Size and growth
Adult Psalmopoeus cambridgei reach about 15–17 cm (6–6.75 in) and are fast growers. Adult Psalmopoeus irminia reach about 13–15 cm (5–6 in) and are fast growers. That affects how quickly Trinidad Chevrons and Venezuelan Suntigers move through sling and juvenile enclosure sizes.
Do not use size alone to estimate age in either Psalmopoeus cambridgei or Psalmopoeus irminia. Sex, feeding and individual variation can change the pace of growth even when two spiders began at a similar size.
Enclosure and lifestyle
Trinidad Chevrons are arboreal, while Venezuelan Suntigers are arboreal. Build the Psalmopoeus cambridgei enclosure for an arboreal spider and the Psalmopoeus irminia enclosure for an arboreal spider instead of assuming two tarantulas need the same shape of setup.
For Psalmopoeus cambridgei, substrate depth, retreat position and usable space should match its arboreal lifestyle. Apply the same rule separately to Psalmopoeus irminia; 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 Psalmopoeus cambridgei is 22–27°C; for Psalmopoeus irminia, it is 22–27°C. Stable room conditions are more useful for both species than chasing small fluctuations within those ranges.
For Psalmopoeus cambridgei, maintain moderate moisture with strong ventilation and constant water. For Psalmopoeus irminia, maintain moderate moisture with strong ventilation and access to water. In both enclosures, keep fresh water available and adjust substrate moisture to how quickly the setup actually dries.
Temperament and maintenance
Psalmopoeus cambridgei is a New World species, while Psalmopoeus irminia is a New World species. That background is useful when planning maintenance, but individual Trinidad Chevrons and Venezuelan Suntigers can still differ noticeably in speed and defensiveness.
With both Psalmopoeus cambridgei and Psalmopoeus irminia, 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 Psalmopoeus cambridgei generally live roughly 3–4 years, while females can live 10–12 years. Male Psalmopoeus irminia generally live roughly 3–4 years, while females can live 10–12 years.
Those lifespan ranges make sex particularly relevant when comparing Psalmopoeus cambridgei with Psalmopoeus irminia. 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, Psalmopoeus cambridgei is currently classed as common, while Psalmopoeus irminia 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 Psalmopoeus cambridgei and Psalmopoeus irminia as the main identifiers. Current trade notes list Psalmopoeus cambridgei as 'Check current CITES rules before cross-border trade' and Psalmopoeus irminia as 'Check current CITES rules before cross-border trade', so check current requirements before any international movement where controls may apply.
Practical difference in day-to-day care
The practical difference between Psalmopoeus cambridgei and Psalmopoeus irminia 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 Psalmopoeus cambridgei and Psalmopoeus irminia: fresh water, secure housing and patient observation matter more than trying to make the two species behave the same way.