Saturday, June 23, 2012

Subspecies slam?

Two subspecies of cutthroat trout are native to Montana: westslope and Yellowstone. I learned yesterday that the lake I fished has been stocked with both in the past decade and I think I caught both.

From the Montana Field Guide website:
"It can be difficult to visually distinguish westslope from other cutthroat trout subspecies, but the westslope cutthroat trout tends to have more small spots by the tail and none by the pectoral fin and the fish is more of a silvery or greenish color. The only way to be certain about identification of this subspecies is by genetic testing (AFS website 2003)."
And this:
"The Yellowstone cutthroat trout is visually distinguished ... from other cutthroat trout subspecies by its medium-large, black spots that tend to be concentrated posteriorly, and its drab brownish, yellowish, or silvery coloration, with brighter colors generally absent even in mature fish (Behnke 1992, Baxter and Stone 1995) (AFS website 2003). "
Being from the same lake with no other apparent influence, I'd say these two have to be different subspecies. What do you think?
And just for fun, some are huge in this lake:
 Even if I could get that guy to eat, I don't see how I'd have a shot at landing him. Therein is the fun.
Happy summer 2012!

5 comments:

Satoshi Yamamoto said...

I think I can distinguish Westslope to Yellowstone rather easily. As far as I can say from my catches & pictures, Westslope has pink belly with a few (almost no) spots on belly, while Yellowstone's belly is covered with some spots plus it's usually golden yellow. But this is solely my "visual" way. Others might say different. You know the cover drawing of Fishing Regulation for YNP shows good examples.....

Joshua Bergan said...

Thanks, Satoshi. So what do you think about the fish I caught Friday?

David McKenzie said...

Top fish looks to be a WS Cutty and the bottom a Fine Spotted. Nice fish regardless though. I wish I was in close range to some of those!

Satoshi Yamamoto said...

I'd like to see entire body pics but simply judging from colors and visions in my memory, I think top one is Yellowstone and bottom Westslope. It may be because of the way picture was taken and where they live (water ingredients/minerals might affect colors), but I don't think Westslope looks that much yellows/golden (top pic). And pink belly, which is also distinctively wide, is Westslope......

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