Porcellio Nicklesi (True Form) Isopods

Porcellio nicklesi 'True Form' is a striking large Spanish Porcellio displaying the natural wild-type grey colouration — a chunky, impressive isopod best known for its remarkably long uropods (the tail-like projections at the rear) and slightly bumpy, textured body. The "True Form" designation refers to this natural wild-type appearance, distinguishing it from the various selectively-bred morphs (such as Rubivan, Tang, and Dark) that have become popular in the hobby. For keepers who appreciate the original, unaltered form of a species — grey to brown-grey, understated, and authentic — there's genuine appeal in keeping the wild type, and these are properly impressive animals with real presence.

What makes P. nicklesi particularly worth keeping is the combination of that impressive size and distinctive long-uropod form with the rewarding challenge of a giant dry-climate Porcellio. They're rated Medium difficulty and are a genuinely satisfying step up for keepers ready to move beyond the easiest species. They sit among the larger Spanish Porcellio alongside the giant Titan (P. hoffmannseggii), the record-rivalling P. magnificus, and their close relative Bolivari 'Lemonade'.

There's an interesting taxonomic note here: P. nicklesi was originally described by Dollfus back in 1892, and for a time was considered a subspecies of Porcellio bolivari before being recognised as its own distinct species — which is why it shares the cave-dwelling, dry-climate character of its bolivari relative. Like all Porcellio, they cannot conglobate (roll into a ball) — they're surface-dwelling isopods relying on speed and wedging into tight crevices for protection.

They originate from dry mountainous regions and Spanish caves, which gives them specific humidity and ventilation requirements that catch out a lot of keepers. Get those right — and the nuance is genuinely important — and they're a rewarding, impressive species.

Quick Care Summary

• Scientific Name: Porcellio nicklesi (True Form)
• Common Names: Nicklesi, Porcellio nicklesi True Form
• Family: Porcellionidae
• Origin: Spain — dry mountainous regions and caves
• Adult Size: Up to 20 mm body length (30 mm including uropods) — a large Porcellio
• Lifespan: 2–3 years typical
• Difficulty: Medium — specific humidity and ventilation needs; not for beginners
• Temperature: 18–28°C (stable room temperature; not fussy)
• Humidity: Low overall (45–55%) but with localised moisture access — NOT bone dry
• Ventilation: High — excellent cross-ventilation essential
• Conglobation: No — flat-bodied Porcellio, relies on speed and wedging into crevices
• Behaviour: Surface-dwelling, active; males can be territorial
• Breeding: Seasonal; steady rather than prolific; sensitive mancae

What Makes Porcellio nicklesi Special

Several factors make P. nicklesi True Form a coveted large Porcellio:

Impressively long uropods. Their most distinctive feature is the strikingly long uropods (tail-like projections at the rear). Males have noticeably longer uropods than females, which makes sexing adults relatively straightforward once you know what to look for — and gives the species genuine character.

Substantial size and presence. Adults reach around 20 mm in body length, but including those characteristic uropods, total length can reach an impressive 30 mm. They're chunky isopods with real presence, and watching a group of adults moving around an enclosure is genuinely impressive.

The authentic wild-type form. The True Form displays the natural grey to brown-grey colouration of wild specimens. They lack the striking whites, oranges, or high-contrast patterns of the selectively-bred morphs, but there's genuine appeal in keeping the original, unaltered wild type — and the slightly bumpy, textured body has understated character.

A rewarding step up. For keepers who've mastered easier species, P. nicklesi offers the satisfying challenge of a giant dry-climate Porcellio with specific needs. Getting their husbandry right is genuinely rewarding, and success with them is a real milestone in the hobby.

An interesting taxonomic history. Described by Dollfus in 1892 and once considered a subspecies of P. bolivari, their distinct-species status and bolivari kinship add genuine interest for collectors who appreciate the background of what they keep.

How Porcellio nicklesi Compares to Other Giant Porcellio

If you're choosing between large Spanish Porcellio, here's how the Nicklesi fits in:

• vs Bolivari 'Lemonade': Their closest relative — P. nicklesi was once classed as a subspecies of P. bolivari. Both are cave-dwelling dry-climate Spanish Porcellio with similar exacting care. Bolivari 'Lemonade' is the lemon-yellow skeleton morph; Nicklesi True Form is the grey wild type with long uropods. Natural companions for a dry-Spanish collection.
• vs Titan (P. hoffmannseggii): Both are large dry-climate Spanish Porcellio. Titans are bigger and grey-with-white-skirting; Nicklesi are smaller with the distinctive long uropods. Both need dry-with-moisture-access husbandry and strong ventilation.
• vs Porcellio magnificus: Magnificus are record-rivalling vivid orange giants; Nicklesi are the understated grey wild type. Both premium dry-Spanish Porcellio for experienced keepers — different scale and colour.
• vs Porcellio scaber Mix: P. scaber are the hardy, beginner-friendly Porcellio; Nicklesi are the demanding giant. A good progression — master scaber first, then step up to nicklesi.

Browse the full Porcellio collection to compare all species in this genus.

Critical Setup Requirement — Dry, But NOT Bone Dry

This is where things get a bit tricky, and getting it right is genuinely the key to keeping them successfully. There's a common misconception in the hobby that P. nicklesi and other large Spanish Porcellio should be kept bone dry. This isn't quite accurate, and has probably killed more of these isopods than any other mistake.

The reality of "dry" species: Yes, they prefer lower humidity than many other isopods. No, they don't want to be kept completely dry. In their natural Spanish caves and rock crevices, humidity can actually be quite high in the microhabitats where they shelter, even if the surrounding environment is arid. All isopods breathe through modified gills on their undersides, and these need moisture to function — keep them too dry and they'll desiccate. The key is providing excellent ventilation alongside reliable access to moisture.

The correct approach:

• Keep overall humidity low (45–55%)
• Provide a localised moist area — about one-fifth of the enclosure — with damp sphagnum moss over bark and leaf litter
• Keep the remaining ~80% genuinely dry
• Never let the moist area dry out completely, but never let it get waterlogged either
• Excellent cross-ventilation — large mesh vents on opposite sides to move air across the setup
• Add water directly to the moss rather than misting the whole enclosure

As one PostPods customer noted about following the website's care guidance for dry-climate Spanish isopods, proper instructions prevent fatal mistakes. With P. nicklesi, that mistake cuts both ways — too much moisture causes stagnant, mouldy conditions, while keeping them bone dry causes desiccation. The answer is the balance: a mostly-dry setup with one reliable moist retreat and strong airflow.

Setting Up the Enclosure

Large Porcellio need space. A minimum of 6 litres for a starter colony, but larger is better — 12+ litres is preferable for an established colony. Males can be territorial, and crowding causes stress that leads to die-offs. The 3L Braplast tub suits only the smallest starter groups; this species genuinely benefits from more room.

Ventilation is critical. Use large mesh vents rather than drilled holes, positioned on opposite sides to encourage air movement across the setup. Leave a gap of at least an inch between the top of the substrate and the lid to prevent stagnant air pooling. Add cork bark and hardwood pieces for hides and climbing surfaces. Browse our accessories collection for appropriate enclosures, ventilation, and other essentials.

Substrate

A well-draining substrate that won't hold excessive moisture but still provides texture for hiding works best:

• Organic topsoil as a base (pesticide-free)
• Sphagnum peat moss and sphagnum moss for moisture retention in the damp area
• Sand for drainage
• Flake soil for added nutrition
• Rotting hardwood pieces throughout (genuinely important for this species)
• Limestone or calcium sand mixed through for calcium

We recommend a topsoil, sphagnum, and sand-based mix rather than coco coir. Substrate depth: around 5–6 cm. Concentrate moisture in the one damp corner; keep the rest well-draining and dry.

Top layer: Hardwood leaf litter — magnolia leaves, oak, and beech — covering the surface, plus plenty of rotting hardwood and cork bark. Concentrate damp sphagnum moss in the moist corner only.

Temperature

Room temperature works well, anywhere from 18–28°C. They're not fussy about temperature as long as it's stable. Avoid sudden swings and sustained extremes. Most UK homes provide suitable temperatures year-round, with supplementary warmth only needed in particularly cool rooms.

Diet

P. nicklesi are detritivores with a marked preference for decaying hardwood and leaf litter. They're not fussy once established, but getting the diet right supports healthy moulting and reproduction:

• Primary diet (always available): Hardwood leaf litter (oak, beech), decaying white-rotting wood, flake soil. Rotting hardwood is particularly important for large Spanish Porcellio — plenty of decaying wood makes a noticeable difference to colony health and breeding.
• Vegetables (supplementary): Carrot, courgette, sweet potato. Occasional fruit. Replace within 24 hours.
• Protein (1–2x weekly): Fish flakes, freeze-dried shrimp. Place on the dry side, as protein spoils quickly in moist conditions. Browse our accessories collection for the full range of protein supplements.
• Calcium (essential — always available): Cuttlefish bone, limestone pieces, crushed oyster shell. Important for healthy moulting — provide as a constant source.

Feeding approach: Place protein-rich foods on the dry side of the enclosure (they spoil quickly in moist conditions) and remove uneaten fresh food within 24 hours. A modest springtail culture in the moist corner helps manage mould.

Breeding

P. nicklesi are seasonal breeders and won't reproduce year-round like some easier Porcellio species — expect most breeding activity during the warmer months. They're not especially prolific compared to species like P. laevis, and colony growth is steady rather than explosive.

Key breeding points:

• Males have noticeably longer uropods than females, making sexing straightforward
• Mancae (juveniles) are particularly sensitive and need reliable access to moisture without the substrate being wet — many colony crashes happen because the mancae dry out
• Maturity takes around 6–9 months depending on conditions
• Established, well-settled colonies can produce medium-to-large litters

For breeding success: stable temperatures, the correct dry-with-moist-corner setup, excellent ventilation, abundant rotting hardwood and calcium, and patience. Getting a colony to the productive stage requires attention to their specific needs, but it's genuinely rewarding once established.

Common Mistakes to Avoid

• Keeping them too dry: The number one killer. They need moisture access despite being a "low humidity" species.
• Poor ventilation: Stagnant humid air causes mould, mites, and die-offs. Cross-ventilation is essential.
• Too small an enclosure: Large Porcellio need space; cramped conditions stress them.
• Wet substrate: They can't tolerate soggy conditions — the moist area should be damp, not wet.
• No rotting wood: Genuinely important for these species; don't skimp on decaying hardwood.

Pair With Springtails (Carefully)

A modest springtail culture concentrated in the moist corner helps manage mould around fresh foods, without requiring the high humidity springtails typically prefer. In a genuinely dry, well-ventilated enclosure they play a smaller role than in tropical setups, but they still earn their place around the damp retreat.

Who Should Buy Porcellio nicklesi True Form Isopods?

Ideal for:

• Keepers with experience in large Porcellio species
• Those interested in the authentic wild-type form rather than selectively-bred morphs
• Hobbyists who can provide the specific ventilation and humidity balance
• Collectors building a dry-Spanish Porcellio collection
• Anyone wanting an impressive, long-uropod display species

Not ideal for:

• Complete beginners — start with P. scaber or P. laevis (Dairy Cow) first
• Those wanting a set-and-forget species
• Keepers looking for rapid population growth
• Anyone unable to provide excellent ventilation
• Those wanting conglobating ball-rolling species (Porcellio can't roll)

Realistic Expectations

The single most important point: dry, but not bone dry. The biggest mistake with this species cuts both ways — too wet causes mould and die-offs, too dry causes desiccation. They need a mostly-dry setup with one reliable moist retreat and excellent cross-ventilation. Get this balance right and the rest follows.

They're an experienced-keeper species. Rated Medium difficulty, with specific ventilation and humidity needs that catch out a lot of keepers. If you've kept other large Spanish Porcellio you'll likely do fine; if this is your first "giant" Porcellio, expect a learning curve, and consider starting with hardier species first.

They can't roll into a ball. Unlike Armadillidium, nicklesi are surface-dwelling flat-bodied Porcellio relying on speed and wedging into crevices. If you're expecting pillbug ball-rolling, this isn't that kind of isopod.

Breeding is seasonal and steady. Don't expect year-round, explosive growth — they breed mainly in warmer months, and the sensitive mancae need careful moisture management. Patience is rewarded with a settled, productive colony.

It's the understated wild type. The True Form is grey, not flashy — its appeal is authenticity, the impressive long uropods, and substantial size rather than bold colour. If you want vivid colour, the selectively-bred morphs are the alternative, but the wild type has its own genuine charm.

Building Your Setup

A complete P. nicklesi setup needs a roomy, exceptionally well-ventilated enclosure, a well-draining substrate with sand and limestone, abundant calcium, plenty of rotting hardwood and cork bark, and one reliable moist corner. Browse our accessories collection for everything you need — large ventilated enclosures, leaf litter, calcium (cuttlebone, limestone, oyster shell), and protein supplements.

Browse the full Porcellio collection for related giant Spanish species, or read our blog post on the different types of Porcellio isopods for more on this varied and rewarding genus.