Key-making: Illustrating the Stone Centipedes of New England

by Joseph DeSisto

Have you been waiting on the edge of your seat for an identification key to the New England stone centipedes? Do you often find yourself up late at night, eagerly searching for recent articles in taxonomic journals, only to have your chilopodological hopes dashed?

Well, your wait is (nearly) over! This week I started illustrating a key to the stone centipedes of New England. A total of 18 species are represented, the product of more than a year of relentlessly identifying hundreds upon hundreds of museum specimens, but the key is finally coming! It will be ready to send off to a journal by the end of the semester.

It will be ready. It will be ready. It will be ready.

Fangs! Photo by Joseph DeSisto.

Fangs! Because, fangs! Photo by Joseph DeSisto.

Anyway, I spent today working on line drawings, and I’ve included a few outlines here — note that the images below are not the images that will appear in the key itself. Rather, these are preliminary outlines I have made to provide a template for the final illustrations. They still need a lot of work, including shading.

The outline of the photo from earlier looks like this:

The prosternum (with fangs!) of Bothropolys multidentatus, one of New England's largest and commonest stone centipedes. Illustration by Joseph DeSisto.

The prosternum (with fangs!) of Bothropolys multidentatus, one of New England’s largest and commonest stone centipedes. Illustration by Joseph DeSisto.

Not bad for a first go, huh? Actually it was my fourth or fifth go, but moving on …

How does this work? First, I use a fancy microscope and an extra-fancy image-stacking computer program to make nice clear images of a centipede feature like the one above. Then I print out that photograph, and use a micron pen to outline, directly on the picture, the drawing I want to create. When the photograph is sufficiently defiled by lines, scribbles crossing out lines, and more lines, I put the paper on a light box and copy my outline onto tracing paper.

Then I copy that onto another piece of tracing paper. And another. And another, until finally I have one that’s good enough to look at without cringing.

The centipede from earlier is Bothropolys multidentatus, a common and large centipede in New England. Below I’ve illustrated the pores on the coxae (basal segments) of the 14th pair of legs:

The 14th coxae, viewed from below, of Bothropolys multidentatus. Illustration by Joseph DeSisto.

The 14th coxae, viewed from below, of Bothropolys multidentatus. Illustration by Joseph DeSisto.

The last two illustrations, you may have noticed, are roughly symmetrical. Real specimens are hardly ever that perfect — to make the illustrations look a bit nicer, and fit better on the page, I traced one half first and then traced its mirror image. In other words, the outlines are symmetrical because each side of the line drawing actually shows the same side of the original specimen.

Here’s a special one. This sexy leg belongs to a male Nadabius aristeus, a common but smaller New England centipede. There are two important features I’m trying to show here. First, there are two claws, rather than just one, at the end of the leg. Second, the hairy crest on the tibia is unique to males the genus Nadabius.

One of the terminal legs of a male Nadabius aristeus. Illustration by Joseph DeSisto.

One of the terminal legs of a male Nadabius aristeus. The tarsus/foot is at the bottom. Illustration by Joseph DeSisto.

Female centipedes be like, damn!

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