Asian Forest Scorpions (Heterometrus longimanus)

Heterometrus longimanus — Introduction & Overview

The Asian Forest Scorpion (Heterometrus longimanus) is a glossy, jet-black forest dweller from Southeast Asia that commands attention under normal light and glows an ethereal turquoise under UV. It’s a classic display scorpion—robust, secretive, and nocturnal—rewarding patient observation with powerful feeding strikes and methodical patrols. For Myco-Patrons who value naturalistic setups and low-handling husbandry, this species offers dramatic presence with manageable care.

Why Keep This Species

  • Striking display: mirror-black armor that fluoresces under blacklight.
  • Hardy when kept warm, humid, and provided deep, tight hides.
  • Educational behaviors: burrow maintenance, nocturnal foraging, threat postures.

Keeper Profile

  • Handling: hands-off; use tools (tongs/catch cups) only.
  • Climate: ~76–82 °F (24–28 °C), humidity 70–85% RH.
  • Habitat: deep, slightly compactable substrate; snug cork-bark hides; good ventilation to prevent mold.

Keeper’s Summary

House a single adult in a terrestrial, front-opening enclosure with a secure lid and cross-ventilation. Provide 4–6″ (10–15 cm) of moist coco-fiber/topsoil mix for burrowing, a snug cork hide, and a shallow water dish refreshed often. Maintain warm, humid forest conditions with a thermostat-controlled side heat source; avoid hot rocks. Feed appropriately sized roaches or crickets at dusk (adults ~1× weekly; juveniles 2–3× weekly). Minimize disturbance; admire nocturnal activity under red or UV-safe viewing light.

🐾 Asian Forest Scorpion — Heterometrus longimanus

  • Common Name(s): Asian Forest Scorpion, Asian Black Scorpion
  • Scientific Name: Heterometrus longimanus
  • Native To: Tropical Southeast Asia (Indonesia, Malaysia, Thailand, Singapore)
  • Adult Size: 4–5.5 in (10–14 cm)
  • Life Span: ~5–8 years in captivity (occasionally longer)
  • Difficulty: Intermediate (hands-off, humidity-dependent)



Characteristics & Temperament

What to expect from Heterometrus longimanus in day-to-day care: bold looks, UV fluorescence, and mostly secretive, nocturnal habits.

Appearance

  • Coloration / Pattern: Uniform jet-black to charcoal exoskeleton with a subtle satin sheen; chelae (pincers) broad and heavily granulated.
  • Build / Form: Stocky terrestrial forest scorpion with large pedipalps, moderate tail (metasoma) length, and sturdy legs suited to leaf-litter and burrowing.
  • Light Response: Fluoresces bright blue-green under UV/blacklight; avoid prolonged direct UV exposure.

Temperament

  • Baseline: Shy to defensive; spends daylight hours hidden, emerges after dusk.
  • Response to Disturbance: Backs into cover with raised pedipalps; may posture or deliver a warning pinch before stinging.
  • Feeding Style: Ambush/opportunistic predator; most responsive at night shortly after lights-out.

Social Housing

  • Primarily solitary. Limited group attempts have been made in spacious, complex enclosures with abundant hides and food, but cannibalism and resource guarding are risks. Default: house singly.

Quick Traits

UV Responsive: Yes Most Active: Nocturnal Handability: Do Not Handle

Keeper Notes

  • Stress Signs: Excessive roaming, persistent defensive postures, refusal to feed, remaining outside hides in bright light.
  • Confidence Builders: Deep, lightly compacted substrate; multiple snug hides; low traffic; consistent feeding schedule at dusk.
  • Display Tips: Use low-glare ambient lighting; for night viewing use red light or brief UV glimpses through UV-safe acrylic.

Care Requirements

Core setup and environmental targets to keep Heterometrus longimanus thriving.

Enclosure Setup

Type: Terrestrial forest/burrowing.

Minimum Size: ~18″×18″×12″ (45×45×30 cm) footprint for a single adult; larger is welcome.

Safety: Secure, escape-proof lid/doors; cross-ventilation; thermostat-controlled side heat source with cable management.

Furnishing Guide

  • Size: Comparable to 20 L or 30–40 L terrestrial terrarium.
  • Lid: Fine mesh or locking front to retain humidity while allowing airflow.
  • Hides: Snug cork rounds/slabs and leaf-litter for tight retreats.
  • Enrichment: Bark, branches, and anchor points for climbing and cover.

Substrate

  • Blend: 60% coco-fiber, 30% organic topsoil (no fertilizers), 10% clay/sand for structure.
  • Depth: 4–6″ (10–15 cm); lightly compact lower layers to support burrows.
  • Purpose: Burrowing, humidity buffering, and secure footing.

Habitat

  • Water: Shallow, stable dish; refresh 2–3× weekly; overflow slightly to keep nearby substrate moist.
  • Décor: Cork bark, leaf-litter, smooth rocks, and hardy live plants (pothos, philodendron) if desired.
  • Behavior Fit: Primarily ground-oriented with occasional climbing; appreciates cluttered, dim retreats.

Environment Targets Set & monitor

Temp
Target 76–82 °F (24–28 °C) with a mild night dip to ~70–74 °F. Provide a gentle warm side; avoid hotspots.
Humidity
Aim for 70–85% RH; keep substrate evenly moist (not waterlogged) and ensure airflow to prevent mold.

Lighting

Ambient room light is sufficient; no UVB required. Maintain a ~12L:12D photoperiod. For night viewing, use red light or brief, UV-safe blacklight observation.

Food & Water

  • Juveniles: Small crickets/roaches 2–3× weekly (prey ~⅓ body length).
  • Adults: Appropriately sized dubia/locusts or large crickets 1× weekly; offer 1–2 items and remove uneaten prey by morning.
  • Hydration: Clean water dish always; occasional light misting to maintain microclimate.
  • Best Time to Feed: Dusk to early night.

Cleaning

  • Spot-Clean: Remove uneaten prey, waste, and mold after feedings.
  • Deep Clean: Refresh substrate every 4–6 months; rinse décor in hot water only (no chemicals).
Safety: Use tongs and catch cups for all enclosure work. This species is defensive and not for handling. Venom is typically of mild–moderate medical significance but can be painful; avoid bites/pinches/stings and secure the enclosure.
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