White Side / Penguin Isopods (Cubaris sp.)

In five years of keeping isopods - and more than two decades keeping reptiles and other exotics before that - the White Side has stayed one of the small Cubaris I most enjoy watching. You will see it sold under a few different names - most often White Side or Penguin, sometimes Pinguin or simply Cubaris sp. 'White Side' - and many sellers use them for one animal. The names do the describing for you: paler sides and pale edges to every segment on a darker body, so a group moving through leaf litter really does read like a little committee of penguins. They stay small, they cluster under cover, and once a colony settles they are one of the more rewarding of the accessible Cubaris. Every White Side we send is captive-bred, so you are starting with stock already used to life in a home enclosure rather than wild-collected animals that have to adjust to captivity first.

Introduction

Cubaris is the genus at the centre of the modern isopod hobby, and it covers a huge range - from eye-wateringly expensive Thai and Vietnamese forms down to more attainable morphs like this one. The White Side sits at the accessible end: it has the genuine Cubaris look and behaviour, but it is more forgiving than the premium forms. If you have kept a hardier isopod and want your first proper Cubaris, this is a sensible place to begin. You can see how it fits alongside the rest of the genus in our Cubaris collection, and if you have kept a Rubber Ducky, the care here will feel very similar. Our Penguin isopod care guide goes further into the names, the Panda King question and the care.

Appearance

White Sides are compact and neat. Ours are purple-brown to lilac-grey, dark grey on some, with every segment edged paler and the sides paler still, and that pale border is what earns them the White Side name; sellers often describe darker animals, dark grey to black with white along the edges. Like all Cubaris they conglobate, rolling into a tight ball when disturbed, and they spend a good deal of time tucked under bark and in the substrate, so a settled colony rewards a bit of patience. Against a dark leaf-litter background the pale margins really stand out, which makes them a satisfying display animal despite their size.

Sellers put adults at 10 to 15 mm, most often about 14 mm, and the 10 to 15 mm in our care panel is a French seller's range that takes in the others; the animal has not been described scientifically, and we found no published measurement for it.

Care

The single most important thing with any Cubaris is getting humidity and airflow right at the same time. They want things humid, but stagnant, waterlogged air is the usual killer of a Cubaris colony - so you are aiming for a moist enclosure with gentle cross-ventilation, not a sealed damp box. Mist to keep one end of the substrate damp and let the far end run drier, rather than soaking the lot - a tub that reads the same at both ends gives the colony nothing to choose between. On warmth, their band is 20 to 28°C, and a heated UK home sits just under it from autumn to spring, so they want a little extra warmth through the colder months.

Give them a deep, nutritious substrate to burrow into. A good base is flake soil, white-rotted hardwood and organic topsoil, topped with a generous layer of leaf litter and a few pieces of bark for cover. We do not recommend building the substrate around coco coir - it holds moisture but offers little the isopods can actually feed on, and with Cubaris the substrate is part of the diet. Deep substrate matters for a second reason too: like other Cubaris they appreciate the security of burrowing, and a shallow setup leaves them exposed and unsettled. Everything you need to put a setup together is in our accessories range, and our complete Cubaris care guide walks through enclosure, substrate and ventilation in full.

Diet

White Sides are detritivores, and the bulk of their diet is the leaf litter and white-rotted hardwood they live in. On top of that they take small amounts of fresh vegetables - things like courgette, carrot and squash - and benefit from occasional protein such as a little fish flake or dried shrimp, particularly when breeding. Calcium is not optional for a Cubaris: woodlice build a calcium carbonate cuticle, so keep cuttlebone or crushed limestone available at all times to support moulting and a healthy colony. Clear away any uneaten fresh food within a day or two before it moulds in the humid enclosure. Our guide to what isopods eat covers the full picture if you want to build a proper feeding routine.

Breeding

Like most Cubaris, White Sides are slow to start. A new colony spends its early months simply settling in and building numbers quietly, and it can be tempting to assume nothing is happening. Give them stable conditions - consistent warmth, reliable humidity with good airflow, deep substrate and steady calcium - leave them undisturbed, and once they are established they become a dependable, self-sustaining colony. Patience early on is repaid later. Adding springtails as a clean-up crew helps keep the enclosure healthy in the meantime; you will find those in our springtails collection.

Who is this for?

The White Side is fine for a beginner, even as a first isopod, and suits anyone who wants a genuine Cubaris without the demanding care and cost of the premium forms. If you can hold humidity steady while keeping the air moving, and you do not mind a species that takes its time to establish, this is a great choice - and a striking one on display. It is less suited to anyone after fast, hands-off results.

Every colony is captive-bred and ships under our live arrival guarantee, sent in a double-walled box with sphagnum moss in a ventilated deli tub to travel safely. We dispatch Monday to Thursday to avoid animals sitting in the postal system over a weekend.