What kind of spider is this? It was photographed June 2, 2007 in San Isidro, TX (Starr County). This one was on a fence post eating a grasshopper. I have other photos that are higher resolution (about 2mb in size). I cropped and re-sized this one to insert into this email…
My first reply was that this was a male redbacked jumping spider (Phidippus johnsoni). However, within days I’d talked with the late Dr. Robert G. Breene III (a.k.a. Spider Bob, who passed away on 28 October 2009), about his project to standardize the common names of North American spiders. According to Dr. Breene, the common name for this spider, as accepted by the American Arachnological Society’s Common Names Committee–which Breene chaired–was the Johnson jumper, and that is the name I have used since.
After all, when we use a common name for a spider, we should try to be consistent. If the same spider is called a redback jumper by one person, a redbacked spider by another, and a Johnson jumper by yet another, only confusion can result. And anything that reduces confusion is good, right? Well, regardless, it should be noted that many if not most professional arachnologists, such as my good friend, Dr. Pierre Paquin, wax quite unenthusiastic about the idea of granting even semi-official status to the common names of our spiders.
Pierre, a Canadian, is one of the world’s foremost arachnologists. He co-authored the encyclopedic work “Spiders of North America,” (Ubick et al., 2005). On one spring day in 2010, he and I, along with his colleague, Kemble White, debated the relative merits of common names and taxonomical ones over a bowl of gumbo, a plate of fish, and a platter of Greek salad, at Gumbo’s Restaurant in Round Rock, Texas.
“The taxonomical name, Jerry…” Pierre gestured in the air with his fork. “That’s what we should be emphasizing.”
And viscerally, at least, I had to agree. In fact, I always mention the taxonomical along with the common name–if the latter exists–of any of the organisms posted here. Some organisms have no common names, but most have taxonomical ones. And yes, that fact does argue strongly in Dr. Paquin’s favor.
“The problem, Pierre,” I mused, spearing a ripe olive and chili pepper whilst putting on my best smiley face, “is that non-arachnologists, even serious scientists in other fields of biology who are not familiar with the taxonomic names of the spiders they encounter, find it more convenient to work with common, non-scientific names. Those are the names they use with their families, their co-workers, the people they discuss these things with. How can we expect them to use a different nomenclature to communicate with us?”
Pierre sampled another spoonful of gumbo, saying nothing.
“And, here’s the bottom line,“ I added, “Bugsinthenews exists to build bridges between the non-arachnologists who shy away from Latin names, and the experts in the field for whom taxonomical considerations reign supreme.“
Dr. White, with a PhD in geology, specializes in karst and the critters that inhabit such geological structures. No doubt he has strong feelings on this subject, too, but you would never guess by his outward expression. He glanced first at Pierre, then at me, his face inscrutable.
We’d been discussing a much more serious subject, that of the karst invertebrates, particularly a genus containing a few endangered–or not so endangered, depending on your point of view–blind, cave-dwelling spiders in the Dictynidae family (the Circurina) that Pierre and Kemble had been studying and surveying over the past several years in the caves of Central Texas. This sidebar on nomenclature was distracting. But it was half serious, too. I had always had a deep respect for the work that Dr. Breene had carried out as chair of the Common Names Committee, but I also knew that his work was controversial, and that it had been a source of much grief for him.
More than once, during our discussions, Breene asked if I would be willing to take the job. “I’d put in a good word for you with Dr. Edwards, at Florida State,” he told me. As if a layman like me would be a good pick for that work. No doubt he’d asked a lot of people that same question over the years. And, of course, like them I declined. A year or so later, when word of his death reached me, I realized how much the world of arachnology had lost by his demise…
Pierre mumbled something under his breath and half smiled, half frowned. Methinks by that stratagem we agreed to disagree. Friends can do that, especially on topics like this one, that deal with things that are anything but earth-shattering in their overall importance. I understood Pierre’s perspective. He gets to study his spiders under the microscope, examining the minutiae of their various anatomical structures–a minutiae that I rarely get to see. The photographs sent to me are enough to distinguish the obvious, but not much more. He, on the other hand, is able to dissect his specimens and peer into the deeper mysteries. And if that isn’t enough, he can have the specimen’s DNA analyzed to clinch the identification within a gnat’s eyebrow. But those are other stories, for another place and time.
Besides, the gumbo, at Gumbo’s, was excellent. Kemble had one of the fish entrees (also excellent), and I was eating a truly delectable Greek salad. Yeah, that was it for me. Having accepted my lot as a fleshaholic in need of recovery, I now eschew (almost) everything animal in favor of everything vegetable as long as it doesn’t have gluten.
And yes, we could all agree that it’s no way for a Texan to live. But I digress…
Back to Cat’s Johnson jumper…The photographs she sent were outstanding. However, because the face of this specimen was so dark, and–when taking the photos–Cat did not force a flash (which can bring out subtle features not discernible in an ordinary photo), it seemed advisable to work the photos over with imagery enhancement software.
I particularly wanted to see the large anterior median eyes (AME) , the eyebrow tufts, and the iridescent chelicerae that characterize most of the spiders in the genus Phidippus. Unfortunately, in the unretouched photos, none of those features was visible.
Adobe Photoshop Elements 7.0 could not bring out anything but the eyebrow tufts. Later on, when APsE 8.0 became available, the photos were processed again, and in those images (all those posted here have been reprocessed with APsE 8.0) the AME can be seen, along with a hint of greenish iridescence in the chelicerae.
If you click on the second photo in this post, its enlargement will pop up and you should be able to discern–just barely–two large eyes just above the spider’s jaws. They look like they are covered with fuzz, but that is an artefact of the image enhancement process. A later photo, below, which is an enlargement of the head taken from another of Cat’s photos, shows the eyes a bit more clearly. In none of these photos, however, do they show up as the glossy, headlamp eyes we are used to seeing in the jumping spiders. This specimen was simply too dark in the face.
By the way, as you examine the enlarged photo, you will likely wonder, at first, what I mean by saying you can see the eyes more clearly when, in fact, they are still almost entirely obscured by the blackness of the face. You have to look in the right place to see them, or you’ll miss them entirely.
Do the following and it may help: while looking at the photo below, on this page and unenlarged, notice the light-colored inverted “V” (its apex points upward, instead of down) where the jaws come together (the light-colored matter is probably debris from the spider’s last meal). Just above the inverted “V” is a faint, darkened, arc that circumscribes the lower margin of the spider’s lefthand AME. Now notice, above the inverted “V”, another light-colored, sort of side-ways “V” with its apex pointing to the 2 o’clock position. This is a lower eyebrow tuft, just above the spider’s lefthand ALE. The longer, highest arm of this “V” touches the upper edge of the spider’s lefthand AME. Now, look again at the spider’s jaws, and notice that the righthand jaw (from the spider’s perspective, of course) has a light-colored area at its upper righthand quadrant that extends about halfway across the upper margin of the jaw. Now draw a short imaginary line upward, from the midline of this jaw. That line intersects the lower margin of the spider’s righthand AME, approximately the same distance from the jaw that the lefthand AME is from the inverted “V”. Get a sense of the location of the eyes from that photo, then click on it to see the enlargement, and look for them there. Once you see them, they kind of “boom” in. But until that happens you may actually wonder if I’ve lost my mind.
Regardless, we can see enough to know this is, indeed, a Phidippus. And the fact that it has a black carapace and red dorsal abdomen suggests strongly that it is a Johnson jumper (Phidippus johnsoni). We have–however–other jumping spiders in North America with those features, too, so the identity of this specimen is not certain, and cannot be confirmed without examining, microscopically, the unique structures of the pedipalps, for a male, or the epigynum, for a female.
The female Johnson jumper does not usually have the all-red dorsal abdomen of the male. Quoting from B. J. Kaston, in his book “How to Know the Spiders,” (3rd Ed., 1978), p. 258: “The carapace is black in both sexes. In males the abdominal dorsum is all red, but in females, this is seldom the case; usually the red appears on either side of a median black band on the posterior two-thirds of the dorsum.”
In the illustration Kaston provides, the median black mark on the feminine abdominal dorsum is relatively broad, and faintly incised midway along its lateral periphery. The important thing to note here is that such a mark is absent in Cat’s specimen, which would suggest, but not clinch, the sex of this spider as male.
This species will bite humans if given the opportunity, but the bite is generally not serious. I told Cat that it would help if she sent the higher resolution images. She did so, and selected portions of those images are provided in this post.
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