Odd place for a Dicamptodon

[josef]

I noticed this guy hanging out amid many of the more typical pond dwelling Taricha granulosa and Ambystoma gracile larvae. The ponds were in a mountain meadow and were fed by springs in the Columbia River Gorge of Oregon. Never thought I'd see a Dicamptodon on a pond lily.

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[kaysie]

Must have stopped in to pick up some lunch.

 

[nate]

Doesn't look much like a Dicamptodon larva to me...

Anyway, Dicamps are known to use ponds and lakes, especially at higher elevations.

 

[russ]

Not at all. Looks more like s Taricha about to morph.

RUSS

 

[nate]

Definitely

 

[josef]

If that looks like the tail of a Taricha to you guys then I must never haved seen one (Note that the end of the tail in the pic is the actual end of the tail, it doesn't taper AT ALL and is short, rounded and quite powerful). I could not handle it, but I could not see any orange on its belly. Furthermore, it would be a surprisingly large Taricha larvae, perhaps not out of the range of possibilities (I have 75 mm TL as the size maximum, and this was probably about that if not more). Also, the head shape is quite different, with a square snout and large, frontal eyes. Just out of curiosity, what makes you'll think that it's a Taricha? And you're right Nate, they are known to inhabit lakes and ponds at high elevations, it was just unexpected to me.

 

[nate]

Hi Josef, that animal is in the process of morphing and so many body parts (especially the head and tail) have not yet reached adult shapes/proportions. 2nd year granulosa larvae often reach 7cm+, not to mention neotenic juveniles.

I saved the image and played around with it in a photo editor to try and see it a little better. It lacks any pattern suggestive of a Dicamptodon, no hints of costal grooves, the eyes, the toes...I'd say it's Taricha.

 

[josef]

I assure you I have seen every stage of Taricha development from egg to adult. I've seen nearly every stage of Dicamptodon tenebrosus from 2" to 12" as well, in addition to several larval Dicamptodon copei, which this animal I photographed is actually in range for, but I don't believe is due to it's broader proportions. The tail is a dead give away, no matter what stage you look at in a Taricha, it always has a fairly long tapered tail, even more so in a larvae than in an adult. and Dicamptodons always have short, powerful, rounded tails; which this has. Coloration and patterning on Dicamptodon are, in my experience,weak to nonexistent in larvae of this size. Perhaps a higher res pic will help, as the one I posted is rather degraded.

Trust me on this one, on any given day I can find 25 Dicamptodon larvae of this size and bigger in my parents backyard, I know what they look like.

 

[nate]

Hi Josef, still looks like a 2nd year granulosa larva to me. I lived many years in the Pacific Northwest as well and have seen thousands of Dicamptodon and Taricha
in all stages. Tails, especially larval tails, are troublesome because they are often regrown or in some form of flux or regrowth and so aren't the most reliable characteristic at all. I think the lack of costal grooves, for example, is more important.

Take a look at these photos of D. ensatus:
http://elib.cs.berkeley.edu/cgi/img_query?enlarge=8030+3192+2808+0010

and

http://elib.cs.berkeley.edu/cgi/img_query?enlarge=0000+0000+0602+0220

Notice the pointed tail (not rounded as you say), the very high tail fin (which your animal lacks), and the obvious costal grooves (which your animal also lacks). I understand that you were there, not me, and so you would know better than I. However, if I were only going on that photo, I would definitely call it a Taricha.