Size and growth
Adult Grammostola iheringi reach about 16–18 cm (6.25–7 in) and are moderate growers. Adult Grammostola pulchra reach roughly 15–18 cm (6–7 in) and are slow growers. That affects how quickly Entre Rios Tarantulas and Brazilian Blacks move through sling and juvenile enclosure sizes.
Do not use size alone to estimate age in either Grammostola iheringi or Grammostola pulchra. Sex, feeding and individual variation can change the pace of growth even when two spiders began at a similar size.
Enclosure and lifestyle
Entre Rios Tarantulas are terrestrial, while Brazilian Blacks are terrestrial. Build the Grammostola iheringi enclosure for a terrestrial spider and the Grammostola pulchra enclosure for a terrestrial spider instead of assuming two tarantulas need the same shape of setup.
For Grammostola iheringi, substrate depth, retreat position and usable space should match its terrestrial lifestyle. Apply the same rule separately to Grammostola pulchra; the enclosure should make normal behaviour easy rather than forcing either species into a generic layout.
Temperature, water and moisture
A practical temperature range for Grammostola iheringi is 19–25°C; for Grammostola pulchra, it is 20–24°C. Stable room conditions are more useful for both species than chasing small fluctuations within those ranges.
For Grammostola iheringi, keep a water dish available with a modest moisture gradient; avoid swampy conditions. For Grammostola pulchra, keep a mostly dry setup with surface, water dish, and a modest moisture gradient rather than constantly wet substrate. In both enclosures, keep fresh water available and adjust substrate moisture to how quickly the setup actually dries.
Temperament and maintenance
Grammostola iheringi is a New World species, while Grammostola pulchra is a New World species. That background is useful when planning maintenance, but individual Entre Rios Tarantulas and Brazilian Blacks can still differ noticeably in speed and defensiveness.
With both Grammostola iheringi and Grammostola pulchra, locate the spider before opening the enclosure, use long tools when they make the job safer and keep a catch cup ready for rehousing. Handling is not required for routine care.
Male and female lifespan
Male Grammostola iheringi generally live roughly 4–6 years, while females can live 15–20+ years. Male Grammostola pulchra generally live around 5–8 years, while females can live 20–30 years.
Those lifespan ranges make sex particularly relevant when comparing Grammostola iheringi with Grammostola pulchra. A confirmed female of either species is normally a much longer commitment than a mature male, and the exact age of an older juvenile may be impossible to know.
UK availability and trade notes
In the UK hobby, Grammostola iheringi is currently classed as uncommon, while Grammostola pulchra is classed as common. Stock changes between specialist sellers, captive-produced batches and show weekends, so availability should be checked at the time of purchase.
For records and purchases, use the scientific names Grammostola iheringi and Grammostola pulchra as the main identifiers. Current trade notes list Grammostola iheringi as 'Check current CITES rules before cross-border trade' and Grammostola pulchra as 'Not CITES-listed', so check current requirements before any international movement where controls may apply.
Practical difference in day-to-day care
The practical difference between Grammostola iheringi and Grammostola pulchra comes from the combination of lifestyle, adult size, growth and moisture needs. Those factors change how much substrate, vertical space and maintenance access each enclosure needs.
Whichever species you keep, let the individual spider settle into an enclosure designed for its own biology. That applies equally to Grammostola iheringi and Grammostola pulchra: fresh water, secure housing and patient observation matter more than trying to make the two species behave the same way.