Melopoeus minax

🔤 Taxonomy

World Spider Catalog currently treats this taxon as Melopoeus minax. GBIF and much of the hobby trade still use Cyriopagopus minax, and older labels may also use Haplopelma minax.

Use the WSC accepted name for new records, but keep the older name on invoices and source notes so the animal remains traceable.

Older names, trade labels, or important status notes:

• Cyriopagopus minax
• Haplopelma minax
• Ornithoctonus minax

English common names used in the hobby:

• Thailand black tarantula
• Thai black tarantula
• Thailand black earth tiger

📌 Description

Melopoeus minax is the Thailand black tarantula: a deep-burrowing Old World species from Myanmar and Thailand that should be planned as a fossorial display animal, not a visible handling pet.

Adults are usually about 13-16 cm legspan. Females can live many years; mature males become restless and short-lived after maturity.

This is an expert-level tarantula. The appeal is the black coloration and earth-tiger behavior, but the keeper has to manage speed, defensiveness, deep substrate, medically significant bite risk, and a spider that may stay hidden for long periods.

Individuals vary, but husbandry should be designed for the fastest and most defensive response rather than for a calm specimen observed once. This Old World species lacks urticating hairs; retreat, threat display, and biting are its relevant defenses. A settled female may remain below ground for weeks, while a mature male is more likely to roam.

Females are robust and potentially long-lived. Mature males become leggier and generally live a much shorter time after their final molt. Determine sex from a suitable molt when possible rather than relying on size, color, or behavior.

☠️ Venom

Treat this species as medically significant. Bites from large Asian theraphosids can cause severe local pain, swelling, cramping, nausea, dizziness, and prolonged discomfort.

Do not handle it. Use long tools, a catch cup, and a closed-room rehousing plan. Seek medical advice for serious, spreading, allergic, respiratory, or persistent symptoms.

Keep the enclosure away from children and free-roaming pets. Before opening it, close the room, cover gaps where practical, prepare a rigid catch cup with a lid, and clear a working area. Forceps are for moving objects at a distance, not pinning the spider or exploring its tunnel. A bite victim should move away safely, wash the punctures, and contact local medical or poison-information services; the spider should not be captured at further risk.

🌍 Distribution

World Spider Catalog lists Melopoeus minax from Myanmar and Thailand. Hobby animals are often sold as Thailand black or Thai black earth tiger.

The current catalog range is narrower than some unsourced trade descriptions. Preserve a credible breeder locality on labels, but treat “Thai black” as a common name rather than proof that a particular animal came from a documented Thai population.

In the enclosure, the important microhabitat is the burrow: deep shape-holding substrate, a humid lower layer, clean water, and breathable air above the soil. A wet surface is not a substitute for a stable retreat.

Deep soil buffers rapid changes in temperature and moisture during Southeast Asian seasonal weather. Captive conditions should reproduce that usable gradient, not copy rain by saturating the whole enclosure. The spider must be able to choose between a slightly moister lower tunnel and a better-ventilated entrance.

🌡 Climate across the native range

Monthly climate normals from reviewed representative locations within the documented native range; the GBIF records identify the genus, not the species:

Weather data by WorldClim v2.1 · Monthly normals queried by Herpeton Academy from raster values; relative humidity is derived from vapor pressure and mean temperature.

Location references use GBIF.org occurrence data where available; original occurrence records retain their source dataset licenses.

⚖️ Legal status

No current CITES listing was found for Melopoeus minax / Cyriopagopus minax in the official CITES sources checked on 2026-06-03. No species-specific listing was found in Annexes A-D of the EU wildlife trade regulations. The species is not relevant to the Bern Convention because it is not native to Europe.

Local rules on ownership, import, sale, transport, exhibition, breeding, and proof of legal origin may still apply. Keep invoices, seller or breeder details, import or transfer paperwork where relevant, and photos or records that connect the animal to a lawful source.

Record every name used on the transaction documents—Melopoeus minax, Cyriopagopus minax, or Haplopelma minax—so later taxonomic changes do not break traceability. Captive-bred stock with clear parentage is preferable to an animal of uncertain wild origin.

🤌 Husbandry

Keep Melopoeus minax alone. Routine communal keeping is not appropriate for a defensive fossorial Old World tarantula.

Spiderlings can start in small tubs with enough depth to make a tunnel and enough ventilation to avoid stale substrate. Adults need a deep terrestrial enclosure where most height is usable soil rather than empty fall space.

Do not dig it out for viewing. Maintenance should be built around water access, prey removal, and a service gap that does not force the spider out of its burrow.

Useful adult priorities:

• deep compactable substrate
• starter burrow or cork entrance
• secure lid and small service opening
• water dish
• moderately moist lower layer with a drier surface

An adult enclosure around 30 × 30 × 40-45 cm is practical when 25-30 cm is compacted substrate. Use positive latches and ventilation holes narrower than the carapace. The water dish and service opening should be on the side opposite the starter burrow so routine work does not block the spider’s retreat.

Press substrate firmly in layers and begin an angled tunnel beneath cork bark along one wall. The spider will usually extend and web it. Once established, leave the structure alone; repeated excavation removes the safest behavior available to both spider and keeper. A sealed entrance often means premolt or burrow maintenance and should not be opened merely to confirm visibility.

Use smaller deep containers for slings, with prey easy to locate and ventilation too small for escape. Rehouse only when growth, watering, or safe access demands it. Put both old and new enclosures inside a larger smooth-sided tub, have catch cups ready, and guide the spider remotely; never transfer it by hand.

A repeatable maintenance routine reduces surprises:

• Confirm the spider’s position or the state of the entrance.
• Open the smallest possible service gap.
• Refill water and remove only reachable debris.
• Close and latch before moving tools or prey tubs.
• Log meals, refusals, molts, watering, and unusual wandering.

💡 Lighting

No UVB or specialist display lamp is required. Normal room light is enough.

Bright overhead heat lamps usually make care worse by drying the surface while the spider retreats deeper.

Provide a gentle 10-12 hour room day-night cycle. A low-output plant light may be used outside a planted enclosure, but measure the resulting temperature at substrate level. Never expose the enclosure to direct sun.

🌡 Heating and temperature

Aim for about 22-27°C by day, with nights around 20-23°C.

If extra heat is needed, warm the room or one side gently under thermostat control. Do not heat from below; the deeper substrate must remain the safe retreat, not the hottest place.

Stable temperatures matter more than maximizing growth. The 22-27°C structured range is appropriate for routine care, with a small night drop acceptable. Prolonged heat near 30°C dries the water dish and upper soil quickly and can trap the spider between an overheated surface and bottom heat.

💧 Humidity and water

Aim for about 70-85% as a ventilated gradient. Keep the lower substrate lightly moist and provide water without flooding the burrow.

Let the top layer dry somewhat between water additions. Stale wet soil, mold, and condensation are signs to adjust ventilation and watering.

Add water down one side or overflow the dish modestly, then allow it to migrate through the lower substrate. A darker moist band visible through the wall is more useful than chasing an exact hygrometer percentage. Keep another part of the surface comparatively dry and ensure cross-ventilation above it.

Persistent condensation, sour-smelling substrate, spreading mold, flies, or water pooling at the bottom mean the setup is too wet or poorly ventilated. A crumbling lower layer, a consistently empty dish, a shriveled abdomen, or repeated drinking suggests insufficient water. Keep a clean dish available even if the spider repeatedly buries it.

🌿 Enclosure and decoration

Use 20-25 cm or more of compactable substrate for adults. A cork entrance or starter tunnel helps the spider build where maintenance is safer.

Avoid heavy rocks, collapsing decor, mesh that catches claws, and tall empty space above the substrate. Prepare the catch cup before opening the enclosure.

A useful substrate combines unfertilized topsoil and coco fiber with a little excavator clay or clean sand for structure. It should form a tunnel when compressed without becoming muddy or airless. Avoid fertilizers, pesticides, aromatic wood chips, sharp gravel, and loose substrate that slumps as soon as the spider digs.

Anchor cork before introduction and keep heavy objects away from excavatable soil. Spot-clean only what is accessible. Do not destroy a sound burrow for cosmetic cleaning; replace all substrate only for flooding, contamination, persistent pests, or structural failure that cannot be corrected locally.

🪳 Feeding

Feed roaches, crickets, locusts where legal, and occasional worms. Adults usually do well on suitable prey every 7-14 days.

Drop prey near the burrow entrance and remove uneaten insects. Do not dig into a sealed burrow during premolt.

Size prey to the spider’s abdomen. Slings may feed every 4-7 days on small roach nymphs, cricket portions, or safe live prey; juveniles often take food every 7-10 days. Adults commonly need only one suitable item every 10-14 days, with longer fasts around molts. Reduce feeding when the abdomen is markedly wider than the carapace.

Do not push prey underground. Offer burrowing feeders in a smooth dish or disable them so they cannot vanish into the tunnel. Remove uneaten prey within roughly 24 hours and immediately when premolt is suspected. After a molt, wait until the fangs are completely black—often a week or longer in a large adult—before offering food. Vertebrate prey and supplement dusts are unnecessary.

🩺 Common problems

Common problems include collapsed tunnels, dry lower substrate, stale wet soil, escape during water changes, failed molts from dehydration, and risky rehousing.

Surface wandering outside maturity often means the burrow, moisture gradient, or enclosure security needs review.

Also watch for mites concentrated around the mouth, persistent mold in the retreat, a tight death curl, uncoordinated movement, leaking hemolymph, or a bad molt. Lying on the back is the normal molting position, so do not turn the spider upright or pull away its exoskeleton.

If the tunnel floods or collapses, create a safe dry surface area and correct the problem from the side farthest from the spider rather than probing blindly. Serious injury, continuing fluid loss, severe dehydration, or an incomplete molt warrants advice from an exotics veterinarian or a highly experienced invertebrate keeper. Avoid household chemicals and improvised medication.

📌 Conclusion

Melopoeus minax suits an experienced keeper who considers a stable webbed burrow a successful display. Have the deep enclosure, secure service routine, water access, and emergency catch equipment ready before purchase. Patience and prevention matter more than seeing or interacting with the spider.

📚 Sources and further reading

• CITES Checklist and Appendices - legal-status references checked 2026-06-03
• EU wildlife trade regulations - legal-status references checked 2026-06-03
• Bern Convention appendices
• GBIF species backbone entry for Cyriopagopus minax
• World Spider Catalog species entry
• WSC 2026 transfer note for Melopoeus minax
• Tom’s Big Spiders: keeping moisture-dependent tarantulas
• Royal Veterinary College: invertebrate veterinary service and tarantula care
• PubMed review: muscle spasms following Old World tarantula bites