Porcellio expansus

🐜 Technical Sheet – Porcellio expansus

Scientific name: Porcellio expansus
Common name: Expansus isopod
Family: Porcellionidae
Origin: Mediterranean region, mainly Spain

🧬 Description

Porcellio expansus is a large and robust terrestrial isopod, considered one of the biggest species within the Porcellio genus. It has a rough-textured, elongated body with grayish or ochre tones. Its most striking feature is the pair of long, prominent uropods at the rear, giving it a prehistoric look.

📏 Size

Adults: Up to 2.8–3.0 cm
Juveniles: 2–4 mm at birth

🌡️ Ideal Conditions

Temperature: 20–26 °C
Humidity: Medium to high (60–80%)
Ventilation: High (essential to prevent mold)
Lighting: Indirect or low light preferred

🏠 Recommended Terrarium

Terrarium type: Horizontal, with deep substrate and good ventilation
Substrate: Coconut fiber, leaf litter, bark, moss, and decaying wood
Decoration: Large bark pieces, flat stones, and natural hiding spots

🍽️ Diet

Detritivores. They feed on:

• Dry leaves
• Decaying wood
• Vegetables (carrot, zucchini, cucumber, etc.)
• Calcium sources (cuttlebone, crushed eggshell)

🐣 Reproduction

Internal sexual reproduction
Females carry the eggs in a ventral pouch (marsupium)
High reproductive rate under optimal conditions

✅ Notes

They do not roll up like members of the Armadillidiidae family
Their appearance makes them a popular choice for terrariums and bioactive setups
They require a balanced mix of humidity and ventilation to avoid fungal issues
Compatible with peaceful invertebrates in bioactive environments