Cubaris sp. 'Helios Rubber Ducky' Isopods

The 'Helios Rubber Ducky' is the Rubber Ducky you already know, turned up brighter. It is the same Cubaris sp. with the famous duck-face head, only carrying a more luminous, sun-kissed gold across the body, which is why it takes its name from Helios, the Greek god of the sun. If you already keep the standard Rubber Ducky, think of Helios as the same animal with the colour dialled up rather than a different species.

This is captive-bred livestock, not a cleanup crew. Helios comes from the same Thai karst forests and limestone caves as the rest of the Rubber Ducky line, and it wants the same demanding, high-end care. The dark eye spots set against a paler face, the rounded body, the tight roll into a ball when disturbed: all of it is preserved, just in a warmer, more golden tone. Adults reach roughly 12 to 15 mm and live two to three years.

Warmth matters. I keep mine at around 22 to 26°C, a little above a typical UK room for much of the year, so a low-wattage heat mat on a thermostat set to one side helps through the colder months. Humidity should sit high, but never stagnant. What Helios wants is a gradient rather than a wet box: one damp end kept like a wrung-out sponge under sphagnum moss, and a drier far end under leaf litter, with steady cross-ventilation carrying air between the two. Moist, not wet, is the phrase to hold onto.

Give them depth to burrow into, at least 8 to 10 cm, because much of the colony lives below the surface in its own tunnels. I build a living base from flake soil, rotted hardwood and organic topsoil rather than a plain coco-coir base, which holds moisture and feeds them at the same time. Keep calcium available throughout, whether crushed limestone, cuttlefish bone or oyster shell, since these are karst animals and they lean on it hard, especially breeding females. A starter culture of springtails worked into the substrate keeps mould in check while the colony settles.

Feeding is straightforward once the base is right. White rotten hardwood does most of the dietary work and should always be present, backed by a covering of leaf litter such as oak, beech and magnolia. On top of that, Cubaris take more protein than most isopods, so a little fish flake, dried shrimp or dried daphnia once or twice a week is worth offering on the drier side where it spoils more slowly. Fresh vegetables now and then are fine, but go lightly, as excess food sours quickly in a warm, humid tub.

I will be honest about the pace. Helios is a slow, steady breeder, slower than most premium Cubaris and far slower than the common Porcellio, so this is not the isopod to cut your teeth on. Give a new colony six months or more of stable warmth, humidity and calcium before you expect much, and disturb it as little as you can. Females carry their young in a brood pouch and release tiny, fully formed copies that already show the golden colour, deepening with each moult. If you want more of the Thai line alongside it, the Lemon Blue and Black Diamond sit in the same bracket.

Every order is captive-bred here, boxed double-walled around a ventilated tub of damp sphagnum, and posted Monday to Thursday by tracked next-day Royal Mail with a live-arrival guarantee and a small overcount as standard.