In 1867 a collector called Erber found a small pill woodlouse living under stones on Tinos, in the Cyclades, its back studded with rows of pointed bumps. Cajetan von Vogl named it Armadillo tuberculatus in 1876, and it is still one of the most distinctive isopods you can keep: up to 15 mm of tuberculate armour from the dry, stony islands of the southern Aegean. Keep it drier than almost anything else in your isopod room, with one small damp corner that never dries out, plus good airflow, warmth and a permanent calcium source, and expect a slow start.
The Species and Its Names
Vogl's paper, read in Vienna in July 1875 and printed in 1876, described the species from animals living "under stones" on Tinos. It went straight into Armadillo, the genus Latreille named in 1802, whose type species is the Mediterranean Armadillo officinalis. That makes it a member of the type genus of the Armadillidae, the family that also holds Cubaris; the familiar Armadillidium pill woodlice sit in a separate family, the Armadillidiidae, despite the similar name.
It has been described as new three more times since, under other names. Budde-Lund described A. cinctus from Kasos, Armathia and Karpathos and A. piger from near Sitia on Crete, both in 1896, and Verhoeff described A. asiaeminoris from Turkey in 1941; all three are now treated as synonyms. Helmut Schmalfuss, whose 1996 paper "The terrestrial isopod genus Armadillo in western Asia" is the modern account of the species, noted, citing Sfenthourakis's 1991 analysis, that island populations differ from one another in consistent ways, but probably not enough to count as separate species. A 2009 study of 578 animals from 17 islands by Kamilari and Sfenthourakis describes the species as varying from island to island in colour, in the size of its tubercles and in the shape of its tail piece.
Where It Lives
Schmalfuss gives the range as many islands in the southern Aegean, from Kithira in the west to Karpathos in the east and from Andros in the north to Gavdos in the south, plus Kastellorizo and one locality on the Turkish mainland north of Antalya, at 400 m altitude. GBIF also lists one museum lot from Dalaman, collected in 1989, and about ten iNaturalist photographs from Turkey's south-west coast, most of them from 2026. Schmalfuss notes that it has not been found on the Greek mainland, nor on the Aegean coast of Turkey.
The habitat is the useful part for a keeper. Schmalfuss describes it living in "dry phrygana biotopes", the low, aromatic scrub of the Greek hillsides, and adds that on a number of small uninhabited islets between the Cyclades and Crete, "with certainly a semidesert climate during summer", it and the powdery Porcellionides pruinosus are the only woodlice at all. Kamilari and Sfenthourakis found it mainly "in dry calcareous rocky habitats, where humidity can become an important limiting factor", with the juveniles generally under rocks, and a 2025 paper by Sfenthourakis describes it as more particular about habitat than A. officinalis and generally rarer, though it can be abundant in the south of its range, especially where limestone is extensive. Dry, stony, limy ground with somewhere damp underneath: that is the brief for the tub.
Size and Appearance
Vogl measured his animals: his description gives a female 12 mm long and 5.25 mm wide, and a male of 10 mm. Schmalfuss examined samples of 20 animals from Kastellorizo, 10 from Serifos and 76 from Gavdos, and the biggest in the Kastellorizo sample was 15.0 × 7.2 mm; the specimens figured in a 2004 paper on the woodlice of Crete are 9 mm. So published animals run from 9 to 15 mm, body only, the range our care panel gives.
The tubercles are the whole look. Vogl counted a row of eight large, pointed bumps across the head, two rows of six to eight on each of the next six body segments, a row of six on the third to fifth tail segments, of which only the middle four stand out strongly, and two small cones on the tail piece. Smooth-backed Armadillo officinalis has none of this. Schmalfuss adds that the tubercles are much more pronounced in juveniles than in adults, which fits our own colony: when our round-up of new and unusual isopods suggested they should probably be called Sonic the Hedgehog isopods, it also noted that the young ones are spikier and paler than the adults.
Colour is less fixed. Vogl saw only spirit specimens, which he describes as yellowish white. Schmalfuss describes the species as brownish grey, with some populations, especially on small islands, brownish yellow or brown. Our own line is a cool slate blue-grey, as the photographs show; we found no published description of wild animals that colour.
A Dry Tub With One Damp Retreat
We found no study that measures the humidity this species needs, and every care figure we found is a keeper's or a seller's. On one point they agree: it needs a drier tub than most isopods get. One German supplier advises keeping about two-thirds of it dry, another says it prefers things a little drier than Porcellio or Armadillidium, and an American one describes a moist retreat at one side with a noticeably drier feeding area at the other. Run it the same way, only drier still: the bulk of the floor dry, and one small damp corner that is never allowed to dry out, because the animals still need somewhere to drink and to moult. The 40 to 60 per cent on our care panel is our own keeping figure for the tub as a whole, not a measured one.
Airflow matters as much as dryness: cross-ventilation beats a single airhole, and a tub with several vents, like our 3L Braplast complete setup, lets you open it up. Build the substrate from organic topsoil, flake soil and white-rotted hardwood, with generous sand for drainage, only a little sphagnum and crushed limestone worked through for calcium, and no coco coir, which holds exactly the water this tub needs to lose and feeds nothing. Cover the dry end in dry oak or magnolia leaves, and give the damp corner something flat to hide under: a stone, or flat bark pieces pressed onto damp substrate, which is as close as a tub gets to the underside of a Greek rock.
Care sheets range between 18 and 28°C, and our panel says 22 to 28°C. A UK room will keep them going through winter, but breeding slows in the cold, so give some additional heat from autumn to spring, on a thermostat at one side of the tub. The one real mistake is treating this species like a tropical one: a sealed lid, a uniformly wet substrate and regular misting.
Food and Calcium
Dry leaf litter and rotting hardwood make up most of the diet and should always be there. On top, give small amounts of vegetable now and then and a little protein once or twice a week; the German supplier that advises two-thirds dry says they eat significantly less of both than other species do. Keep a permanent calcium source, limestone or cuttlebone, for the moults of that heavily sculpted shell, and favour dried foods, since fresh food moulds in the damp corner. Clear leftovers quickly.
How Fast It Breeds
Nobody we found calls it quick. The same German supplier compares its development with Armadillo officinalis and classes it as slow, and the American one calls reproduction slow to moderate and says new cultures often need several months before juveniles show. Give a new colony warmth, the dry tub with its damp corner, strong airflow and constant calcium, then leave it alone. In the wild the young are usually found under rocks, so keep the damp corner undisturbed while a colony builds.
Does It Hiss?
Armadillo officinalis is famous for it: rolled up and disturbed, it rubs its legs against the inside of its shell and makes an audible rattle, which our Red Brick officinalis listing describes. Schmalfuss lists the equipment for it, a ledge of scales on the fourth and fifth pairs of legs, as a character of the Mediterranean Armadillo, but we found no study that records the sound from A. tuberculatus itself, and keepers who have discussed it online disagree. Whether it hisses is still open. What it certainly does is roll: Vogl's plate shows it both stretched out and rolled into a ball, and the bumps stay on show when it is closed.
Two Other Tuberculatus
Two other isopods carry nearly the same name. The Ankylosaur, Reductoniscus tuberculatus, is a tropical dwarf described by Leistikow in 1997 from Sabah, in Malaysian Borneo, and the largest of his three specimens was 5 mm, a fraction of the size of an adult Armadillo tuberculatus. Armadillidium tuberculatum, described by Schmalfuss in 2008, is also Greek, but from the north of the country and in a different genus. If a listing gives only the second half of the name, check the first.
Frequently Asked Questions
How big do Armadillo tuberculatus get?
Up to about 15 mm, body only. Vogl's description gives a 12 mm female and a 10 mm male, the biggest animal in Schmalfuss's Kastellorizo sample was 15.0 mm long, and two figured from Crete in 2004 were 9 mm.
Do Armadillo tuberculatus need humidity?
They need a damp corner, not a damp tub. Keep the bulk of the floor dry, with one small area of damp substrate under bark or a stone that never dries out. In the wild they live in dry rocky places where humidity can become a limiting factor.
Where are Armadillo tuberculatus from?
The islands of the southern Aegean, from the Cyclades to Crete, Karpathos and Kastellorizo, with a few records on Turkey's south-west coast. The species was described from Tinos.
Are Armadillo tuberculatus good for beginners?
They suit a keeper with an easier species or two behind them who can resist wetting the tub; our care panel rates them medium. Once the tub is set up, the care itself is simple.
Do Armadillo tuberculatus hiss?
Not that we can confirm. Armadillo officinalis stridulates and the genus has the anatomy for it, but we found no recording of it in this species.
How fast do Armadillo tuberculatus breed?
Slowly. Sellers call it slow or slow to moderate, and one says new cultures often need several months before young show.
Getting Started
A textured, blue-grey roller with 150 years of published record behind it, for a keeper happy to run a dry tub. The figures on our Armadillo tuberculatus isopods listing match this guide, and the rest of our Armadillo range is there to compare.
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