Armadillidium Granulatum White Pearl Isopods

White Pearl Isopods are one of the most genuinely distinctive Armadillidium morphs available in the UK hobby — a selectively-isolated albino-type colour variant of the well-known Spanish Standard Yellow Granulatum (A. granulatum). Where standard granulatum display dark grey-brown bodies with bright yellow spots, the White Pearl morph shows soft pearlescent cream-to-white colouration across the entire body — properly understated elegance rather than bold pattern contrast. The pale colouration gives them an almost ethereal appearance against dark substrate, and the granulated textured carapace (which gives the species its name) becomes more visible without the distracting yellow spotting that characterises the standard morph.

What makes White Pearl particularly worth keeping is the combination: striking pale colouration paired with the bulletproof A. granulatum hardiness that makes the species universally accessible. Despite the premium appearance, they retain the easy-care, prolific breeding, and forgiving husbandry that makes standard granulatum one of the best beginner Armadillidium choices. The White Pearl morph essentially gives you "Spanish granulatum keeping experience with rare-morph aesthetics" — visual distinction without sacrificing accessible care.

This is genuinely an albino-type morph rather than a random colour variant. The pearlescent pale colouration results from reduced melanin expression — a recessive genetic trait isolated from standard A. granulatum populations through dedicated selective breeding work. Pure White Pearl colonies maintained separately from other granulatum morphs will breed true, preserving the distinctive pale colouration generation after generation. Cross-breeding with standard yellow granulatum produces variable offspring that won't reliably maintain the Pearl appearance.

Quick Care Summary

• Scientific Name: Armadillidium granulatum 'White Pearl'
• Common Names: White Pearl Isopod, Pearl Granulatum, A. granulatum Pearl, Granulatum White Pearl
• Family: Armadillidiidae
• Origin: Selectively-bred morph of Spanish A. granulatum (standard species native to Mediterranean Spanish woodland)
• Adult Size: Up to 22–25 mm — medium-to-large for Armadillidium
• Lifespan: 2–3 years typical
• Difficulty: Easy — genuinely beginner-friendly
• Temperature: 18–26°C (UK room temperature works year-round)
• Humidity: 60–75% with proper moisture gradient — Mediterranean care, NOT tropical
• Ventilation: Medium to high — good airflow important
• Conglobation: Yes — rolls into a tight defensive ball (classic pillbug behaviour)
• Body type: Hard calcified exoskeleton with granulated textured surface
• Behaviour: Nocturnal but active during ambient lighting, social, hardy
• Breeding: Sexual reproduction — prolific once established, breeds true when isolated from other morphs

What Makes White Pearl Isopods Special

Several factors have made White Pearl one of the more sought-after Armadillidium morphs in the UK hobby:

The pale pearlescent colouration is genuinely distinctive. Where most Armadillidium display dark bodies with various pattern types, White Pearl offers soft cream-to-white colouration across the entire body — properly understated against the bold patterns of other morphs. The "pearl" name reflects the slight iridescent quality the pale exoskeleton displays under good lighting, particularly visible on freshly-moulted individuals.

The granulated texture becomes more visible. Standard granulatum's textured carapace is partially obscured by the yellow spotting — the pattern catches attention rather than the surface texture. In the White Pearl morph, the absence of bold pattern makes the granulated bumps and ridges across the body more visible. Up close, the textural detail is genuinely interesting in ways the standard morph doesn't showcase as effectively.

Substantial size with proper presence. At 22–25 mm, White Pearl Isopods are medium-to-large Armadillidium — bigger than common Armadillidium like Zebra Isopods and properly observable from across a room. The pale colouration combined with the size makes them genuine display animals rather than detailed-inspection species.

Albino-type genetics with selective breeding heritage. The White Pearl morph results from isolated selective breeding for reduced melanin expression — a recessive genetic trait maintained over generations. This selective breeding heritage means keeping White Pearl connects you to dedicated genetic work rather than random colour variation.

Bulletproof A. granulatum genetics underneath. Despite the premium morph appearance, White Pearl retain the hardiness that makes standard granulatum universally recommended for beginners. They're among the most forgiving Armadillidium species available — tolerating husbandry variations that would stress more sensitive species.

Prolific breeding once established. Allow 2–3 months for new colonies to settle, then expect reliable colony growth with substantial brood sizes (typically 15–30 young per brood, occasionally higher under optimal conditions). Sub-adults often begin breeding before reaching full adult size when well-fed.

Connection to the wider granulatum morph family. White Pearl is one of multiple recognised A. granulatum morphs:

• Standard Yellow Granulatum: Wild-type — dark grey-brown body with bright yellow spots
• Lemon Granulatum: Higher yellow expression on lighter brown background
• Orange Granulatum (Naranjito): Vibrant orange-and-yellow Spanish locality variant
• White Pearl: This morph — pearlescent pale colouration from reduced melanin

Serious collectors sometimes maintain multiple morph lines as separate colonies — the variety adds genuine interest to Armadillidium keeping.

Conglobation. Like all Armadillidium, they roll into tight defensive balls when disturbed — the classic pillbug behaviour adds character to colony observation. The pale colouration creates a particularly distinctive defensive display compared to dark-bodied species.

How White Pearl Compares to Other Armadillidium

If you're choosing between Armadillidium morphs, here's how White Pearl fits in:

• vs Standard Yellow Granulatum (A. granulatum): Same species, different selectively-bred colour morph. Standard granulatum display dark bodies with yellow spots. White Pearl show uniform pale pearlescent colouration. Identical care — choose Standard for bold spotted pattern, White Pearl for understated elegance and rare-morph appeal.
• vs Naranjito (A. granulatum Orange): Another granulatum morph but with vivid orange-and-yellow colouration. White Pearl offers the pale alternative within the same species. Different colour temperatures (warm orange vs cool pearl) for different aesthetic preferences.
• vs Magic Potion (A. vulgare): Magic Potion shows yellow-and-black dalmatian-style speckling on white bodies. White Pearl shows uniform pale colouration without spots. Both are visually distinctive morphs but with very different aesthetics.
• vs Jelly Bean Isopods (A. vulgare 'St. Lucia'): Jelly Beans show natural multi-colour polymorphism (burgundy, orange, yellow, grey, white individuals within one colony). White Pearl shows consistent pale colouration across the colony. Different aesthetic interests — Jelly Beans for variety, White Pearl for cohesive uniform display.
• vs Zebra Isopods (A. maculatum): Zebra Isopods display classic black-and-white striped patterning. White Pearl shows uniform pale colouration. Different visual styles entirely — Zebra for bold high-contrast pattern, White Pearl for understated pale elegance.

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

Setting Up the Enclosure

A 10–15 litre plastic container or small terrarium suits a starter colony of 10–20. Plastic tubs with clip-lock lids hold appropriate humidity while allowing the proper ventilation Mediterranean species need. The 3L Braplast tub works for smaller starter colonies (5–10 individuals), though established colonies benefit from larger housing as populations grow.

For ventilation, drill multiple holes on opposite sides of the container for cross-ventilation. Medium-to-high ventilation suits granulatum — enough airflow to prevent stagnation but not so much that the moist zone dries out completely. Cover holes with fine mesh to prevent escapes.

Keep the enclosure in a normal-lit area away from direct sunlight. Granulatum tolerate ambient lighting well — they're not strictly nocturnal hiders like some Cubaris species, though they do display more activity during evening hours and early mornings.

Browse our accessories collection for appropriate enclosures, vents, and other essentials.

Substrate

Build substrate appropriate for Mediterranean conditions — White Pearl thrive on the same substrate as standard granulatum:

• Organic topsoil base (pesticide-free) as the foundation
• Sphagnum peat moss mixed throughout for moisture retention
• Crushed limestone or eggshells distributed throughout for calcium availability
• Flake soil mixed in for added nutrition and structure
• Decaying hardwood pieces incorporated throughout for food and structural variety

Substrate depth: 5–8 cm is sufficient. White Pearl aren't deep burrowers but appreciate enough depth for moulting and security.

Top layer: Generous hardwood leaf litter — magnolia leaves work particularly well for long-lasting cover. Add multiple cork bark pieces and decaying wood pieces distributed throughout the enclosure. Multiple hiding options support their social behaviour while leaving open spaces for their activity.

Mediterranean Care, Not Tropical

This is the most important husbandry point. A. granulatum is a Mediterranean species from Spanish woodland — NOT a tropical species, NOT semi-aquatic. Despite what some sources suggest, keeping White Pearl in tropical conditions or paludarium-style setups causes serious husbandry problems.

The proper approach is a moisture gradient:

• Moist zone (¼ to ⅓ of enclosure): Sphagnum moss patches and damp leaf litter on one side. Mist regularly to maintain moisture. This is where moulting individuals will retreat to access humidity.
• Drier zone (⅔ to ¾ of enclosure): Drier substrate with leaf litter and bark cover. Allow this side to dry between mistings.

The gradient lets the colony self-regulate. They'll move between zones based on individual needs. Humidity 60–75% is appropriate — not the 75–80% uniformly high humidity that suits tropical species. Get this wrong and you'll see reduced breeding, mould issues, and stressed animals despite the species' otherwise hardy nature.

Temperature

18–26°C is the comfort range. UK room temperature works year-round in most homes without supplementary heating. Their Mediterranean origins mean they tolerate moderate seasonal variation well — actually preferring gentle seasonal fluctuation over constant conditions.

Avoid sustained extremes. Brief temperature variations within the comfort range are tolerated well, but prolonged cold (below 16°C) or heat (above 28°C) causes stress.

Diet

White Pearl have unfussy detritivore appetites typical of Armadillidium granulatum:

• Primary diet (always available): Hardwood leaf litter (oak, magnolia, beech), decaying rotting wood, dried plant matter
• Vegetables (1–2x weekly): Carrot, courgette, sweet potato, butternut squash, cucumber, mushrooms. Replace within 24–48 hours.
• Fruit (occasionally): Apple, banana, melon — small amounts
• Protein (essential — 1–2x weekly): Fish flakes, dried daphnia, silkworm pupae, freeze-dried peas, dried shrimp. 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 — granulatum's substantial size and frequent moulting demand consistent calcium availability.
• Commercial supplements: Repashy Bug Burger works particularly well and is reportedly a granulatum favourite.

Important: feed in moderation. Their hearty appetites can lead to overfeeding mistakes. Provide portions they can consume in 24–48 hours and remove uneaten fresh foods promptly. Excess food creates mould issues and attracts pests in the moist zones.

Breeding

White Pearl breed reliably under proper conditions — they're among the more prolific Armadillidium morphs available, sharing the breeding characteristics of standard granulatum.

Important: White Pearl reproduce sexually. Some online sources incorrectly suggest A. granulatum can reproduce parthenogenetically (without mating). This is not documented as standard behaviour for the species. Sexual reproduction is the norm for granulatum — you'll need both males and females in your colony for breeding. Mixed-size starter colonies typically contain both sexes.

Breeding observations:

• Females carry developing eggs in a marsupium (brood pouch)
• Live mancae emerge as fully-formed miniature versions of adults
• Brood sizes are substantial — typically 15–30 young per brood, occasionally higher under optimal conditions
• Multiple broods possible per year under stable conditions
• Sub-adults often begin breeding before reaching full size when well-fed
• Pale colouration is present from birth (juveniles aren't translucent like some morphs)

For breeding success:

• Stable temperatures within the comfort range (22–24°C optimal)
• Proper Mediterranean moisture gradient (60–75% humidity)
• Adequate calcium availability throughout enclosure
• Regular protein supplementation
• Multiple hides and bark refuges
• Larger starter groups (15+) provide better genetic diversity

Maintaining the White Pearl morph: To keep the pearl colouration breeding true, don't mix White Pearl with other granulatum morphs (Standard Yellow, Lemon, Orange/Naranjito). Interbreeding with the dominant yellow-spotted standard form produces variable offspring that won't reliably maintain the pale appearance. Within a pure White Pearl line, the recessive trait is maintained and the colony will continue producing pearl-coloured offspring generation after generation.

Pair With Springtails

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

Who Should Buy White Pearl Isopods?

Ideal for:

• Collectors interested in rare albino-type morphs
• Keepers wanting understated pale isopods rather than bold-patterned species
• Existing granulatum keepers wanting to expand into morph lines
• Display setup enthusiasts where unique pale colouration matters
• Selective breeders maintaining recessive trait lines
• Mediterranean bioactive setup builders wanting attractive cleanup crew
• Beginners ready for a step beyond common Armadillidium morphs
• Photographers wanting subjects with distinctive pale appearance against dark substrate

Not ideal for:

• High-humidity tropical setups (their Mediterranean needs conflict with uniformly humid conditions)
• Semi-aquatic or paludarium setups (these are terrestrial Mediterranean isopods, NOT semi-aquatic)
• Mixed colonies with standard yellow granulatum (interbreeding destroys the pure pearl line)
• Setups that can't maintain a proper moisture gradient
• Anyone wanting bold-patterned isopods rather than understated pale colouration

Realistic Expectations

Newly arrived White Pearl Isopods may take 2–3 weeks to acclimate before showing comfortable colony behaviour. During this initial period they'll likely remain hidden more than established colonies — this is normal acclimation, not a sign of poor health.

Pearl intensity varies between individuals. Some specimens display particularly bright pearlescent white tones, others show more cream or off-white shades. The natural variation is part of the morph's character — every colony has its own colour mix rather than completely uniform appearance across all individuals. Pearl intensity tends to develop with successive moults, so newly-emerged juveniles may appear slightly different from fully-mature adults.

Expect Mediterranean care commitment. Don't treat them as tropical species — the moisture gradient and ventilation requirements matter. If you've kept tropical Cubaris, the lower-humidity granulatum care will feel counter-intuitive at first. Trust the Mediterranean adaptation rather than fighting it.

Don't expect them in paludarium-style setups. Despite what some online sources suggest, A. granulatum is NOT semi-aquatic. They're terrestrial Mediterranean isopods that need a proper moisture gradient with genuine dry zones — not water features or constantly-saturated substrate.

Customer feedback for this listing is positive — the existing 5-star review confirms "very quick and easy to purchase" with "quick and well packaged" delivery, supporting consistent service quality.

Building Your Setup

A complete White Pearl setup needs basic substrate components, calcium-rich materials, generous leaf litter, 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, Repashy Bug Burger).

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