Ornithoctoninae sp. viridis

There is one Ornithoctoninae that doesn't look like the others, and Ornithoctoninae sp. viridis is it. Across a subfamily defined largely by browns and steely blues, this species carries a faint but unmistakable green iridescence over a dark body, framed by characteristically black femora on each leg. In low light it can glow like oxidised copper — the kind of colour you have to wait for, catch at the right angle, and earn by sitting quietly beside the enclosure. The common name Vietnamese Green Earth Tiger isn't marketing; it's simply the most accurate thing you can say about the animal.

Behaviourally, this is a textbook earth tiger from the forests of southern Vietnam: committed fossorial, fast, and built for the dark corridors of its own making. It excavates with purpose, hunts by ambush, and meets any perceived intrusion with a threat posture that leaves little room for misinterpretation. Appetite is strong and growth rate, for an Old World fossorial, is genuinely satisfying to track season by season.

Depth is the single most important parameter in the enclosure — a minimum of 10 cm of substrate, ideally a moisture-retaining blend of coconut fibre and topsoil that the spider can compact and shape into stable tunnel walls. Keep a water dish filled at all times. Humidity runs higher than many Old World species require and is best maintained by misting one side of the enclosure rather than soaking the whole substrate. Temperatures of 24–28°C suit this species well and are achievable without supplemental heating in most homes. Cross-ventilation matters as much as moisture; warm, damp, stagnant air is what causes problems, not the moisture itself.

This is a species for keepers who already know what Ornithoctoninae demands and want the one member of the group that looks unlike the rest. Ornithoctoninae sp. viridis won't perform for you — it will spend most of its life below the surface, and the green sheen is a reward for patience, glimpsed in the brief moments when the animal surfaces and the light catches it just so. Once it's in a collection, it tends to stay; there is currently nothing else in the hobby occupying quite the same visual space.