Ardentiella sp. 'Phoenix' Isopods

Our Yellow Phoenix came out of this animal. Somebody took Phoenix stock, selected hard for the yellow across successive generations, and pushed the red out of the line until a clean yellow cultured form was all that remained. Phoenix is the parent, and it still carries the red that the selected line lost. If you have looked at the Yellow Phoenix and wondered what it came from, this is it.

What registers first is yellow and black. The body is large and broadly blotched, yellow against black across the segments, with red markers running through the pattern instead of sitting over the top of it. That red is where the confusion starts. Our Red Diablo is red-dominant, with bold red skirting round the edge of every segment; Phoenix is yellow-and-black blotching with red as an accent inside it. People mistake one for the other more than any other pair we keep, so it is worth knowing which you are looking at.

The animal is Ardentiella sp. 'Phoenix', still widely sold as Merulanella sp. 'Phoenix' after a recent revision moved the genus out of Merulanella, and both names stay in use across the trade. It is Vietnamese. Adults settle at around 19mm, large by isopod standards. Behaviour is worth understanding before you build the enclosure, because Phoenix does not burrow. It lives at the surface, gathering in small clusters of three to five in the leaf litter and under flat bark, and a settled colony reproduces fast.

Humidity high, airflow high, at the same time

This is the requirement people get wrong. Phoenix wants high humidity and high ventilation together, and every ordinary trick for lifting humidity works by restricting the air, so the two demands fight. The way out is fine mesh in two facing walls, so the air has to cross the enclosure to get out and never stands over the litter. Standing damp air will kill a colony. Hold humidity at 60 to 75 per cent, running it as a gradient with one end kept damp and the other allowed to dry, and stop short of soaking anything. Temperature belongs between 19 and 26°C, and 21 to 24°C is where they are visibly best. Suffering begins above about 26°C, which makes a room that climbs through summer a problem to sort out before a colony arrives.

Below the surface, run a living substrate at least 8cm deep and keep it damp, even though they rarely go down into it, because that layer is what carries the humidity. Leaf litter goes on generously and works as food as much as cover, with cork bark and branching standing above it. Frass is the other thing Phoenix will not tolerate, and it undoes people who have the ventilation exactly right, so keep it clean and seed springtails into the enclosure on day one. There is always cuttlebone or crushed limestone in there for calcium. Rotten white wood, a little soft vegetable and an occasional protein feed cover the rest of the diet.

Climbers rather than rollers

Ardentiella handle glass and smooth plastic as easily as a cockroach does, and the mancae are no different, which puts the whole burden on the lid. Assume nothing about it and check it. Give them height as well, since they use vertical space far more than floor, and a tall box beats a wide shallow one. Startle one and it may conglobate, though that happens a good deal less often than the body shape implies. None of this is beginner keeping. Being captive-bred makes ours more forgiving than wild stock, but Phoenix still asks for attention. Anyone not ready for that should look at Ember Bee first. Batman is the dark one and Pastel the muted one, our Ardentiella care guide sets out the husbandry in full, and the wider Ardentiella range holds the rest.

Nothing goes out after Thursday, so no box of ours idles in the network from Friday to Monday. Dispatch runs Monday to Thursday, next-day, tracked, Royal Mail, before 1pm. The colony sits on damp sphagnum inside a ventilated deli tub, and that goes into a double-walled outer. A handful of extras join the count you ordered, and live arrival is guaranteed.