Tuesday, August 2, 2011

Snaketail Emergence Sequence

A while back I posted a sequence of shots of an emerging American Emerald (Cordulia shurtleffii) which was quite popular. You can see that post here. I love emergence sequences, so here’s another one—this time a female Pale Snaketail (Ophiogomphus severus) in the family Gomphidae, or the clubtails. This was on the Burnt River in eastern Oregon a few weeks ago. Just like last time, I included the time stamp in the upper right corner (hh:mm:ss), so you can see how much time elapsed between each shot.



As usual, emergence was already well underway by the time I could take my first shot in the sequence. Unlike many other dragonflies, clubtails are able to emerge on a horizontal surface and they look kind of odd with only the abdomen still in the exuvia. In this position, I find it suggestive of a cobra rearing up and spreading its hood which seems rather appropriate for something called a snaketail. The white thread is a tracheal lining which stays attached to the exuvia so that it is pulled out of a spiracle (an opening to the tracheal network) during emergence. This allows her to get oxygen from the air now that she is out of the water.

While my attention was elsewhere for a couple of minutes, the abdomen was pulled entirely from the exuvia and she is supporting herself entirely on her legs now. Wing expansion is progressing rapidly.




The wings are pretty much at their full length now, but the abdomen still has some stretching to do.

Now the wings and abdomen are at full, or nearly full length, and the wings are almost totally clear.

My attention was elsewhere again for a few minutes and all that's left is the exuvia which I collected for the record.

5 comments:

  1. Amazing photos! What lens did you use?

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  2. @Texas Susan Thanks, Texas Susan! For nearly all of my odonate photography, I use a 180 mm macro with a 1.4x tele.

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  3. What can I say? Another great series! And it's beautiful creature.

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  4. Wonderful sequence! ..... and I've always wondered about those white hairs.

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  5. Wow! Don't often see dragonfly emergence pictures. The green makes this one especially eye-catching.

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