Cristarmadillidium Isopods for Sale UK

Cristarmadillidium is a small genus of European isopods that doesn't get nearly enough attention in the hobby - partly because they're rare in captivity, and partly because they look nothing like what most people picture when they think of an isopod.

The only species I currently stock is the Crystal Pineapple (Cristarmadillidium muricatum), and the name really does tell you everything. These tiny Spanish isopods have a distinctly spiky, ridged exoskeleton in pale yellow to washed-out orange that makes them look more like a miniature piece of jewellery than a woodlouse. One seller's figure puts adults at only 6 to 7 mm (the 1885 description gives 10 mm), making them one of the smallest isopods available in the UK hobby, but their rarity and appearance more than compensate for the size.

Captive-bred, posted Monday to Thursday by Royal Mail Tracked 24 or Next Day, with a live arrival guarantee and 20% overcount as standard.

The One Thing to Know Before You Buy

In the wild, Crystal Pineapples live in south-east Spain and on Ibiza, mostly in limestone caves, with some populations in limestone soils away from caves. Kept, they want something different from most of the hobby, which runs on high humidity and damp substrate: good airflow and mostly dry conditions, with a small damp area for hydration.

If you're coming from Cubaris or Armadillidium and you're used to misting regularly, you'll need to adjust your instincts here. They're not difficult once you understand what they want, but they are different. My humidity guide explains how to build the gradient they need.

Frequently Asked Questions

What is a Crystal Pineapple isopod?
Crystal Pineapple is the hobby name for Cristarmadillidium muricatum, a rare Spanish isopod with a spiky, ridged exoskeleton in pale yellow to soft orange. Adults are tiny, 6 to 7 mm by one seller's figure, making them one of the smallest isopods kept in the UK - and one of the most distinctive.

Are Crystal Pineapple isopods hard to keep?
Not hard, but different. Kept, they want good ventilation and mostly dry substrate with just a small damp corner - the opposite of what most isopods need. Keepers who mist them like a Cubaris will lose them. Get the dryness right and they're easy.

Do Crystal Pineapple isopods roll into a ball?
Yes. Cristarmadillidium are conglobators, like Armadillidium - they roll into a ball when disturbed, though their spiky, ridged shell makes the result look rather different from a smooth pill bug.

How big do Crystal Pineapple isopods get?
One seller gives 6 to 7 mm for adults, and the 1885 description 10 mm, which puts them among the smallest isopods in the UK hobby. They're a display and collector species rather than a working cleanup crew.

Why are Crystal Pineapple isopods rare?
The genus is uncommon in captivity, breeds slowly, and comes from a narrow range in south-east Spain and Ibiza, mostly in limestone caves. Combined with their unusual appearance and steady collector demand, that keeps supply tight.

Browse the wider range in isopods for sale. If you have questions about setting up a drier enclosure before you buy, do get in touch and I will help.