D. tenebrosus vs D. copei

Heh, no this is not a smackdown match between the two species. I just have a close-up of the head/upper body areas of a larva of each. Unfortunately, the size difference is great enough (the copei is about 1.5X the size of the tenebrosus) that some of the features are not as noticeable. Also, I have had my micro lens and extension rings for less than 2 weeks and am still learning how to get good results.
First the tenebrosus:

The gills are somewhat longer than in copei, but this specimen is not a posterchild for this! lol Notice that the head is somewhat "streamlined" with the body. Also, the lighter markings on the body tend to run together almost forming streaks. The eyes are a little lower down than on the copei as well.

Now the copei.

This is actually a much better angle to see the biggest difference between the two species. There is a very noticeable "waist" between the head and body. The head is more squared off and the eyes are higher up on the head. The filament to stalk ratio for the gills is also somewhat smaller than for the tenebrosus. Finally, the light markings are more discrete patches than in the tenebrosus.

[JonathanH]

Wow - Dicamptodon posts really don't get much in the way of responses!

I made a flickr album of some of the larval giants I've seen this month. Some are copei, some are tenebrosus, and some I really am not sure about. Could you (or any other interested readers) take a look and tell me what you think?

Dicamptodon - a set on Flickr

[Kaysie]

Well, this thread is over 5 years old. Most people don't dig that far back into the archives!

[Kaiseric]

Great pics John. Dicamptodon has always been on my wish-list species but I'm on the east coast. . :P

[JonathanH]

Originally Posted by Kaysie

Well, this thread is over 5 years old. Most people don't dig that far back into the archives!

heh - yah, I only found it because it was the only post showing D. copei. I was surprised that it hadn't gotten a single response, even back when it was first posted.


Linus - thanks for the props! I love Dicamptodon and finding an adult was always a childhood dream. I've been in Oregon/Washington for the last month and have been finding a large number: 8 that I believe were D. copei (including one neotenic adult), and 23 that I believe were D. tenebrosus (including 6 transformed individuals, 2 of which were big adults).

[JonathanH]

So, no one coming through with the ID help?

[John Clare]

I've just taken a look. To my eye it's a **** shoot - I wouldn't want to bet on any sold ID. Great photos though!

[Lisa 8]

More indicative of species in early larval stages is the body length and head width. The legs of copei will not adpress while tenebrosus has a shorter body and more broad head. The legs usually adpress.