Evolutionary Biologist and Nature Photographer

Archive for August, 2012

Peek-a-boo

I was out hiking the other day looking for harvestmen and spiders, but almost every large rock I turned yielded a salamander!  Here’s one of the little guys hiding in some leaves.

North Carolina Salamander

A salamander from western North Carolina

The above image is actually a stack of two photos to get the depth of field I wanted on the face of this salamander.


My, what big eyes you have!

During the arachnologist field trip to Toft Point in Wisconsin a couple weeks back, I was in the field collecting with opilionologist Jeff Shultz and arachnid photographer Joe Warfel.  Jeff collected Caddo pepperella, a rare species of harvestman.  Previously this species has only been collected in pitfall traps so this was the first time anyone has ever collected and photographed this species alive!  I thank Jeff and Joe for giving me a chance to photograph the specimen.

Caddo pepperella is a tiny litter dwelling harvestman that very few people will ever observe out in the wild!  The length of its body is less than ONE millimeter!!!  And its legs are not much longer than a couple millimeters.   But small as it is, relative to its body size, the eyes are huge!

Caddo pepperella (Caddidae), from Wisconsin

 

Caddo pepperella (Caddidae), from Wisconsin

Updated on 4/2/13 – species is Caddo pepperella, ID by J. Shultz.


Waterfalls of Glen Burney

Last Sunday, despite the gloomy weather forecast of 50% chance of rain all day, we decided to head out and hike the Glen Burney Trail along a small stream near Blowing Rock, NC.  Its a great little 3 mile hike that visits several different falls along the way.  I decided to get my feet wet, literally, to get some of these shots of the falls from various angles.

Glen Burney Falls along the Glen Burney Trail

Glen Burney Falls along the Glen Burney Trail

Glen Burney Falls along the Glen Burney Trail

Glen Marie Falls along the Glen Burney Trail

Glen Marie Falls along the Glen Burney Trail. I selectively removed all colors except green for an artistic effect. Original shown above.


The Harvestman with Horns

The ubiquitous species of harvestman Phalangium opilio was named by Carl Linnaeus in 1758.  P. opilio is now distributed all over North America, where it has been introduced from Europe (thankfully it is not a pest!).  The species range has also apparently spread into parts of Asia and Africa.  This species thrives in a number of different habitats, including natural habitats, such as forests, as well as anthropogenic habitats/structures, such as under bridges, in gardens or green spaces.

Males of P. opilio have large horns on their chelicerae (pointing outward, away from the anterior end).  These structures are used as weapons in male-male contests which most often results in the loser fleeing and the winner having a chance to mate with a nearby female.

Below are a few more photos from a field trip to Toft Point, WI during the 2012 meeting of the American Arachnological Society at UWGB.

Notes on image below: The cheliceral horns are the long pointed cones sticking off of the first pair of appendages (the chelicerae).  The chelicerae bend downward, each terminating in a movable, pincer-like claw that is not visible here.  Note that the male pedipalps are very long, unarmed, and appear as if they are an additional pair of legs (here the pedipalps are more gold in color, while the legs are black).  This male is also missing the second walking leg on the near side of the body.

Male Phalangium opilio Linnaeus 1758.

Image below: Same male, dors0lateral view.

Male Phalangium opilio Linnaeus 1758.

Image below: Female from a dorsal view.  The pedipalps are shorter and are held close to the body partially covering the smaller chelicerae of the female.

Female Phalangium opilio Linnaeus 1758 demonstrating the lack of cheliceral horns and smaller pedipalps.  Dorsal view.

Female Phalangium opilio Linnaeus 1758 demonstrating the lack of cheliceral horns and smaller pedipalps. Lateral view.

References:

Harvestmen: The Biology of Opiliones. 2007. R. Pinto-da-Rocha, G. Machado & G. Giribet (Eds.). Harvard University Press.

Willemart RH, Farine J-P, Peretti AV, Gnaspini P. 2006. Behavioral roles of the sexually dimorphic structures in the male harvestman, Phalangium opilio (Opiliones, Phalangiidae). Can. J. Zool. 84: 1763-1774.


Full Moon

I have a new found interest in astrophotography…lately I’ve been reading a lot about it.  I really enjoy photographing the night sky, however it is not an easy task!  I don’t have any great pictures of the stars just yet, but I’m working on it (when the weather cooperates).  So I thought I’d share a photo of the waxing gibbous moon from a few days ago and one of the full moon that was visible two nights ago.  I never invested in a telescope…but I’m adding it to the wish list now.

Waxing gibbous moon observed on 7/27/2012 from Boone, NC.  Shot at 135 mm and cropped.

Full moon observed on 8/1/2012 from Boone, NC. Shot at 135 mm and cropped.


Arachnologists Unite

At most academic meetings the arachnologists often get lumped into an entomology section.  Or they might find themselves mixed in with general invertebrates.  But not this time!  Two weeks ago, in Green Bay, Wisconsin, more than 100 arachnologists from all over the world met for the annual meeting of the American Arachnological Society hosted by University of Wisconsin at Green Bay.  The meeting took place over the course of four days and included all kinds of arachnid-based talks, posters, social events and an auction with all kinds of spider paraphernalia (books, t-shirts, toothbrushes, old photos, jewelry and more)!  It was a great opportunity for many enthusiastic arachnologists to share their exciting research regarding the charming little animals that strike fear into the hearts of most people!

After the official meeting concluded there was a field trip to visit Toft Point State Natural Area, on a peninsula along the western shore of Lake Michigan.  About 40 arachnologists jumped on a bus, headed up to Toft Point, and collected specimens in hopes of adding to the list of known arachnids from this site.  Here are a few spider photos from the field trip.

A small juvenile, female Dolomedes tenebrosus (Pisauridae).

This spider appears to have placed its egg sac into what’s left of this dead plant.

The always charismatic jumping spider, Phidippus sp. (Salticidae)