White Shark Isopods (Cubaris sp.)

The name oversells the menace. The White Shark is a dwarf Cubaris barely 8 mm long, one of the smallest in the UK hobby, and about as fierce as a grain of rice. What earns the name is the markings: a bright orange front, a pale midsection and a dark blue-black rear, arranged so that a curled animal reads like the silhouette of a shark mid-turn. It is a lot of colour on a very small package, and unusually for a Cubaris it breeds like it means it. Every colony we send is captive-bred here in the UK.

Introduction

This is Cubaris sp. 'White Shark', a true dwarf from the lime-rich tropical habitats of Thailand, also sold as the White Shark Dwarf Isopod. It sits at the forgiving end of the genus: it shrugs off the sort of minor husbandry slips that would set back a premium species, and because it multiplies quickly a colony recovers from a wobble rather than stalling. That combination of tiny size, real colour and reliable breeding makes it one of the smartest first steps into Cubaris.

Appearance

Fully grown at around 8 mm, this is genuinely a look-closely animal, but the tricolour banding stands out clearly against dark substrate and there are simply more of them moving about than you get with a larger, pricier species. Curled up they look like miniature striped marbles. Colour deepens with age and good feeding, so newly arrived juveniles read paler than the settled adults.

Care

White Sharks like it warm, 24 to 28°C, with the upper end favouring breeding, and a humidity gradient around 60 to 80% rather than a uniformly soaked tub. They are enthusiastic burrowers, so give them depth, 7 to 10 cm, built on flake soil, white-rotted hardwood and organic topsoil with crushed limestone worked all the way through. Skip coco coir and peat as the foundation: the first feeds nothing, and it is the limestone that matters here, mirroring the calcium-rich Thai soils and feeding clean moults. Keep one side damp and one drier, damp like a wrung-out cloth and never with standing water at the base, which is the quickest way to lose a dwarf colony. Our substrate guide and calcium guide have the specifics.

Diet

Leaf litter and rotting white wood are the constant base. On top, offer vegetable once or twice a week, a slice of carrot is the classic way to draw the whole colony up where you can count them, plus regular protein, as these little ones are notably protein-hungry for their size. Keep a constant calcium source, and set fresh food on the drier side so it does not spoil in the warmth. A springtail culture keeps mould in check at a scale even a dwarf isopod cannot.

Breeding

This is the White Shark's real selling point. Where many Cubaris breed slowly and unpredictably, an established colony of these grows fast: give a starter group a month to settle, then warmth, depth and constant calcium, and numbers climb steadily from there. Females carry their young in a brood pouch and the mancae rear happily alongside the adults, so be ready to split or upsize as the colony fills out.

Who is this for?

The White Shark suits the keeper with a nano or planted tank where a larger species would overwhelm the space, and anyone after a self-sustaining cleanup crew or dart-frog feeder that keeps its own numbers up. It is a strong first Cubaris and a poor choice only if you want a big animal you can admire from across the room, or you cannot hold steady warmth and humidity. Compare it with the bolder Panda King or the larger Jupiter if you want more size on show.

All stock is captive-bred here in the UK and ships under our live arrival guarantee, in a ventilated deli tub with damp sphagnum inside a double-walled box, with mixed sizes for a balanced colony. We post Monday to Thursday by Royal Mail next day before 1pm, with a 20% overcount included. Setup components are in our accessories range.