2 new scorpion papers

Fig8Article 1

Graham, M.R., R.W. Bryson & B.R. Riddle. 2014. Late Pleistocene to Holocene distributional stasis in scorpions along the Baja California Peninsula. Biological Journal of the Linnean Society. Early View (LINK)

ABSTRACT: The biota of the Baja California peninsula (BCP) assembled in response to a complex history of Neogene tectonics and Quaternary climates. We constructed species distribution models (SDMs) for 13 scorpion species from the BCP to compare current suitable habitat with that at the latest glacial maximum about 21 000 years ago. Using these SDMs, we modelled climatic suitability in relation to latitude along the BCP. Our SDMs suggested that most BCP scorpion distributions have remained remarkably conserved across the latest glacial to interglacial climatic transformation. Three areas of climatic suitability coincide remarkably well with genetic discontinuities in other co-distributed taxa along the BCP, indicating that long-term persistence of zones of abrupt climatic transition offer a viable alternative, or synergistic enhancement, to hypotheses of trans-peninsular seaways as drivers of peninsular divergences.


Article 2

Webber, M.M. & M.R. Graham. 2013. An Arizona bark scorpion (Centruroides sculpturatus) found consuming a venomous prey item nearly twice its length. Western North American Naturalist, 73:530–532. LINK

ABSTRACT: Arizona bark scorpions (Centruroides sculpturatus Ewing) are commonly found throughout the Sonoran Desert in southwestern North America, and they are well known for being the most venomous scorpion in the United States. Despite their medical significance, C. sculpturatus remains ecologically understudied, and little is known regarding its natural foraging and feeding behaviors. Here, we present the first documented case of C. sculpturatus feeding on the Sonoran Desert centipede (Scolopendra polymorpha Wood) in the wild.

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The Sin City Scorpion

Pseudouroctonus peccatum - Male holotype (bottom) and female paratype (top).

Pseudouroctonus peccatum – Male holotype (bottom) and female paratype (top).

Congratulations to Amanda Tate and Rebecca Riddle for their first publication!  Both were students in my Invertebrate Zoology course at UNLV when they discovered an important new species of scorpion in the mountains just outside of Las Vegas, NV.  They named the scorpion Pseudouroctonus peccatum, as “peccatum” is Latin for “sin” in reference to the proximity of this species to Sin City (Las Vegas). We made several trips to the type locality but only found a handful of individuals, which explains why the species remained unknown to science for so long despite occurring in a popular tourist destination.  Hmm, how many other new scorpions have yet to be discovered in the mountains of the American Southwest?

Their discovery was recently published in the peer-reviewed, open-access journal ZooKeys. Amanda, Rebecca, and I all thank Michael Soleglad for his valuable contributions to the paper.

CITATION: Tate, A.E., R.R. Riddle, M.E. Soleglad & M.R. Graham. 2013. Pseudouroctonus peccatum, a new scorpion from the Spring Mountains near “Sin City,” Nevada (Scorpiones, Vaejovidae). ZooKeys, 364:29–45.

LINK: http://www.pensoft.net/journals/zookeys/article/6288/abstract/pseudouroctonus-peccatum-a-new-scorpion-from-the-spring-mountains-near-sin-city-nevada-scorpiones-vaejovidae

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Tityus grahami


Tityus grahami – male holotype

Well, after a busy year with lots of changes, I neglected to notice a new species of scorpion from the Upper Rio Negro region of the Brazilian Amazon with a brilliant name… Tityus grahami! Yup, my generous colleague Dr. Wilson Lourenço named the species after me for my “enthusiastic interest in the study of scorpions.” The paper was published in 2012 (citation & link below), but I had not been following the South American literature and only recently discovered the paper.

Tityus is a diverse genus distributed throughout most of South America, part of Central America, and the West Indies.  At least 10 of the more than 200 species are considered dangerously venomous.  I owe many thanks to Dr. Lourenço for this honor, as well as for providing the picture of the T. grahami holotype on the right.

Citation: Lourenco, W.R. 2012. Further considerations on Tityus (Archaeotityus) clathratus C. L. Koch, 1844 and description of two associated new species (Scorpiones, Buthidae). Boletin de la SEA, 50:277–283.

Link: http://www.scorpionworlds.fr/medias/files/tityus-clathratus.pdf




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New Position!

File:Eastern Connecticut State University.svg
I am excited to say that I have accepted a position as an Assistant Professor in the Department of Biology at Eastern Connecticut State University (known simply as ‘Eastern’).  The position begins in August of 2013, when I will start teaching Invertebrate Biology (BIO 336) and Organismal Biology (BIO 120) for the fall semester.  Eastern students interested in scorpions, centipedes, herpetofauna, systematics or biogeography are encouraged to contact me.  I am particularly interested in students that are eager to develop a combination of field and laboratory skills, and those that would be excited to conduct field work throughout the Appalachian Mountains and the deserts of North America.

Jessica and I, as well as our three dogs, look forward to our transition to beautiful New England.  I personally can’t wait to finally explore more of Appalachia, and to contribute to our understanding of the history of biodiversity in this ancient but under-appreciated region.


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Elevation of an Enigmatic Scorpion

Euscorpius croaticusColleagues and I just elevated Euscorpius germanus croaticus, a rare and taxonomically confusing scorpion from Croatia, to E. croaticus in the following publication.

Graham, M.R., M.M. Webber, G. Blagoev, N. Ivanova & V. Fet. 2012. Molecular and morphological evidence support the elevation of Euscorpius germanus croaticus Di Caporiacco, 1950 (Scorpiones: Euscorpiidae) to E. croaticus stat. nov., a rare species from Croatia. Revista Ibérica de Aracnologia, 21:41–50.

ABSTRACT: The taxonomic identity of Euscorpius germanus croaticus Di Caporiacco, 1950, described from Croatia and Bosnia, has remained unclear ever since its discovery. We studied the lectotype from the Velebit Mountains as well as new material from Biserujka Cave on Krk Island, Croatia. We reassessed E. g. croaticus using both morphology and DNA barcodes (cox1 sequences) from one of the Biserujka Cave specimens and 15 congeneric species. The resulting DNA phylogeny suggests that E. g. croaticus is not a subspecies of E. germanus. The taxon appears to be a separate lineage, which groups close to subgenus Alpiscorpius but differs from all its members in several morphological characters. We elevate E. g. croaticus to species rank as Euscorpius croaticus Di Caporiacco, 1950, stat. nov., and provide a detailed redescription of both sexes.

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Who wants to find a new species?!

Want to know a secret? There might be a new scorpion species lurking in the high elevations of the Cerbat Mountains of Arizona! While I would really like to discover this species myself, as it nears the end of the field season, I realize that I am just not going to have time this year to take another look.  Maybe you are up for the challenge?

Over the past 5 years or so, colleagues and I have continued to discover and document new species of tiny brown scorpions that we like to call LBJs, short for “Little Brown Jobs” (see Fig. 1 for an example).  Although tiny, LBJs are fascinating. They represent a group of scorpions called the Vaejovis vorhiesi group, almost all of which are restricted to high-elevation habitats, usually pine forests, throughout the Mogollon Rim and Sky Island regions of Arizona, New Mexico, and adjacent states in Mexico.

Recently, a very unique LBJ was discovered from the Hualapai Mountains in western Arizona (Sissom et al., 2012). Given the degree of isolation of mountain habitats in the Hualapai range, it was not surprising that they contained an endemic scorpion. But do other mountain ranges in western Arizona contain undiscovered species as well?

To test this hypothesis, I used computer models to see if other western Arizona mountain ranges contained climatic conditions predicted to be suitable for LBJs. One of these models is depicted in Figures 2 & 3. Blue represents areas with climates considered unsuitable, whereas red portrays areas where climate is predicted to be suitable. White represents climates that are somewhere in between. As you can see, the model predicts that the high elevations of the Cerbat Mountains contains suitable climate… but is the habitat suitable as well?

Earlier this year I made several trips to the Cerbat Mountains to assess the habitat and attempt to discover a new LBJ. There is a nice road up into the mountains from highway 95 on the western side, so I thought it was going to be easy. Unfortunately, this road just does not access ideal habitats.  It takes you up to some primitive campsites with excellent views, but the dominant vegetation is Pinyon Pine and Juniper.  LBJs tend to prefer Pondersa Pine Forests.

After looking through USGS data layers, I found that there are stands of Pondersa Pines in the Cerbats, the biggest of which appears to be in the highest elevations flanking Mount Tipton. Of course, there is no road to this forest, you have to hike. So I did.

The hike was brutal and required lots of bushwhacking. There is no water along the way, so you have to carry your own. After a long afternoon, I finally made it to the Pondersa Forest (Fig. 4), which looked ideal for LBJs (Fig. 5). During my visit, however, it was hot, so I ended up ditching most of my gear down below, including my blacklight. Obviously, I underestimated the hike. All I could do was rock flip in the Ponderosa Forest for a half hour before climbing back down, scorpionless, through the brush in the dark to my campsite at the trailhead (Fig. 6). I think, however, that if someone spent some time up there with a blacklight, they might have better luck.

Are you up for the challenge?! Let me know if you want to give it a try and I will provide you with coordinates for the trailhead, the hiking route, and the Ponderosa Forest.

Good luck!


Article Cited

Sissom, W.D., G.B. Hughes, R.W. Bryson & L. Prendini. 2012. The vorhiesi group of Vaejovis C.L. Koch, 1836 (Scorpiones: Vaejovidae) in Arizona, with description of a new species from the Hualapai Mountains. American Museum Novitiates, 3742: 1–19.

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Barcode Biogeography in the Mediterranean

Euscorpius sicanus

Although the use of DNA barcoding to identify species has been a highly contentious issue among biologists (for reasons I will not get into here), there is no doubt that the practice has led to valuable contributions to our understanding of the world’s biodiversity.  In a manuscript that was recently accepted for publication, Victor Fet, myself, and international collaborators Pavel Stoev (Bulgaria), Nesrine Akkari (Denmark), and Gergin Blagoev (Canada) provide yet another example of how DNA barcodes can be used for more than just identifying species.  Using DNA barcodes from Euscorpius species collected throughout the Mediterranean, we were able to investigate the controversial natural occurrence of Euscorpius sicanus (C.L. Koch) in North Africa (Tunisia).

In brief, our results suggest that North African E. sicanus, as predicted by Fet et al. (2003), most likely represent an isolated relict population and not a recent introduction to the region.  Excitingly, molecular clock estimates suggest that E. sicanus in North Africa have been isolated since the Zanclean Flood, a sudden refilling of the Mediterranean Sea after it had evaporated during the Messinian salinity crisis. The Zanclean Flood is thought to have filled the Mediterranean in 2 months to 2 years, which is incredibly rapid in terms of geologic time, so we propose that the flood could potentially be used as an incredibly precise geologic calibration for fine-tuning molecular clocks in the Mediterranean.Our manuscript is slated for publication in the next issue of Serket, the Arachnological Bulletin of the Middle East and North Africa.  Thank you to Jan Ove Rein of The Scorpion Files for permission to use his digital version of Koch’s stunning painting of E. sicanus from the 1830s.

Fet, V., Soleglad, M.E., Gantenbein, B., Vignoli, V., Salomone, N., Fet, E.V. & Schembri, P.J. 2003. New molecular and morphological data on the “Euscorpius carpathicus” species complex  (Scorpiones: Euscorpiidae) from Italy, Malta, and Greece justify the elevation of E. c. sicanus (C. L. Koch, 1837) to the species level. Revue suisse de Zoologie, 110(2): 355–379.

Graham, M.R., P. Stoev, N. Akkari, G. Blagoev & V. Fet. (in press) Euscorpius sicanus (Scorpiones: Euscorpiidae) from Tunisia: DNA barcoding confirms ancient disjunctions across the Mediterranean Sea. Serket.

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