North American Tarantula, Brown Tarantula
Aphonopelma sp.
Theraphosidae (Tarantulas), Order Araneae
Physical Description
Robust, heavily-built body covered in dense setae (hair-like bristles) with clearly defined cephalothorax and oval abdomen. Shows characteristic tarantula proportions with stout legs.
Size Estimate
Body length approximately 3 to 5 cm with a leg span of 8 to 12 cm. This specimen appears to be a sub-adult or juvenile.
Coloration & Markings
Uniformly dark brown to blackish coloration overall, with lighter brownish or reddish setae covering the carapace and legs.
Web Type
Does not build traditional webs; utilizes silk primarily to line burrows, create egg sacs, or detect approaching prey via tripwires.
Eye Arrangement
Eight small eyes clustered closely together on a raised tubercle (ocular prominence) at the front-center of the cephalothorax.
Leg Characteristics
Thick, robust legs covered in dense setae, equipped with specialized claw tufts and scopulae for climbing smooth vertical surfaces.
Venom & Safety Information
Venom Information
Mild neurotoxic and proteolytic venom, generally causing localized pain and swelling in humans, comparable to a bee or wasp sting.
Medical Significance
Not medically significant to humans. Bites are rare and non-lethal, though urticating hairs kicked off the abdomen can cause skin and eye irritation.
Safety Recommendations
Avoid handling roughly to prevent defensive hair flicking or bites. If found indoors, gently guide into a container and release outside.
Habitat & Behavior
Habitat & Range
Found across the Americas, primarily in arid, semi-arid, desert, and grassland regions, dwelling in self-excavated or abandoned ground burrows.
Behavior & Temperament
Ground-dwelling ambush hunter, primarily nocturnal. Generally docile and slow-moving, preferring to flee or display threat postures rather than bite.
Diet & Prey
Primarily feeds on large insects, beetles, grasshoppers, and occasionally small reptiles or amphibians using venom-injecting chelicerae.
Seasonal Activity
Most active during warmer months, with mature males wandering widely during late summer and autumn looking for females.
Description
A classic North American tarantula, featuring a sturdy, hairy body and deliberate movements. Though often feared due to their size, they are gentle giants that play an essential role in controlling insect populations.
Key Features
Large, bulky, heavily setose body, stout legs, ground-dwelling habits, and clustering eyes on a distinct cephalothorax mound.
Similar Species
Wolf spiders (Lycosidae), though tarantulas are easily distinguished by their massive size, heavy hairiness, and forward-facing chelicerae.
Life Cycle
Females lay hundreds of eggs inside a silken egg sac. Spiderlings disperse after hatching. Molts frequently during growth, achieving lifespans of decades for females.
Ecological Importance
Acts as an apex invertebrate predator controlling insect and small arthropod populations, while serving as prey for birds and mammals.
Conservation Status
Not evaluated on the IUCN Red List, though localized populations face threats from habitat destruction and the pet trade.
Interesting Facts
Female tarantulas can live for over 25 years, whereas males typically die shortly after reaching maturity and seeking mates.
Photography Tips
Use natural lighting, shoot from a low angle parallel to the ground, and maintain a safe distance to avoid startling the spider.
Identified: 2026-09-25T20:49:30.643062