Hadrurus anzaborrego

Soleglad, Fet & Lowe, 2011

Anza-Borrego Hairy Scorpion

Hadrurus anzaborrego is a large to the western Colorado Desert of southern California and extreme northern Baja California. It is a medium-sized member of the Hadrurus, reaching up to 11 cm in length. The exhibits two distinct color phenotypes: light individuals are pale yellow, while dark individuals have a melanic and mesosoma. Both forms display a characteristic dark, v-shaped pattern near the . The species name derives from Anza-Borrego Desert State Park, where the was collected.

Pronunciation

How to pronounce Hadrurus anzaborrego: /hædˈruːrəs ˌænzəˈbɔːrɛɡoʊ/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Hadrurus anzaborrego can be distinguished from the sympatric Hadrurus arizonensis by its preference for coarser sand and rockier microhabitats. The two color phenotypes (pale yellow versus melanic and mesosoma) are both marked by a dark v-shaped pattern near the . At 11 cm maximum length, it is smaller than H. arizonensis, which exceeds six inches (approximately 15 cm). Sex determination requires examination of the pectines: females have shorter pectines set further apart, while males possess longer pectines positioned closer together.

Habitat

Coarse sandy soils and rocky sites in desert environments. Occurs at elevations from 163 m to 915 m. Prefers coarser sand and rockier substrates than Hadrurus arizonensis where the two are sympatric near Borrego Springs, California.

Distribution

to the western Colorado Desert. Range extends from Joshua Tree National Park south to the eastern Sierra de Juárez in extreme northern Baja California, Mexico. The was collected at Anza-Borrego Desert State Park, California.

Diet

. Prey includes insects (crickets, , ants, pill bugs), spiders, and other small animals. Prey capture involves use of to grasp victims, followed by systematic stinging to administer venom.

Behavior

. By day, occupies subterranean galleries excavated in soil or beneath rocky overhangs and wood. These burrows may extend up to eight feet in length. At night, hunts on the desert floor using pectines and leg sensors to detect vibrations and odors from prey. Prey capture involves grasping with followed by systematic stinging. Defensive stinging occurs when threatened. contains a hyaline layer that fluoresces under ultraviolet light.

Ecological Role

in desert . Subterranean burrowing contributes to soil turnover.

Human Relevance

Venom is less toxic than that of many other scorpions; published LD50 is 198 mg venom/kg mouse body weight, approximately 30 times less potent than honeybee venom. Sting used for defense; handling should be avoided. Popular in educational petting zoo displays due to docile temperament when properly managed.

Similar Taxa

Hadrurus arizonensisLarger size (exceeds 15 cm), prefers finer sandy soils, sympatric near Borrego Springs, CA
Aptostichus anzaborregoTrapdoor spider sharing the epithet and Anza-Borrego Desert range, but belongs to entirely different order (Araneae)