Ornithoctonus sp. Blue Femur
Thai Blue Femur - complete care guide
Thai Blue Femur
Temperature
24-27 °C
Target ambient range
Humidity
60-75 %
Substrate / enclosure RH
Adult DLS
12-15 cm
Average - varies per individual
Moult interval
Sling 3-7w - Juv 1.8-3mo
Adult 9-14mo
Adult cycle = mature females; males never moult again after maturity
About
The Malaysian Blue Femur - a bulky, dark-striped earth tiger with brilliant blue rear legs, sold in the UK for years under the label "Haplopelma robustum". Taxonomy reality check: H. robustum is a nomen dubium from Singapore that matches no trade stock - this animal is an undescribed Ornithoctonus from Malaysia that has not been formally seen in the trade for years until recently. Super-defensive, deep-burrowing, medically significant venom, and a genuinely striking pet hole for advanced keepers.
Husbandry cheat sheet
- Origin
- Malaysia
- Habitat
- Tropical forest - deep burrows
- Temperament
- Defensive
- In your collection
- 0
Growth, lifespan & conservation
- Growth rate
- Fast
- Maturity
- ♀ 36mo ♂ 24mo
- Lifespan
- ♀ 14yr ♂ 3yr
- Continent
- Asia
- UK availability
- Rare in the hobby
Care Guide
Ornithoctonus sp. Blue Femur
Thai Blue Femur - a complete husbandry sheet. Use as a starting point and adjust to your individual specimen.
What size enclosure does a Thai Blue Femur Tarantula need?
Adults
30 × 25 cm footprint with 15 cm of substrate.
Slings & Juveniles
Small tubs with 10 cm of substrate and a starter hole.
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 Thai Blue Femur Tarantula need?
Heating
The Malaysian Blue Femurs is comfortable at 24-27 °C. UK homes need supplementary warmth for much of the year; warm the room, never the tank floor.
Humidity
60-75 %: keep the lower substrate slightly damp with strong cross-flow and a drier surface.
Ventilation
Cross-ventilation with moderate humidity.
What substrate is best for a Thai Blue Femur Tarantula?
Recommended Mixes
Depth
15 cm
Notes
Deep and packed, holding burrows. Moisture gradient - faint damp below, dry above.
How do you set up a Thai Blue Femur Tarantula enclosure?
Décor
The Hide
Its own deep burrow with a heavy silk collar - 15 cm+ of packed substrate does the work.
Water
Shallow dish at surface level - keep full and clean.
Lighting
Ambient room light only.
How often should you feed a Thai Blue Femur Tarantula?
Good Feeders
Long refusal worrying you? Separate premoult fasting from genuine problems with our "Is my T okay?" checker.
Is my Thai Blue Femur Tarantula dying or moulting?
Pre-moult signs to look for
Refusing food for weeks is normal before a moult - a healthy Thai Blue Femur Tarantula fasting is almost never an emergency in itself. Watch for slowing down and spending more time in the hide, sealing the burrow entrance with silk (a sealed door usually means "do not disturb - moulting in progress"), laying a thick moult mat of web on the floor. Old World species do not flick urticating hairs, so there is no bald patch to watch - rely on fasting, lethargy and hide time instead.
On its back is MOULTING, not dying
A Thai Blue Femur 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 24-48 days for spiderlings, every 55-90 days for juveniles, and every 130-210 days for sub-adults, with adult females moulting around every 9.3 months (up to 14 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 Thai Blue Femur Tarantula need?
🪞 Moulting
Moults at the burrow bottom behind a plug. Do not dig. Keep prey out and the water dish full; wait until it reopens and hardens. Adult intervals apply to mature females - males never moult after their ultimate moult.
🧹 Cleaning
Weekly: refresh the water dish and clear surface boluses. Full cleans need a rehouse plan.
✋ Handling
Never - among the more aggressive Asian fossorials. Catch cup and lid discipline.
What are the most common mistakes when keeping Thai Blue Femur Tarantulas?
✓ What They Love
- Deep substrate for the burrow system
- Warm with moderate humidity and airflow
- Long tongs and lid discipline
- Anchor points for web collars
- Respect: aggressive, potent venom
✕ Common Mistakes
- Free handling - aggressive Old World
- Shallow substrate
- Stagnant wet air
- Open-lid maintenance
Keep exploring: related care guides
More deep-burrowing species and close relatives from our full library:
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