Spiky Pineapple Cristarmadillidium muricatum

Cristarmadillidium muricatum — the Spiky Pineapple — is one of the most visually distinctive dwarf isopods in the hobby. Covered from head to tail in tiny spiny tubercles (the "spikes"), with a washed-out orange to light yellow coloration, they genuinely resemble miniature pineapples. Native to the temperate habitats of Spain, they are a drier-setup species that clusters under cork bark at night and forages actively after dark. A must-have collector's species for anyone who has graduated past the beginner basics and wants something truly different.

Substrate mix: For best results, use Isopod Paradise Organic Substrate specifically formulated to support healthy colonies. If you would rather mix your own, we recommend a blend of 70% organic topsoil, 10% flake soil, 10% milled sphagnum moss, 8% organics(mushroom compost, earthworm castings and leaf litter) and 2% calcium

Hides & decor: Cork bark (flat pieces and rounds), rotting hardwood, dried leaf litter. They congregate in tight clusters under hides — provide multiple overlapping hide pieces to accommodate this behavior and reduce density stress. Cuttlebone for calcium source.

Moisture: Unlike most other isopods, Spiky Pineapples do not need a steep moisture gradient. Keep the enclosure a half dry and other half as a moist retreat (sphagnum moss under a hide) for hydration and molting. Good ventilation is important. Add springtails to the moist zone.

Detritivores that graze on leaf litter, decaying wood, and organic matter. Smaller feeders given their dwarf size — offer appropriately sized food pieces. Protein supplementation weekly supports colony health and reproduction.

Feeding frequency: weekly. Feed small amounts appropriate to colony size. Remove uneaten soft food within 48 hours. Because the enclosure is kept dry, mold from leftover food is a real risk — feed conservatively.

Moderate breeders. Colonies grow steadily once established, but patience is required — this is not a fast-reproducing species. They are pill isopods (conglobators) that roll into a ball when disturbed. Females carry young in a marsupium and give live birth.

Starting colony tips: Start with at least 10–20 individuals. Keeping the group together in a not-too-large enclosure initially helps them find each other and begin reproducing. Because of their dwarf size, a 6 qt tub is ideal to start — too large an enclosure can slow pairing and reproduction.

Mancae care: Juveniles emerge tiny and translucent. Offer fine food particles on the substrate surface and ensure a consistent moist retreat is accessible for young animals during their first molts.