How fast does it grow?
Orange Baboon Tarantulas are generally described as fast growers. That gives a useful expectation for Pterinochilus murinus, but it is not a promise that every sling will reach the same size at the same age.
Adult Pterinochilus murinus reach about 13–15 cm (5–6 in). The time taken to get there depends on sex, feeding, temperature and ordinary individual variation.
Moult intervals change with age
Small Orange Baboon Tarantulas often moult more frequently because they are growing rapidly. As Pterinochilus murinus gets larger, the interval between moults normally becomes longer.
Do not treat a longer interval in an older Orange Baboon Tarantula as a problem by itself. Look at appetite, body condition, retreat use and the spider's previous moult pattern.
Feeding and temperature
Feeding influences how quickly Pterinochilus murinus grows, but there is no benefit in keeping the abdomen constantly overfilled. Offer suitable meals and let appetite guide the interval.
A practical temperature range for Pterinochilus murinus is 20–26°C. Stable conditions are preferable to pushing the temperature upward in an attempt to force faster growth.
Male and female growth
Male Pterinochilus murinus usually mature sooner and have a shorter lifespan of about around 3–4 years, while females can live 10–14 years. That difference means two similar-sized juveniles may eventually follow very different timelines.
Sex cannot be judged reliably from growth speed alone. Use a suitable moult when possible instead of assuming a faster-growing Orange Baboon Tarantula must be male.
Tracking growth
Record moult dates for Pterinochilus murinus and note approximate size when rehousing. You do not need precise measurements after every moult; a simple record is enough to show whether the spider is growing steadily.
Photographs taken after an Orange Baboon Tarantula has hardened can also help show changes over time, provided the spider is not disturbed simply to get a measurement.
When growth means rehousing
Rehouse an Orange Baboon Tarantula when its current enclosure no longer gives enough retreat space, substrate or safe access for maintenance. Do not move Pterinochilus murinus after every moult automatically.
Prepare the larger enclosure before the transfer. The goal is to keep each stage of Pterinochilus murinus's growth in housing that is secure and practical, not to race toward the adult enclosure.