Oniscus asellus 'Orange' Isopods for Sale

Oniscus asellus 'Orange' is a selectively-bred orange morph of one of the most familiar woodlice in the British Isles — properly distinctive coloured stock of the common woodlouse, dressed in a warm orange palette that catches the eye against naturalistic substrate. The wild-type species is the bumpy-backed, slightly-skirted brown woodlouse you'd find under any decaying log or flowerpot across the UK; the Orange morph takes that familiar form and renders it in a properly photogenic warm tone, making it one of the more visually striking native-European isopods available to keepers.

Oniscus asellus itself has a genuinely interesting story. It's one of the largest and most common woodlice native to the British Isles, Western and Northern Europe — described by Carl Linnaeus himself in the founding 1758 edition of Systema Naturae, and considered "the archetypal woodlouse familiar to the general public" in Britain (Wikipedia). The common name "skirted isopod" reflects the species' slightly out-turned lateral segments, which give the body a faintly flared, skirted appearance — a small visual feature that's particularly distinctive in the orange morph.

One charming detail about the scientific name: both halves mean essentially the same thing. "Oniscus" is from Greek for "little donkey", and "asellus" is Latin for the same — making the binomial name a charmingly redundant "little donkey, little donkey." A small but properly memorable bit of natural history.

They sit naturally alongside other native and naturalised UK/Western European isopods in the PostPods range — particularly the various Porcellio scaber morphs and the Armadillidium vulgare 'Big Italy'. Like Porcellio, Oniscus cannot conglobate — they're flat-bodied isopods that scurry rather than roll. Worth knowing if you're choosing between an isopod that rolls into a ball and one that doesn't.

Quick Care Summary

• Scientific Name: Oniscus asellus 'Orange' (note: the listing URL contains a typo — the correct species name is asellus, not "casellus")
• Common Names: Orange Skirted Isopod, Common Woodlouse 'Orange', Oniscus Orange
• Family: Oniscidae
• Origin: Native to British Isles, Western and Northern Europe; selectively-bred orange morph
• Adult Size: Up to approximately 16 mm long × 6 mm wide — one of the larger common woodlice
• Lifespan: 2–3 years typical
• Difficulty: Easy day-to-day; slow to establish initially
• Temperature: 15–25°C — cool-tolerant Northern European species
• Humidity: 60–75% with a moisture gradient — tolerates damper conditions than most isopods
• Ventilation: Good — moist but not wet
• Conglobation: No — flat-bodied; scurries rather than rolls; slightly out-turned "skirted" lateral segments help deter predators
• Behaviour: Active at night and early morning; mostly hidden during day; burrowing
• Breeding: Slow to establish but reliable once settled — not a prolific breeder
• Rarity: Uncommon — selectively-bred coloured stock

What Makes Orange Oniscus Isopods Special

Several factors make the Orange morph a worthwhile addition:

The warm orange palette. This is the headline. A clean orange body — properly photogenic against dark naturalistic substrate, and quite a striking transformation of the familiar brown common woodlouse. Individual variation across a colony adds visual depth, while keeping the overall warm orange effect consistent.

The "skirted" body shape. O. asellus's slightly out-turned lateral segments give the body a subtly flared appearance — particularly noticeable in good light. The common name "skirted isopod" reflects this distinctive shape, and it's amplified visually by the orange colouration.

Lovely etymology. "Oniscus asellus" — Greek "little donkey" + Latin "little donkey" — is a charmingly redundant binomial name. For keepers who appreciate the naturalist side of the hobby, it's the sort of small detail that makes a species memorable.

Native British heritage. Unlike the many Mediterranean and tropical species in the hobby, O. asellus is a native UK species — the woodlouse most British people have actually encountered in their own gardens. There's something genuinely satisfying about keeping a beautifully-coloured morph of an animal that lives wild in your own region.

Linnaeus heritage. Described by Carl Linnaeus himself in the founding 1758 edition of Systema Naturae — proper scientific provenance going back to the foundation of taxonomic naming.

Tolerates damper conditions. O. asellus favours damp habitats and handles higher humidity better than most isopods. Useful for keepers with naturally humid setups (vivariums, paludariums) where drier species would struggle.

Crustacean heritage. Like all isopods, Oniscus is a crustacean — more closely related to marine shrimp and crabs than to insects. Quietly interesting context for what looks at first glance like just a coloured woodlouse.

How Oniscus 'Orange' Compares to Other Isopods

If you're choosing between coloured beginner-tier isopods, here's how the Orange Oniscus fits in:

• vs Porcellio scaber Mix: Both are common woodlice familiar from UK gardens. P. scaber (Rough Woodlouse) is the small, rough-bodied scurrying species; O. asellus (Common Woodlouse) is the slightly larger, smoother-bodied skirted species. Both flat-bodied, both non-conglobating, both native — but distinct visual and behavioural species.
• vs Orange Porcellio scaber morph or similar: Different species. Where a Porcellio orange is the rough-bodied scaber palette shift, the Oniscus Orange is the larger, smoother, skirted-bodied alternative — different scale and texture, similar warm palette.
• vs A. vulgare 'Big Italy': Both are large native/naturalised European Armadillidae/Oniscidae. Big Italy conglobates (rolls into a ball); Oniscus does not. Different behavioural appeal.
• vs Dairy Cow (P. laevis): Both are larger non-conglobating beginner isopods. Dairy Cow shows distinctive black-and-white patterning; Oniscus Orange shows warm orange colouration. Different palettes, both peaceful and easy to keep.

Browse the full Oniscus collection for more O. asellus options, or the broader isopods range for the whole catalogue.

Setting Up the Enclosure

A 6–10 litre plastic container with a secure lid suits a starter colony, with larger setups as the colony grows. Oniscus appreciates damper conditions than most isopods, so emphasise moisture retention while maintaining good ventilation. The 3L Braplast tub works for small starter groups; larger colonies benefit from more space.

Drill ventilation holes on opposite sides for cross-ventilation, covered with fine mesh. Good ventilation is essential — they like it damp, but not stagnant. Provide plenty of hides — cork bark flats, leaf litter, decaying wood, and small bark pieces. They burrow readily, so substrate depth matters. The warm orange colouration shows particularly beautifully against dark substrate and bark. Keep the enclosure dim and out of direct sunlight, since they're predominantly nocturnal. Browse our accessories collection for appropriate enclosures, vents, and other essentials.

Substrate

Build a moisture-retentive substrate suited to this damp-tolerant species:

• Organic topsoil base (pesticide-free) as the foundation
• Sphagnum peat moss generously mixed throughout for moisture retention
• Flake soil mixed in for added nutrition
• Crushed limestone or eggshells distributed throughout for calcium
• Decaying hardwood pieces and rotting white wood incorporated throughout
• Forest moss for humidity and grazing

We recommend a topsoil and sphagnum-based mix rather than coco coir. Substrate depth: 5–8 cm — Oniscus burrow happily and depth supports the nocturnal hiding behaviour.

Top layer: Generous hardwood leaf litter — magnolia leaves, oak, and beech all work well, particularly the soft well-rotted material they prefer to feed on. Add cork bark flats and decaying wood for hides, plus a sphagnum moss patch on the moist side.

Humidity and Temperature

Maintain moderate to moderately-high humidity (around 60–75%) with a clear moisture gradient. Keep one side of the enclosure clearly damp with sphagnum moss and damp leaf litter, while the other side stays moderately humid with good airflow. Oniscus is more tolerant of damp conditions than most isopods — they favour properly moist habitats in the wild — but the gradient still matters, and you should never let the substrate become waterlogged.

As one PostPods customer noted about following the website's care guidance, getting moisture right is the key to keeping isopods successfully — and Oniscus is more forgiving on the damp side than most species, but still needs ventilation to avoid stagnation. "Moist not wet" applies even to this damp-tolerant species.

Temperature should be 15–25°C — they're properly cool-tolerant as a Northern European native species, and UK room temperature works year-round without any heating support. They handle the cooler end of this range comfortably, which makes them well-suited to cooler homes and unheated rooms.

Diet

Oniscus asellus are unfussy detritivores with broad appetites:

• Primary diet (always available): Well-rotted hardwood leaf litter (oak, beech, magnolia), decaying rotting white wood, dried plant matter, lichen, mosses
• Vegetables (1–2x weekly): Yams, sweet potato, carrot, courgette, squash, root vegetables generally. Replace within 24–48 hours.
• Fruit (occasionally): Small amounts of soft fruit
• Protein (1x weekly): Fish flakes, dried shrimp, dried daphnia. Browse our accessories collection for the full range of protein supplements.
• Calcium (essential — always available): Cuttlefish bone, crushed limestone, oyster shell, eggshells. Important for healthy moulting — provide a constant source.

Feeding approach: Maintain a base of leaf litter and decaying wood, supplementing with root vegetables (which they particularly enjoy), occasional fruit, weekly protein, and a constant calcium source. Remove uneaten fresh foods within 24–48 hours to prevent mould in the damper conditions they prefer.

Breeding

Honest reality: Oniscus asellus is not a prolific breeder. Colonies establish slowly and population growth is steady rather than explosive. This is normal for the species across all morphs — patience during the establishment phase is essential, and worth setting expectations on at purchase.

Breeding basics:

• Females carry developing young in a marsupium (fluid-filled brood pouch) and release fully-formed live juveniles
• Multiple broods throughout a female's lifetime, but spaced out
• The warm orange colouration develops as juveniles mature through successive moults
• A pure Orange colony breeds the morph reliably, with some individual variation

For breeding success:

• Stable temperatures within range (18–22°C is ideal)
• A proper moisture gradient with damp-tolerant conditions
• Adequate calcium for breeding females
• Regular protein supplementation
• Plenty of cork bark and leaf-litter hides
• Minimise disturbance during establishment
• A larger starter group establishes faster and provides genetic diversity

The reward for patience is a properly attractive, distinctive colony of a native UK woodlouse in an unusual orange palette — a quiet, steady keep rather than a fast-expanding workhorse colony.

Pair With Springtails

Add a thriving springtail culture to any Oniscus setup. Springtails handle mould and microbial growth at a scale isopods can't manage — particularly important in the damper conditions Oniscus prefers, where mould can establish faster than in drier setups. They coexist peacefully with the Oniscus and form an essential cleanup partnership.

Who Should Buy Orange Oniscus Isopods?

Ideal for:

• Keepers wanting an unusual orange morph of a native UK woodlouse
• Naturalists who appreciate the British/European species heritage
• Bioactive setup builders with naturally damper enclosures (vivariums, paludariums)
• Patient keepers willing to wait for slow colony establishment
• Display enthusiasts wanting visible nocturnal isopods
• Hobbyists building a European native isopods cluster
• Cool-room keepers who don't want a heat-dependent species

Not ideal for:

• Impatient keepers wanting fast, prolific colonies
• Very dry/arid setups (they prefer damper conditions)
• Anyone wanting an isopod that conglobates — Oniscus doesn't roll (try A. vulgare 'Big Italy' or Magic Potion instead)
• Keepers wanting the most rare/exotic-looking species

Realistic Expectations

The orange is the visual story. Set expectations toward the warm orange palette on a familiar woodlouse form. Individual variation exists, but the overall warm tone is consistent.

They don't conglobate. Like Porcellio, Oniscus is flat-bodied and doesn't roll into a ball. They scurry, burrow, and use their slightly out-turned segments to clamp against surfaces.

They're slow to establish. The single most important expectation to set. Initial colony growth is patient and gradual — give them time. Once established they're reliable, but they're never going to be the fastest-expanding colony in the room.

They want it damper than most isopods. The damper-tolerant nature is a real characteristic, not just an option. Drier setups stress them; damp-with-gradient suits them perfectly.

They look like a woodlouse, just orange. Like the Rust Porcellio and Big Italy vulgare, the Oniscus Orange isn't a dramatically exotic-looking species — its appeal is the clean warm colour on a familiar form. The natural-history depth (Linnaeus, native British species, charming binomial etymology) is part of the genuine character.

Building Your Setup

A complete Oniscus Orange setup needs a roomy enclosure, moisture-retentive substrate components, abundant calcium, generous leaf litter and cork bark hides, and protein supplements. Browse our accessories collection for everything you need — enclosures, ventilation, leaf litter, calcium (cuttlebone, limestone, oyster shell), and protein supplements.

Browse the full Oniscus collection for more morphs of this species, or the broader isopods range for the complete catalogue.