Scorpion du Jour
Hadrurus
arizonensis (Ewing, 1928)
- Today's subject is Hadrurus arizonensis (Ewing, 1928).
The generic name, Hadrurus, is from the Greek words hadr-,
meaning "thick," and ur, meaning "tail." The
specific name, arizonensis, is a place name meaning "of,
or belonging to," (-ensis) the state of Arizona, U.S.A.
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Vital Stats:
Systematics:
- This scorpion is in the family Iuridae and
belongs to the subfamily Hadrurinae. Currently recognized subspecies
include: Hadrurus arizonensis arizonensis Ewing, 1928, Hadrurus
arizonensis pallidus Williams, 1970, and Hadrurus arizonensis
austrinus Williams, 1970. This scorpion exhibits a variety of different
forms and color morphs and almost certainly represents a cryptic species
complex. Don't forget to check out the high resolution JPEGs for Hadrurus
arizonensis arizonensis and Hadrurus
arizonensis pallidus.
Original Description: Ewing, H.E. 1928.
- The scorpions of the western part of the United States, with notes
on those occurring in northern Mexico. Proceedings of the U.S.
National Museum, 73:1-24.
Distribution:
- Hadrurus arizonensis is found in extreme southern Utah and
Nevada, southern California, and western Arizona in the United States.
It is also found in northeastern Baja California and northwestern Sonora
in Mexico. Hadrurus arizonensis is generally restricted to desert
vallies throughout its range. Like many of the desert scorpions, it is
an obligate burrower. During the summer, however, individuals may be
found under rocks, logs, sleeping bags, and other surface objects.
Fun Facts:
- Members of the genusHadrurus are the largest scorpions found
in North America. Though defensive when first encountered, I have found
them to be among the easiest scorpions to handle both in the field and
in the lab. The venom of these large scorpions is not considered to be
particularly potent, but they can do considerable damage if improperly
handled. As always, certain human individuals may be allergic to the
venom and can experience life threatening side effects when stung (as
occurs with bee stings). Did you ever wonder why so many scorpions have
a dark crescent running from one set of lateral eyes through the median
eys and over to the opposite set of lateral eyes? (It keeps me awake
at night!) My best guess is that the coloration provides camouflage for
the animal as it sits at the opening of its burrow. See, the opening
of a scorpion burrow is semi-circular or crescentic in shape. At dusk,
the scorpion creeps up to the burrow opening and positions his carapace so
that the interface between the fading sunlight and the shadow of the
burrow falls directly across both lateral eye groups. Thus, the light
part of the carapace (directly
in front of the dark crescent) is in the light (but it blends in with
the desert sand) while the dark crescent and the rest of the body is
in the shadow of the burrow. As a result, there is no break in the light/shadow
interface. As the light fades, and the shadows lengthen, the scorpion
moves further out of the burrow.
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- Disclaimer: The views expressed here are mine
alone and do not represent the views of the Department of the Army
or the Smithsonian Institution... or anybody else for that matter.
- Dr. Scott A. Stockwell
