Spherillo sp. "Hainan Black" Isopods

Most of the Spherillo isopods a keeper meets are soft, speckled, pastel little things, so the Hainan Black comes as a pleasant surprise: it goes the other way entirely. This is the dark one, a small isopod that reads as near-solid black or deep charcoal across the back, with none of the busy spotting its cousins are known for. In a hobby that often chases pattern, there is something quietly smart about an animal that gets its looks from restraint instead.

The full name is Spherillo sp. 'Hainan Black', and you will sometimes see it shortened to 'Haina Black'. The Hainan spelling is the useful one, because it points to where the animal comes from: Hainan, the tropical island province off the south coast of China. Like the rest of the genus it belongs to the family Armadillidae, the armadillo or pill isopods, and like them it tucks and curls when it feels exposed rather than bolting for cover.

It is a small, unhurried species. I would put mature adults in the region of 12 to 15mm, in line with the rest of the genus, though this is a newer arrival and I would rather you treated that as a guide than a guarantee; I will pin the figure down once I have grown mine on. In the enclosure it behaves like a classic Spherillo, mostly active after dark, grazing over the surface and through the top of the substrate and spending the bright hours tucked underneath.

Care follows the pattern I use for the whole Spherillo group, and the theme is balance rather than wet. Aim for a moderate humidity, somewhere around 60 to 75 percent, damp at one end of the enclosure and drier at the other, and give the box real cross-ventilation; these are not swamp animals, and stale, sodden air will undo a colony faster than anything else. Keep it warm, in the low-to-mid twenties Celsius, and never stand the enclosure on a heat mat, which dries and overheats the floor from below.

Build that floor on a hardwood base of decaying leaf litter and crumbling white-rotted wood, with a little sphagnum at the damp end to hold moisture where you want it. The leaf and wood are food as much as flooring and want topping up as the group works through them, and beyond that they take the usual isopod extras in small amounts, soft vegetables and the occasional trace of protein, plus a steady source of calcium, so keep cuttlebone or crushed shell to hand for rehardening the shell after each moult.

If a solid dark isopod is what you are after, the Hainan Black sits comfortably beside our Black Sapphire, and it shares a homeland with the two-tone Sinodillo 'China' if a Chinese pairing appeals; the rest of the range lives on our isopods for sale page.

The Hainan Black you receive is captive-bred rather than wild-collected, which is how these Asian Spherillo reach UK keepers and part of why they settle so calmly. I count every culture generously, adding around a fifth again over the number you order, and send them out in a ventilated tub with damp sphagnum inside an insulated, double-walled box, dispatched Monday to Thursday by Royal Mail next-day delivery, with a heat pack added in cold weather and a live arrival guarantee behind every order. After five years with isopods and a good deal longer with everything else that shares my shelves, I have a soft spot for the understated ones, and a matte-black pill isopod that asks only for warmth, air and a deep bed of leaf and wood is about as understated as the hobby gets.