Posts Tagged ‘odontomachus’

Here’s something new. Instead of trawling youtube to find the Sunday Night Movie, I’ve made my own. Click above to watch the compressed version, or if you have a speedy connection click here to see it in full HD glory.

I spent the afternoon experimenting with the video capabilities of the new Canon EOS 7d. The 7d is the newest camera in Canon’s SLR lineup, and unlike earlier models it can shoot high-definition video as well as stills.

I’ve been very curious to see how the video performs with my macro lenses. A lab colony of Odontomachus chelifer trap-jaw ants at the University proved patient and willing subjects for my first experiment. These ants have absolutely fascinating mandibles, they are held open like a bear trap and snap shut on a hair trigger.

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Odontomachus meinerti trap-jaw ant, Argentina

One perk of being at a research university is the opportunity to shoot the various study organisms on campus.  These subjects are interesting– they have to be, or they wouldn’t be studied- and when the research goes public I get the chance to disseminate my photographs with the science media outlets that cover the story.

Among my favorite campus animals is the Odontomachus trap-jaw ant, one of the focal taxa in Andy Suarez’s lab.  The researchers are looking at the biomechanics of the jaw, one of the fastest recorded appendages among all animals, and how it evolves to suit the differing ecology of the dozens of species in the group.  One of Andy’s students works on the structure of the mandible itself, recording where the chitin is the hardest, thickest, and heaviest.  I thought it’d be useful to have an image that really draws attention to just the mandibles, and not the ant attached to them.

This is a different sort of image than my usual fare.  Most macro work takes place at the small apertures of f/11 to f/18 or so.  These settings are pretty standard for insect photography, as they extend the depth of field and bring more of the insect into focus.  But every now and then I have reason to go the other direction.  Here, I opened the aperture to f/5.6, bringing the mandibles into very sharp detail while the rest of the ant blurs away. Perfect for an illustration of  the dense chitin along the jaws’ leading edge.

Oh, and here’s a shot of the whole animal, at f/13:

Odontomachus meinerti, Argentina

Odontomachus meinerti, Argentina

photo details (both images): Canon MP-E 65mm 1-5x macro lens on a Canon EOS 20D
ISO 100, 1/250 sec, twin flash diffused through tracing paper

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I’m on a roll!  Myrmecos.net has a new series covering several species of trap-jaw ants:

Go see!

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Odontomachus coquereli – Madagascar

Myrmecology continues to lead the way in online taxonomy. Today saw the release of the very first taxonomic paper published by the top-tier open access science journal, PLoS One.

Brian Fisher and Alex Smith combine alpha taxonomy with DNA barcoding to produce a revision of the Malagasy trap-jaw ants. The revision includes mitochondrial DNA sequences from some 500 individual ants and resulted in the inference of several new species. I’ve got plenty to say about DNA barcoding, but I’ll leave that for a later post and instead point you to the thoughtful commentary by Kevin over at The Other 95%.

The citation and abstract for the Fisher & Smith paper are below. (more…)

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