Jupiter Isopods (Cubaris sp.)

There is no mistaking a Jupiter for anything else in the tub. A dark, near-black body is outlined segment by segment in bright yellow, so the whole animal reads like a scaled-down photograph of the planet it is named after. It is one of the most photogenic isopods in the hobby, and, refreshingly for something this striking, one of the more forgiving Cubaris you can keep. Every Jupiter we send is captive-bred here in the UK.

Introduction

This is Cubaris sp. 'Jupiter', also sold as the Jupiter Isopod or simply Cubaris Jupiter, from the limestone karst and tropical forest of Thailand. Like the rest of the genus it takes its cues from a humid, calcium-rich cave environment, but it sits at the accessible end of the Cubaris scale: hardier and less temperamental than the premium cave species, which makes it a sensible first step up for a keeper coming from the wider genus or from hardy Armadillidium. You will also see a higher-contrast 'Jupiter HC' line about, with bolder yellow against deeper black.

Appearance

Adults run around 15 to 20 mm, with a flatter, more conventional isopod profile than the rounded cave species. The signature is the pattern rather than the shape: yellow borders picked out along each segment against a brown-to-black base, brightest on the head and tail. Colour firms up over successive moults, so young stock looks muted next to a settled adult. Like all Cubaris they conglobate, rolling into a tight ball when startled.

Care

Jupiters want warmth and humidity but not stagnant air, so aim for 18 to 26°C and a genuine moisture gradient rather than a single sealed climate. Keep roughly a third of the enclosure damp, with sphagnum, damp leaf litter and soaked rotting wood, and let the rest run drier so the colony can choose. Cross-ventilation, with vents on opposing sides, gives real airflow and heads off the enclosure-wide stagnation that breeds mould. Build the substrate on flake soil, white-rotted hardwood and organic topsoil rather than coco coir, which holds water but feeds nothing to an animal that eats its floor, and scatter limestone through it: this is a karst species, and constant calcium feeds straight into clean moults. Our substrate guide and calcium guide cover the detail.

Diet

Leaf litter and decaying white hardwood do most of the feeding and should be kept topped up. On top of that, offer small amounts of vegetable, a little fruit and the occasional pinch of protein such as fish flake or dried shrimp, and they are keen on mushroom in any form. Carotenoid-rich veg like carrot and pumpkin is worth including, as it may deepen the yellow. Lift anything uneaten within a day or two so leftovers do not turn in the humid corner. A springtail culture alongside handles the microscopic cleanup and belongs in any Cubaris setup.

Breeding

Jupiters breed at a slow but steady pace: not the explosion of a Dairy Cow colony, but reliable once settled, and year-round under stable warmth and humidity. Expect the first mancae within three to six months of a starter group finding its feet, and resist digging after them while they establish. That patient rate is normal for the genus and nothing to worry about. For the fuller picture our complete Cubaris care guide walks through it.

Who is this for?

The Jupiter suits the keeper who wants a bold, camera-ready Cubaris without the cost or the fuss of the rarities, and it makes a strong first cave species before moving up to the demanding morphs like the Rubber Ducky or the reliably-breeding Panda King. It is calm, reasonably visible for a Cubaris, and does useful cleanup work in a bioactive tank on top of earning its place on looks alone.

All stock is captive-bred here in the UK and travels under our live arrival guarantee, packed into a ventilated deli tub with damp sphagnum inside a double-walled box. We post Monday to Thursday by Royal Mail next day before 1pm, with a 20% overcount in every order.