Aphonopelma chalcodes
Chamberlin, 1940
Desert Blonde Tarantula, Arizona Blonde Tarantula, Western Desert Tarantula, Mexican Blonde Tarantula
Aphonopelma chalcodes is a large-bodied burrowing tarantula native to the Sonoran and Chihuahuan deserts of the southwestern United States and adjacent Mexico. The exhibits pronounced : females are uniformly tan with a pale, densely hairy that gives the "blonde" , while males have black legs, -colored , and reddish . Females are sedentary, occupying deep burrows for their entire lives, whereas mature males abandon their burrows to wander in search of mates during summer monsoon season. The species is notable for its longevity, with females living 24–30 years and males 5–10 years, and for its popularity in the pet trade due to docile temperament and relatively low venom .
Pronunciation
How to pronounce Aphonopelma chalcodes: /æfənəˈpɛlmə ˈkælkəʊdiːz/
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Identification
Distinguished from other Aphonopelma by the combination of pale blonde contrasting with dark legs and in females, and the male's black legs with and reddish abdomen. The "blonde" carapace is particularly distinctive among southwestern tarantulas. Mature males can be recognized by tibial spurs on front legs and more slender build with smaller abdomen relative to leg length. Burrows with silk-strand-covered entrances in desert are characteristic. Similar species Aphonopelma hentzi and Aphonopelma anax differ in coloration patterns and geographic distribution; precise identification often requires examination of genitalia due to primitive genitalic structures in the .
Images
Appearance
Large-bodied spider with body length up to 56 mm in females and 44 mm in males; leg span approximately 8–13 cm. densely covered in pale tan or blonde hairs, contrasting sharply with dark legs and in females. Males distinguished by entirely black legs, -colored , and reddish abdomen. Both sexes possess on the abdomen—short, barbed defensive hairs that can be kicked off when threatened. Mature males have a spur on the underside of the front tibiae used to hold female fangs during mating. and typical of mygalomorph spiders.
Habitat
Occupies desert and semi-arid grassland , specifically the Sonoran and Chihuahuan deserts. Creates deep burrows in sandy or loamy soil, often under stones or in isolated locations; burrow diameter 25–51 mm with silk strands across entrance. Burrows extend deep enough to buffer against temperature extremes. Occupied burrows marked by thin silk curtain during daytime. characterized by sparse vegetation including creosote bush, mesquite, acacia, and various desert scrub plants. Elevation range from low desert flats to moderate elevations in associated mountain ranges.
Distribution
Southwestern United States and adjacent northern Mexico. Primary range includes Arizona (common and widespread), New Mexico, and extreme southeastern California. Extends into Sonora and Chihuahua, Mexico. Distribution limited to desert regions but can be locally abundant within this restricted range. Records concentrated in the Sonoran Desert proper and transitional zones into the Chihuahuan Desert.
Seasonality
activity peaks during summer monsoon season (July–September), when mature males wander in search of females. Females remain in burrows year-round but sit at burrow entrance at night when temperatures are favorable (23–31°C). Molting occurs primarily in March and April, though not strictly restricted to these months. Winter dormancy with burrows plugged by soil. Not strictly but predominantly active at night; occasionally seen at burrow entrance during early morning hours.
Diet
; feeds on insects and other small arthropods. Ambush that waits at burrow entrance for prey to come within striking range. Prey items include beetles, grasshoppers, crickets, and other ground-dwelling . Observed prey in field includes various insects attracted to desert vegetation. In captivity, accepts crickets, , and .
Life Cycle
Sexual maturity reached after minimum 7 years in optimal captive conditions; likely longer in wild. Molting occurs throughout life, including after sexual maturity—unusual among spiders. Documented molting sequence comprises 10 primary stages with 25 over approximately 2 years in individuals. involves male deposition of sperm in palpal bulbs, transfer to female spermatheca. Female produces sac containing average 600 eggs with gestation period 6–7 weeks. Spiderlings initially resemble females; males develop secondary sexual characteristics after several years. Females can live 24–30 years; males 5–10 years, with male death typically following successful mating.
Behavior
Sedentary burrow-dwelling lifestyle for females; males become nomadic upon maturity. Constructs and maintains silk-lined burrow with debris-plugged entrance during inactive periods. Defensive includes raising forelegs and , stridulation, and kicking from rather than biting. Urticating hairs cause irritation to mucous and skin in humans, particularly those with sensitivities. ambush ; detects prey through vibrations transmitted via silk strands at burrow entrance. Males wander extensively during breeding season, often crossing roads and open ground. Not aggressive; generally docile when handled, though individual temperament varies.
Ecological Role
Apex in desert ; regulates of ground-dwelling insects and other arthropods. Burrowing activity contributes to soil aeration and mixing. Serves as prey for tarantula hawk (Pepsis and Hemipepsis ), which are specialized ; also preyed upon by coatimundi, birds, and reptiles. may serve anti- function in addition to predator defense. Long-lived, stable populations indicate importance as persistent ecosystem component in desert .
Human Relevance
Popular in pet trade due to docile nature, longevity, and manageable size. Considered suitable for beginner tarantula keepers. Venom low relative to other theraphosids, with bite comparable to sting in severity. can cause allergic reactions in sensitive individuals; shed also capable of provoking reactions. Cultural icon of Sonoran Desert, frequently depicted in media representations of American Southwest. Subject of ecological and physiological research including visual system studies and venom biochemistry. Occasionally encountered by humans when males wander during monsoon season, sometimes causing alarm despite harmless nature.
Similar Taxa
- Aphonopelma hentziOverlaps in distribution (Colorado, New Mexico); darker overall coloration without distinctive blonde ; males lack and red coloration of A. chalcodes
- Aphonopelma anaxTexas and adjacent regions; larger size; different color pattern with less pronounced in coloration
- Aphonopelma moderatumSmaller with different preferences; less contrasting coloration between and legs
More Details
Venom Composition
Venom contains two characterized compounds, Apc600 and Apc728, which include spermine and 1,3-diaminopropane; these are theorized to function in short-term paralysis of prey but have not been extensively studied. Venom not considered medically significant to humans.
Visual System
Possesses two sets of (primary and secondary) with spectral sensitivity range 350–640 nm, peak sensitivity near 500 nm. Secondary eyes equipped with tapeta for enhanced low-light detection. Visual system adapted for and activity patterns.
Serum Biochemistry
Multiple lectins detected in with demonstrated binding capacity to sialic acid; functional significance unknown and requires further investigation.