Armadillidium serratum 'Hedgehog' Isopods for Sale

Armadillidium serratum — the Hedgehog Isopod — is one of the most distinctive and sought-after spiky isopods available in the UK hobby. Its standout feature is its texture: a spiky, serrated, almost armoured appearance that genuinely resembles a tiny hedgehog, and bears a close resemblance to the famous "Crystal Pineapple" isopods — but at over twice the size. The species name "serratum" refers directly to this saw-toothed, serrated texture, and it's exactly what makes them such a prized collector's piece. For keepers who love the spiky pineapple-style look but want something larger, rarer, and more impressive, the Hedgehog delivers properly.

What makes the Hedgehog Isopod particularly worth keeping is the rare combination of a genuinely unusual, eye-catching appearance with easy, beginner-friendly care. Despite being super rare and highly sought-after, A. serratum is actually straightforward to keep and breed — making it accessible to newcomers as well as a real prize for experienced collectors. They're a substantial, textured, characterful Armadillidium that stands out dramatically in any display setup, and they're easy to maintain once their moderate Mediterranean conditions are met.

The species hails from Spain, and as a Spanish Mediterranean isopod it prefers moderate humidity with good airflow — a less moist environment than many tropical isopods need. Getting this balance right is straightforward and the key to keeping them thriving. Like all Armadillidium, they're true pill woodlice, capable of conglobating (rolling into a tight defensive ball) when disturbed — and the spiky texture makes that rolled, armoured ball particularly striking.

Quick Care Summary

• Scientific Name: Armadillidium serratum
• Common Names: Hedgehog Isopod, Serrated Pill Woodlouse, Serratum
• Family: Armadillidiidae
• Origin: Spain — Mediterranean
• Adult Size: Approximately 20 mm+ — a large Armadillidium (over twice the size of Pineapple isopods)
• Lifespan: 2–3 years typical
• Difficulty: Easy — hardy and beginner-friendly
• Temperature: 18–26°C (UK room temperature works year-round)
• Humidity: Medium (50–65%) with a moisture gradient — Mediterranean care, not high tropical humidity
• Ventilation: Medium — good airflow important
• Conglobation: Yes — rolls into a tight defensive ball
• Behaviour: Active, social, peaceful, reasonably visible once settled
• Breeding: Easy — breeds readily in correct conditions

What Makes Hedgehog Isopods Special

Several factors have made A. serratum one of the most coveted spiky Armadillidium in the UK hobby:

The spiky, hedgehog-like texture. This is the species' defining feature — a serrated, spiky, armoured surface that genuinely evokes a tiny hedgehog. It's a properly distinctive look, quite unlike the smooth bodies of most Armadillidium, and the single biggest reason collectors seek them out. The texture is most striking on mature adults and when the isopod rolls into its defensive ball.

The Pineapple resemblance — at twice the size. The Hedgehog closely resembles the famous "Crystal Pineapple" isopods (the spiky A. vulgare morph), but grows to over twice the size. For keepers who love the pineapple-style spiky aesthetic, the Hedgehog offers the same appeal in a much larger, more impressive package.

Genuine rarity with easy care. This is a standout quality. A. serratum is rated super rare and highly sought-after, yet it's genuinely easy to keep and breed. Most rare, distinctive isopods demand precise husbandry — the Hedgehog gives you a prized, unusual species that's actually accessible to less-experienced keepers. That combination is unusual and valuable.

Substantial, observable size. As a large Armadillidium, the Hedgehog is big enough to properly appreciate the spiky texture — these aren't tiny isopods you struggle to see. They're observable, characterful display animals with real presence.

Easy, reliable breeder. They breed readily in correct conditions, building colonies steadily. This makes them satisfying for keepers wanting to see colony growth, and helps the species become more established and available in the hobby over time.

Conglobation. Like all Armadillidium, they roll into a tight defensive ball when disturbed — and with the Hedgehog's spiky texture, the rolled, armoured ball is a particularly striking sight compared to smooth-bodied species.

How Hedgehog Isopods Compare to Other Armadillidium

If you're choosing between distinctive and Mediterranean Armadillidium, here's how the Hedgehog fits in:

• vs Armadillidium beieri: Both are spiny, textured Greek/Spanish Armadillidium with distinctive surfaces. A. beieri is the spiny, glistening "crystallised" isopod; the Hedgehog is the larger, serrated, pineapple-resembling species. Natural companions in a textured-Armadillidium collection — collectors who like one tend to want both.
• vs Yellow Spanish Granulatum (A. granulatum): Both are larger textured Spanish Armadillidium — granulatum has a granulated, bumpy surface and yellow spots; the Hedgehog has the dramatic spiky serration. Both hardy Mediterranean species — different textures and colour.
• vs Zebra Isopods (A. maculatum): Zebras are smooth-bodied with bold black-and-white striping; the Hedgehog is spiky and textured. Both hardy, beginner-friendly Mediterranean Armadillidium — choose based on whether you prefer striking pattern or striking texture.
• vs Frontetriangulum 'Corfu': Both are distinctive, characterful Armadillidium. Frontetriangulum has the unique triangular "mantis" head; the Hedgehog has the spiky hedgehog texture. Different distinctive features from the rich Armadillidium fauna — collectors often want both.

Browse the full Armadillidium collection to compare all species and morphs.

Setting Up the Enclosure

A 10–15 litre plastic container or terrarium suits a starter colony, with room to expand as the colony grows. Plastic tubs with clip-lock lids hold appropriate humidity while allowing the ventilation Mediterranean species need. The 3L Braplast tub works for smaller starter colonies, with larger housing as the population grows.

For ventilation, drill multiple holes on opposite sides of the container for cross-ventilation. Medium ventilation suits A. serratum — enough airflow to prevent stagnation while maintaining the moist zone of a gradient. Cover holes with fine mesh to prevent escapes.

Provide hiding spots with bark, cork, and leaf litter. As a substantial, reasonably active species, the Hedgehog does well in display setups where its distinctive spiky texture can be appreciated. Browse our accessories collection for appropriate enclosures, vents, and other essentials.

Substrate

Build substrate appropriate for Spanish Mediterranean conditions:

• Organic topsoil base (pesticide-free) as the foundation
• Sphagnum peat moss mixed throughout for moderate moisture retention
• Crushed limestone or eggshells distributed throughout for calcium
• Flake soil mixed in for added nutrition
• Decaying hardwood pieces incorporated throughout
• Sand mixed in for drainage and authentic Mediterranean texture (optional)

Substrate depth: 5–8 cm for burrowing — the Hedgehog appreciates enough depth for moulting and security given its larger size.

Top layer: Generous hardwood leaf litter — magnolia leaves and oak leaves work particularly well for long-lasting cover and food. Add multiple cork bark and tree-bark pieces, plus a sphagnum moss patch on one side to create the moist zone of the gradient.

Humidity and Temperature — Mediterranean, Not Tropical

This is the key husbandry point, and it's straightforward. As a Spanish Mediterranean species, A. serratum prefers medium humidity (around 50–65%) with good airflow — a less moist environment than tropical isopods need. Aim for a moisture gradient rather than a uniformly wet enclosure:

• Moist zone (¼ to ⅓ of enclosure): Sphagnum moss and damp leaf litter on one side, misted to maintain moisture. This is where moulting individuals retreat.
• Drier zone (⅔ to ¾ of enclosure): Drier substrate with leaf litter and bark cover, allowed to dry between mistings.

The gradient lets the colony self-regulate. Like other Spanish Armadillidium, the Hedgehog does better with moderate humidity and good ventilation than with constant tropical wetness — overwetting and stagnant humid conditions are more of a risk than slightly dry conditions. As one PostPods customer noted about following the website's care guidance for Mediterranean isopods, proper instructions prevent the common mistake of too much moisture. When in doubt, err drier and ensure good airflow.

Temperature should be 18–26°C — UK room temperature works year-round in most homes. Their Mediterranean origins mean they tolerate moderate seasonal variation well. Avoid sustained extremes in either direction.

Diet

Hedgehog Isopods are unfussy detritivores with broad appetites typical of larger Armadillidium:

• Primary diet (always available): Hardwood leaf litter (oak particularly), decaying rotting wood, dried plant matter
• Vegetables (1–2x weekly): Carrot, courgette, sweet potato, butternut squash, cucumber. Replace within 24–48 hours.
• Fruit (occasionally): Apple, banana — small amounts
• Protein (essential — 1–2x weekly): Fish flakes, dried daphnia, freeze-dried peas, dried shrimp. Supports reproduction and growth. Browse our accessories collection for the full range of protein supplements.
• Calcium (essential — always available): Cuttlefish bone, crushed limestone, oyster shell, eggshells. Multiple sources distributed throughout — essential for healthy moulting and breeding, particularly given their larger size and textured exoskeleton.

Feeding approach: Provide portions they can consume in 24–48 hours and remove uneaten fresh foods promptly. Excess food creates mould in the moist zone and attracts pests. Correct amounts and a clean enclosure keep a colony healthy.

Breeding

Hedgehog Isopods are easy, reliable breeders — one of the species' genuine appeals despite its rarity. They breed readily once their moderate Mediterranean conditions are met.

Breeding observations:

• Females carry developing eggs in a marsupium (brood pouch)
• Live mancae emerge as fully-formed miniature versions of adults
• The distinctive spiky texture develops as juveniles mature
• Colony growth is steady and reliable in correct conditions

For breeding success:

• Stable temperatures within the comfort range (22–24°C optimal)
• Proper Mediterranean moisture gradient (medium humidity)
• Adequate calcium availability throughout
• Regular protein supplementation
• Multiple bark and cork hides
• Larger starter groups provide better genetic diversity and faster establishment

As an easy-breeding species, the Hedgehog rewards patience with reliable colony growth — and every successful colony helps this super-rare species become more established and available in the hobby.

Pair With Springtails

Add a thriving springtail culture to any Hedgehog Isopod setup. Springtails handle mould and microbial growth at a scale isopods can't manage — particularly useful around protein foods and in the moist zone of the moisture gradient. They coexist peacefully with the Hedgehog and form an essential cleanup partnership for Mediterranean Armadillidium setups.

Who Should Buy Hedgehog Isopods?

Ideal for:

• Collectors seeking a rare, genuinely distinctive spiky isopod
• Keepers who love the Pineapple/Crystal aesthetic but want something larger
• Beginners wanting a rare species that's still easy to keep and breed
• Display enthusiasts wanting striking texture and real presence
• Anyone building a textured or distinctive Armadillidium collection
• Bioactive setup builders wanting a Mediterranean-appropriate, characterful cleanup crew
• Keepers wanting reliable, easy breeding

Not ideal for:

• High-humidity tropical setups (their Mediterranean needs conflict with constant wetness)
• Keepers who tend to overwater (they prefer moderate humidity with dry zones)
• Anyone wanting smooth-bodied or brightly-patterned species (the appeal here is texture)

Realistic Expectations

The spiky texture is the star. Set expectations toward texture rather than colour — the Hedgehog's appeal is its dramatic serrated, spiky, hedgehog-like surface rather than bold patterning. It's most striking on mature adults and when the isopod rolls into its armoured defensive ball.

It's rare but genuinely easy. Don't be put off by the "super rare" rating — unlike many rare isopods, A. serratum is straightforward to keep and breed. It's a prize species that's actually accessible, which is precisely part of its appeal.

It prefers moderate humidity, not constant wetness. As a Spanish Mediterranean species, the Hedgehog does better with a moisture gradient and good ventilation than with uniform tropical dampness. If you've kept tropical species, err drier and ensure good airflow.

Texture develops with maturity. The full spiky, serrated appearance develops as individuals mature, so juveniles may appear less dramatically textured before reaching the impressive adult form.

Expect reliable, steady breeding. As an easy breeder, established colonies build steadily — genuinely satisfying, and a contribution to making this super-rare species more available in the hobby over time.

Building Your Setup

A complete Hedgehog Isopod setup needs basic substrate components, abundant calcium-rich materials, generous leaf litter and bark, and protein supplements. Browse our accessories collection for everything you need — enclosures, ventilation, leaf litter, calcium (cuttlebone, limestone, oyster shell), and protein supplements (daphnia, fish flakes, freeze-dried peas).

Browse the full Armadillidium collection for related Mediterranean and distinctive species, or read our blog post on isopod genetics, colours, and morphs for more on Armadillidium variation.