Vex Isopods (Troglodillo sp.)

Warm apricot from end to end, with a glossy, faintly translucent shell that catches the light like polished amber. What makes the Vex distinctive up close is the seaming: every tergite is edged with a fine pale line, so the whole animal reads as a set of overlapping plates rather than one smooth dome. The legs and antennae are almost white against it, and the eyes stay small and dark.

The body is broad and low. Where a Rubber Ducky is tall and rounded, the Vex is wide and flattened, built to wedge into a crevice rather than roll into a ball. It is one of the more striking orange isopods I have had through here, and photographs do not quite do the translucency justice.

What Troglodillo actually is

Troglodillo is a genuine genus, erected by Jackson in 1937 and sitting in the family Armadillidae. It is not a recent split from Cubaris, whatever you may read elsewhere. Only three species have ever been formally described, all of them cave animals from China and Thailand.

The Vex is not one of them. It is undescribed, and its placement in Troglodillo is an attribution made by keepers on the basis of what it looks like, not a published decision. I would rather say that plainly than imply a taxonomy that does not exist. If it is ever formally described the name may change, as it has for several species in this corner of the hobby.

It is reported as a Vietnamese animal, first appearing in the hobby around 2024. That locality comes from the European breeders who introduced it and I have not seen it independently confirmed, so treat it as the trade's best account rather than a documented collection record.

Size and what to expect

Adults are reported at up to around 20 mm, which is large for this genus. You will see it sold as the largest isopod in the hobby, and that is not true: several Porcellio comfortably exceed it. It is a big Troglodillo, which is a more useful claim and still an impressive animal in the flesh.

You will also see it described as having reduced pigmentation and small eyes, on the general principle that cave isopods often do. Look at the photographs. This animal is vividly pigmented and its eyes are perfectly evident. That description has been copied from a generic cave-species template and does not match what arrives.

Keeping them

Treat the Vex as a premium cave Troglodillo and it will settle. Aim for a stable 22 to 26°C, away from radiators, direct sun and sharp swings, because a cave animal is adapted to conditions that barely move.

On humidity I am going to be honest with you: the sources disagree. Some European breeders keep this species noticeably drier than most cave Cubaris, in the region of 50 to 60%, and report better results for it. Others recommend the consistently high humidity you would give a Rubber Ducky. I have not kept it long enough to settle that argument.

What resolves it in practice is a gradient rather than a number. Keep one end damp with sphagnum and deep leaf litter, let the far end run distinctly drier, give it good cross-ventilation over the top, and let the colony choose. If they sit permanently at one end, that is your answer, and it is a better answer than anything I could tell you.

Give them depth and structure. Rotten wood, bark and a substrate deep enough to burrow into, with crevices to wedge under. A permanent cuttlebone and protein a couple of times a week. Everything they need is in food and supplements.

They are slow, and you should expect that

This is the single most important thing to know before you buy. The Vex is a slow breeder even by cave-species standards, with several months to a first brood and then a steady, unhurried trickle. Output drops off over winter. Nobody in the trade reports a fast colony.

That is not a fault, but it does decide who this animal is for. If you want numbers, buy Dairy Cows and enjoy them. If you have kept Cubaris or the other Troglodillo through a full year and want something genuinely uncommon, this is a good one. It sits alongside our Sunset and Camouflage, both of them the same genus.

They are nocturnal and secretive, so a display setup wants low, indirect light and the patience to watch at the right time of day. Expect to see less of them than you would a Porcellio.

What you get

Captive-bred stock, posted Monday to Thursday by tracked next-day Royal Mail in an insulated double-walled box with damp sphagnum and a heat pack when it is cold, and covered by a live arrival guarantee. As with every isopod order, you get at least twenty per cent more animals than you paid for.

These sell out everywhere, so if the size you want is unavailable it is worth checking back rather than assuming it has gone for good. If you are weighing this against another cave species and want a straight opinion, ask me before you order.