Breeding Notes
Pterinochilus sp. “Arusha”
Arusha Baboon
Also known as: Arusha Golden Baboon, Arusha Tarantula
Species-specific breeding guidance, seasonal context and practical caveats for experienced keepers.
Species breeding reference
Breeding Notes
Breeding Pterinochilus sp. “Arusha” is very much an advanced keeper’s challenge. If you fancy giving this rare East African beauty a go, mimic the start of the wet season, be patient, and treat all pairings with caution. Sac numbers can be decent but there’s a good dose of unpredictability, so approach with respect—and don’t count your spiderlings before they hatch!
Breeding information for this species is a bit thin on the ground, so this guidance is based on the best available reports, native climate clues, and sensible keeper caution.
Wild Breeding Season
Exact timing isn’t formally documented for Pterinochilus sp. “Arusha”, but given their East African origin, breeding likely coincides with the onset or middle of the regional wet season, when humidity rises and food becomes plentiful.
Wild Environmental Triggers
Shifts in seasonal rain patterns, accompanied by higher humidity and slightly cooler evening temperatures, seem to act as natural triggers. Increased prey availability after the rains likely plays a part, as does the deeper moisture in their burrowing substrates.
Native Climate Context
Think classic East Africa: alternating rainy and dry spells, with bursts of humidity during the wet season and some temperature variation, particularly at night. The Arusha region is famous for its savannahs and woodlands, so this species is used to a mix of warmth, airflow, and the occasional downpour.
Captive Breeding Window
Aim to pair them just after raising enclosure humidity and introducing a subtle drop in night-time temps—a gentle nod to the rainy season. For UK keepers, late spring or early summer conditioning, mimicking those changes, has worked for close relatives.
Pre-pairing Conditioning
Consider offering slightly increased feeds over a month then lightly mist the enclosure, ensuring the substrate is just on the moist side but never soggy. Steady warmth in the day (22–26°C), with a mild night-time decrease, helps ready both spiders. Give the female a couple of weeks with these conditions before trying introductions.
Male Introduction Guidance
Introduce the male in the evening after both have been well-fed and humidity is up. Be prepared for swift, defensive behaviour—this genus doesn’t mess about. Leave plenty of webbing or cover for retreat and always be ready to intervene if things get tense. Monitor closely and don’t leave them together unsupervised for long stretches.
Female Readiness Signs
A well-webbed enclosure and the female lingering around the burrow entrance are promising indicators. If the female is out and about more often after feeding and humidity increases, she might be receptive—but keep in mind, Pterinochilus girls can switch from interested to irritated very quickly.
Post-pairing Conditions
Maintain high humidity for several weeks post-pairing, with stable, warm temperatures and the enclosure kept peaceful. Allow her to retreat undisturbed and avoid any unnecessary rehoming, cleaning or loud disturbances. Offer food but remove uneaten items quickly.
Sac Timeline
Precise timelines aren’t pinned down for this species, but based on close relatives in the genus, expect an eggsac—if successful—around 4 to 8 weeks post-mating. Incubation to first instar might take another 4 to 6 weeks, but this can vary widely.
Incubation Notes
Let the female keep the sac if she’s properly secluded, or be prepared to pull and incubate it artificially at a steady 24–26°C and moderate humidity. There’s a risk of sac abandonment if the female is stressed—gentle, minimal interference is best.
Expected Sling Count
Reliable numbers haven’t been published, but going by similar Pterinochilus species, you might see anywhere from 50 to over 100 slings in a good sac. As always, quality of care and female health make a big difference.
Risks and Cautions
Pairings can be risky—females are large, moody and not shy about dispatching males who linger too long. Egg sacs are easily lost to stress or low humidity. Females may destroy sacs at the slightest environmental disturbance. Breeding these is mostly for seasoned keepers who know what to look for and how to act quickly if things unravel.
Evidence confidence: Low
