The Stout Leg Baboon: A Guide to the Eucratoscelus pachypus
Introduction
If you are looking for a spider that defies the typical "spindly" look of a tarantula, look no further than the Eucratoscelus pachypus, commonly known as the Stout Leg Baboon. Native to the arid regions of Tanzania, this species is one of the most anatomically unique spiders in the hobby. It is instantly recognizable by its massively thickened, velvety hind legs, which it uses like biological shovels to anchor itself and excavate deep burrows. For the tarantula keeper, the "Pachypus" is a captivating example of specialized evolution—a rugged, earth toned Old World specialist that looks built for heavy duty work.
Size, Growth, and Longevity
The Stout Leg Baboon is a medium-sized tarantula, reaching an adult diagonal leg span of approximately 10cm to 12cm. What it lacks in leg span, it more than makes up for in density and character. They have a slow to moderate growth rate, which is typical for spiders adapted to harsher, seasonally dry environments. Because they are a hardy Old World species, females can live for a respectable 12 to 15 years. In the hobby, they are often appreciated as "manageable" spiders that feel substantial and "chunky" without requiring the massive enclosures of the 20cm giants.
Temperament and Suitability
As with most Old World baboon spiders, the E. pachypus is strictly for intermediate to advanced keepers. It lacks urticating hairs and relies on its speed and defensive posture for protection. While they are famously reclusive and prefer to stay in their elaborate burrows, they can be very defensive if forced into the open.
They are known for their "statue-like" stillness, followed by an explosive burst of speed if they feel threatened. Because their venom is likely potent (consistent with other African baboon species), they require a keeper who understands how to manage fast moving, fossorial spiders. In the hobby, they are highly valued by those who enjoy observing the complex engineering of a specialized burrower.
Enclosure Setup
The Eucratoscelus pachypus is a dedicated fossorial (burrowing) species. Its entire life revolves around its tunnel system. To thrive in the captivity, you must provide a deep enclosure with a heavy emphasis on substrate depth—at least 15cm to 20cm. A mix of topsoil, clay, and sand works well to allow them to construct the stable, reinforced tunnels they are famous for.
Environmental care is relatively straightforward: they prefer a dryer setup compared to tropical species. While you should always provide a shallow water dish, the substrate should remain mostly dry, with only occasional light overflowing of the dish to provide a moisture gradient deep in the burrow. They do well at temperatures between 24C and 28C. They are excellent hunters and will eagerly snatch crickets or roaches from the entrance of their silk-lined dens, making feeding time a spectacular display of "trapdoor" style predation.
Conclusion
The Eucratoscelus pachypus (Stout Leg Baboon) is a true marvel of African arachnid diversity. Its uniquely "stout" legs and industrious burrowing habits make it a standout Old World species for any serious collection. While its defensive nature and fossorial lifestyle mean it isn't a "display" animal in the traditional sense, the reward of keeping such a specialized and hardy survivor is immense. For the advanced UK keeper, the Stout Leg Baboon is a fascinating addition that brings a touch of the Tanzanian scrubland home.
