Acanthoscurria musculosa
Black Velvet Rump - complete care guide
Black Velvet Rump
Temperature
24-28 °C
Target ambient range
Humidity
65-75 %
Substrate / enclosure RH
Adult DLS
13-16 cm
Average - varies per individual
Moult interval
Sling 3-6w - Juv 2-3.2mo
Adult 11-16mo
Adult cycle = mature females; males never moult again after maturity
About
Velvety black rump tarantula from the Chaco of Bolivia, Paraguay and northern Argentina - one of the calmest Acanthoscurria, and the species long traded in the hobby as "A. sternalis" (a synonym). Despite the old "Brazilian Black Velvet" trade name it is not Brazilian. Females reach about 13-15 cm, mature around six years (a published life-cycle study gives roughly 20 moults) and can live well past a decade. A big, docile, always-visible display spider that eats everything offered.
Husbandry cheat sheet
- Origin
- Bolivia / Paraguay / Argentina
- Habitat
- Chaco scrub and grassland
- Temperament
- Docile
- In your collection
- 0
Growth, lifespan & conservation
- Growth rate
- Medium
- Maturity
- ♀ 72mo ♂ 50mo
- Lifespan
- ♀ 18yr ♂ 7yr
- Continent
- South America
- UK availability
- Uncommon
Care Guide
Acanthoscurria musculosa
Black Velvet Rump - a complete husbandry sheet. Use as a starting point and adjust to your individual specimen.
What size enclosure does a Black Velvet Rump Tarantula need?
Adults
35 × 30 cm (14 × 12 in) for a mature adult. Floor space matters more than height.
Slings & Juveniles
House spiderlings in small, appropriately sized deli cups or sling enclosures. Upgrade roughly every 2-3 moults.
To map exact floor space and substrate safety limits for your setup, use our free interactive tarantula enclosure planner.
What temperature and humidity does a Black Velvet Rump Tarantula need?
Heating
The Black Velvet Rumps is comfortable at 24-28 °C. Most UK homes sit below this for much of the year; heat the room rather than the enclosure if winter drops under 21 °C.
Humidity
65-75 %: overflow the water dish once a week and let it dry back. Simple Chaco husbandry - drier is better than wetter.
Ventilation
Cross-ventilation is essential - side-vented enclosures, never stagnant.
What substrate is best for a Black Velvet Rump Tarantula?
Recommended Mixes
Depth
8-10 cm
Notes
Keep substrate dry to barely moist - never soaking. Pack it firm enough to support décor; give 8-10 cm for opportunistic digging.
How do you set up a Black Velvet Rump Tarantula enclosure?
Décor
The Hide
A cork bark half-log, leaning slab, or cork tube placed on the substrate. Many sit in the open once settled.
Water
Always provide a shallow fresh water dish. Keep it full and clean it regularly.
Lighting
No special lighting needed. Ambient room light is enough.
How often should you feed a Black Velvet Rump Tarantula?
Good Feeders
Long refusal worrying you? Separate premoult fasting from genuine problems with our "Is my T okay?" checker.
Is my Black Velvet Rump Tarantula dying or moulting?
Pre-moult signs to look for
Refusing food for weeks is normal before a moult - a healthy Black Velvet Rump Tarantula fasting is almost never an emergency in itself. Watch for slowing down and spending more time in the hide, laying a thick moult mat of web on the floor. New World species like this one often show a bald spot on the abdomen that darkens to near-black as the new skin underneath readies - a darkening bald patch is a reliable countdown, not a disease.
On its back is MOULTING, not dying
A Black Velvet Rump Tarantula lying upside down or on its side with legs curled inwards is almost certainly mid-moult. Do not touch it, do not right it, do not mist it - just remove any live prey (crickets can kill a defenceless moulter) and leave the room.
How long between moults?
For this species, expect a moult roughly every 21-42 days for spiderlings, every 60-95 days for juveniles, and every 190-300 days for sub-adults, with adult females moulting around every 11 months (up to 15.7 months at the extreme). Males never moult again after their ultimate (mature) moult.
After the moult: fang hardening time
The new exoskeleton stays soft, with fangs that cannot grip, for roughly 8 days in this species. Offer no food and no handling for about 8 days - feeding too early is how fresh moulters get injured. The shed exuvium is also the best sexing tool there is - see our tarantula sexing guide for what to look for.
Genuinely worried about behaviour that is not moulting? Our "Is my T okay?" triage tool walks the danger signs one by one.
What ongoing care does a Black Velvet Rump Tarantula need?
🪞 Moulting
Signs: refuses food, abdomen darkens and goes glossy, becomes sluggish, often heavy webbing or a moult mat. During the moult: do not disturb, remove any live prey, keep water available. Wait until the fangs are black and hard (several days for adults, 1-2 for slings) before feeding again. Adult intervals apply to mature FEMALES - a mature male never moults again.
🧹 Cleaning
Daily: check the water dish. Weekly: remove uneaten prey boluses and spot-clean. Full deep clean only every few months.
✋ Handling
One of the most tolerant Acanthoscurria - still handle rarely, at floor level, and wash up afterwards: the flicked hairs itch.
What are the most common mistakes when keeping Black Velvet Rump Tarantulas?
✓ What They Love
- Fresh water dish at all times
- Cross-ventilation
- Stable room temperature
- A proper hide and deep substrate for occasional digging
- Wash hands after maintenance - it can flick hairs
✕ Common Mistakes
- Soaking-wet substrate
- Daily misting
- Heat mat underneath the enclosure
- Assuming the docile reputation means no urticating hairs
Keep exploring: related care guides
More ground-dwelling species and close relatives from our full library:
Acanthoscurria cordubensis
Argentinian Bronze Birdeater
Same genus - full guide →
Acanthoscurria geniculata
Brazilian Giant White Knee
Same genus - full guide →
Acanthoscurria natalensis
Natal Brown Birdeater
Same genus - full guide →
Acanthoscurria chacoana
Bolivian Red Rump
Same genus - full guide →
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