is that triploids don't typically grow faster than diploids in the same body of water. Sure I've caught some nice football triploids. But I only knew they were triploids because no diploids were present.

---

That could be it.  I really think if you were to show me 10 rainbows some being diploid and some being triploid I could pick which is which.  Like I said every reference I could find say they are the same but I think they are visually distingushable.

Ok Test...diploid or triploid?

You know that's not fair! But I'll take you up anyways.. Diploid, Diploid, Diploid, Triploid, Triploid, Triploid, Triploid.
I did this test with my son and nephew who thought they could determine white from orange Cheez-its by taste. My son thought the orange tasted better and my nephew thought the white tasted better. Blindfolded my son was right of 4 of 8. My nephew only got 3 of 8 right.
Hopefully I do better than 50/50.

[wormandbobber]

You were more like your kids--2 out of 7! But, thanks for playing!

Also, FWIW, had I been put to the same test, I would probably scored just as low or lower.

Some good reading on diploid and triploid trout performance:
https://collaboration.idfg.idaho.gov/Fis...rvoirs.pdf

https://www.rmpc.org//files/nwfcc/2009/1...Koenig.pdf

https://wildlife.utah.gov/pdf/fes/pdf/volume_12-2.pdf