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Asian Forest Scorpion
Heterometrus longimanus
A powerful black forest scorpion distinguished by elongated male pincers, secretive behavior, and a strong preference for humid, sheltered habitats.
LIFESTYLE: Terrestrial
DIFFICULTY: Intermediate
ADULT SIZE: 3.5–5.5 inches (9–14 cm) total length.
GROWTH RATE: Moderate
TEMPERATURE: 24–28°C (75–82°F)
HUMIDITY: 70–85% RH; moist substrate with good ventilation.
About This Species
The Asian Forest Scorpion is a heavily built, dark-colored predator with powerful pincers and a glossy black body. Its appearance is imposing, but its natural behavior is largely shaped by a need for shelter.
And there is an interesting difference between the sexes.
Mature males develop distinctly longer and narrower pincers, while females retain a broader, heavier appearance. Beneath the forest canopy, this scorpion relies on concealed retreats and emerges to hunt nearby invertebrates. Its combination of sexual dimorphism, defensive behavior, and adaptable shelter selection makes it a fascinating species to observe.
Natural History & Behavior
Distribution
Native to parts of Southeast Asia, including Malaysia, Singapore, Indonesia, and the Philippines, with records from India's Andaman Islands. Historical reports from Thailand and parts of mainland Indochina have been revised following taxonomic studies.
Habitat
Inhabits humid tropical forests, including areas with substantial leaf litter, fallen wood, and decaying vegetation. Individuals shelter beneath logs, inside rotten wood, under bark, and in protected spaces around tree bases. These locations provide stable moisture and protection from daytime exposure.
Defensive Behavior
Often retreats when disturbed but may raise its pincers, adopt a defensive posture, or pinch if approached closely.
Its large pedipalps are effective defensive structures. Stinging is also possible, although its venom is generally considered less medically significant than that of dangerous buthid scorpions.
Individual behavior varies, and direct handling is best avoided.
Webbing & Burrowing
In nature, it frequently uses existing shelters beneath wood, bark, and other forest debris. Some field observations also report individuals occupying underground retreats.
In captivity, juveniles may excavate beneath suitable hides, while established adults often remain concealed throughout the day.
Expect greater activity after dark. Although impressive when visible, this is not a consistently exposed display species.
Species Details
Temperament
Defensive
Lifespan
Captive estimates commonly suggest approximately 5–8 years, with females potentially outliving males. Reliable species-specific lifespan averages for each sex remain limited.
Taxonomy
Animalia > Arthropoda > Arachnida > Scorpiones > Scorpionidae > Heterometrinae > Heterometrus > Heterometrus longimanus
Husbandry
Enclosure
Begin with a small, secure enclosure that allows young scorpions to locate food and shelter easily.
As juveniles grow, increase floor space and substrate depth. Adults benefit from a low terrestrial enclosure with approximately 12 inches of length, adequate ventilation, and several protected retreats.
Provide sufficient substrate for digging beneath hides, but secure all heavy decorations against collapse.
Individual housing is the safest general approach.
Substrate
A moisture-retaining mixture of organic soil, coco fiber, and leaf litter provides a suitable forest-floor environment.
Use enough depth to support shelter construction, increasing toward approximately 4–6 inches for established adults where enclosure dimensions allow.
Keep the lower substrate consistently moist without creating stagnant, waterlogged conditions. The upper surface can be slightly drier, giving the scorpion access to different moisture levels.
Feeding
Once young scorpions have left their mother's back, offer suitably sized live prey such as small crickets or roach nymphs.
Increase feeder size gradually as the scorpion develops. Juveniles may feed more frequently during active growth, while established adults generally need less frequent meals.
Use appetite, body condition, and molting behavior to guide feeding. Remove uneaten insects, especially when the scorpion becomes inactive.
Water
Young scorpions benefit from accessible moisture in the substrate and tiny droplets placed along part of the enclosure wall.
Avoid deep dishes for small scorplings.
Introduce a shallow water dish as the animal grows. Established juveniles and adults should have reliable access to clean water.
Maintain moisture within the lower substrate rather than depending entirely on misting. Good ventilation remains essential to prevent stagnant conditions.
Molting
Premolt may involve reduced activity, food refusal, and a noticeably swollen body.
Remove uneaten prey and avoid disturbing the scorpion. Maintaining appropriate substrate moisture helps prevent unnecessary dehydration during recovery.
Newborn scorplings remain on their mother's back during their earliest development. Once they become independent, they can be moved into individual enclosures.
Allow freshly molted juveniles to harden before offering prey. Adults no longer molt.
Breeding & Reproduction
Breeding is achievable in captivity, but identifying compatible, correctly sexed adults is important. Mature males are recognizable by their elongated pincers, although other diagnostic characters may be needed to confirm the species.
Courtship involves the male grasping the female's pedipalps and guiding her toward a suitable surface for spermatophore transfer.
The real commitment comes afterward.
A historical reproductive record, cited in a published 2009 study, reports 34 live young following approximately 12 months of gestation, with birth occurring in July. This is one documented account, not a species-wide average.
Females carry newborn scorplings on their backs. Provide secure, undisturbed conditions until the young become independent.
