Brazilian Wandering Spider, Banana Spider
Phoneutria nigriventer
Ctenidae (Wandering Spiders), Order Araneae
Physical Description
Large, robust body with a dense covering of fine, velvety hairs. It features a distinct dark longitudinal line on the cephalothorax and prominent, reddish-orange hairs covering the chelicerae, which serve as a stark warning signal when threatened.
Size Estimate
Body length ranges from 17 to 50 mm, with an impressive leg span reaching up to 130 to 150 mm. This specimen appears to be a mature adult.
Coloration & Markings
Predominantly grayish-brown to dark brown, often with faint light spots or stripes on the abdomen and characteristic bright red or orange hairs on the mouthparts.
Web Type
None. These are active hunting spiders that do not spin webs to catch prey, instead roaming the forest floor or vegetation at night.
Eye Arrangement
Eight eyes arranged in three distinct rows (2-4-2), with the middle eyes of the front and middle rows being notably larger, providing exceptional night vision.
Leg Characteristics
Long, powerful legs covered in spines, held in a characteristic spread-eagled defensive posture when provoked, often lifting the front body and legs upward.
Venom & Safety Information
Venom Information
Contains a potent neurotoxic venom (specifically PhTx3) that affects ion channels and causes intense pain, inflammation, tachycardia, and priapism in humans.
Medical Significance
Medically significant and potentially dangerous to humans. A bite can cause severe pain, systemic symptoms, and requires immediate medical evaluation and antivenom in severe cases.
Safety Recommendations
Never handle without professional training. Check boots and clothing when camping in its range. If bitten, seek immediate medical attention and keep calm.
Habitat & Behavior
Habitat & Range
Native to South America, particularly Brazil, northern Argentina, Paraguay, and Uruguay. Found primarily in tropical rainforests, hiding under fallen logs, beneath loose bark, and sometimes in banana plantations.
Behavior & Temperament
Aggressive and highly defensive when cornered or disturbed. Nocturnal hunters that actively wander in search of prey rather than waiting in a retreat.
Diet & Prey
Insects, large arthropods, small reptiles, amphibians, and mice, subdued quickly with potent neurotoxic venom.
Seasonal Activity
Active year-round in tropical regions, with peak wandering and mating activity increasing during the warmer, rainy months.
Description
The Brazilian Wandering Spider is one of the most formidable and famous arachnids in the world. Known for its nocturnal roaming habits and potent defense display, it stands tall on its rear legs, flashing bright red chelicerae to warn potential threats. While formidable, it plays a vital predatory role in its native South American ecosystems.
Key Features
Bright red/orange hairs on the chelicerae, large robust body, distinct defensive rearing posture with front legs raised, and wandering hunting lifestyle.
Similar Species
Wolf spiders (Lycosidae) and nursery web spiders (Pisauridae), which lack the distinctive bright red mouthparts and typically flee rather than rearing up aggressively.
Life Cycle
Females produce large egg sacs containing hundreds of eggs, guarding them fiercely. Spiderlings disperse via ground movement and ballooning. Lifespan is typically 1 to 2 years.
Ecological Importance
Acts as an apex invertebrate predator, helping to regulate populations of insects, rodents, and other small animals within its forest ecosystem.
Conservation Status
Not evaluated by the IUCN, but populations face local declines due to deforestation and agricultural clearing.
Interesting Facts
Ranked in the Guinness Book of World Records as one of the most venomous spiders; its venom has been studied for pharmaceutical applications, including treatments for erectile dysfunction.
Photography Tips
Exercise extreme caution and maintain a safe distance using a telephoto or macro lens. Avoid provoking the spider to prevent defensive strikes.
Identified: 2026-08-07T15:27:16.173427