Dwarf White Isopod Care (Trichorhina tomentosa)

Dwarf White isopods (Trichorhina tomentosa) are a tiny, hardy, all-female tropical species kept less for their looks than for what they do - an outstanding bioactive clean-up crew and a prolific feeder culture for dart frogs and small reptiles. At just 2-4 mm, blind and white, they live almost entirely within the substrate, so their care comes down to keeping things warm (around 21-29°C), humid and moist, with a nutritious organic substrate and plenty of leaf litter to graze on. Because they reproduce by cloning, a single culture multiplies quickly with almost no effort - which is exactly why they are one of the most useful isopods you can keep.

I have kept isopods for five years, and reptiles and other exotics for more than two decades before that, and dwarf whites are the one culture I would tell almost any bioactive keeper to have quietly bubbling away in the background. They are not a display animal - you will barely see them - but as a workhorse cleaner and a living food source they are hard to beat, and they could hardly be easier to keep. Here is everything you need, from a UK point of view.

What are Dwarf White isopods?

Dwarf whites are a species of tiny terrestrial isopod, Trichorhina tomentosa, native to the tropical regions of Central and South America. They are small - adults reach only around 2-4 mm - and plain white to off-white, with a fine, downy surface texture (the species name tomentosa means "downy"). It is worth clearing up a common mix-up here: dwarf whites are white, not blue. The Powder Blue isopod is a completely different species (Porcellionides pruinosus), and the two are often confused. Dwarf whites are also effectively blind and spend almost all their time burrowing through the substrate or clustered under bark, so they are heard of far more than they are seen.

Their standout trait is how they breed. Dwarf whites are parthenogenetic - the colony is all female, and each animal produces young without needing a male at all. That makes a culture almost impossible to sex or pair wrongly, and means a single pot of them will multiply into a thriving colony on its own.

Care at a glance

• Scientific name: Trichorhina tomentosa
• Common names: Dwarf White Isopod, Tropical White Isopod
• Origin: tropical Central and South America
• Adult size: tiny, around 2-4 mm
• Temperature: 21-29°C; warm, so many UK keepers give a little supplemental heat
• Humidity: high; a consistently moist, well-ventilated setup
• Difficulty: very easy - hardy, forgiving and prolific
• Breeding: parthenogenetic (all female, no males needed); extremely fast

Setting up the enclosure

Dwarf whites need very little space, which is part of their appeal - a small, well-ventilated tub is plenty, and a few mesh-covered holes in the lid keep the air moving while holding humidity in. Because they are so small, escape-proofing matters: fine ventilation mesh rather than large gaps.

The substrate does the heavy lifting. It needs to stay moist and be rich in the decaying organic matter they feed on. Build it around a nutritious base of flake soil, white-rotted hardwood and organic topsoil, with a little sphagnum moss worked through to hold moisture and a generous layer of leaf litter on top. I would steer you away from building the mix around coco coir, which you will see recommended as a base almost everywhere, and away from peat, which is too acidic: coir holds moisture but offers next to no nutrition, and for an animal that feeds on its substrate, flake soil and hardwood do the same moisture job while actually feeding the colony. Our substrate guide has the full recipe. A depth of 5 cm or so is ample for such a small species, and scatter cork bark and bark pieces on top for cover.

Temperature and humidity

As a tropical species, dwarf whites do best warm, between 21 and 29°C. In many UK homes that means a little gentle heat for part of the year - a heat mat under one side of the enclosure on a thermostat works well - and you want to avoid prolonged spells below about 18°C, which slow them right down.

They are moisture-lovers, so keep humidity high and the substrate consistently damp, misting with dechlorinated water as needed. The one thing to watch is balance: damp but not waterlogged, and always with airflow, since a wet, stagnant enclosure invites mould. A hygrometer helps while you get a feel for it. The sphagnum moss in the mix acts as a moisture reservoir, evening things out between mistings.

Feeding Dwarf White isopods

Dwarf whites are detritivores, and the bulk of their diet is simply the decaying wood and leaf litter in their enclosure - they will also happily graze the harmless surface mould that appears on damp organic matter, which is part of what makes them such good cleaners. On top of that, the occasional pinch of fish flake or shrimp pellet for protein, and small scraps of vegetable, keep a growing colony well fed. Remove any uneaten fresh food within a day or two so it does not foul the enclosure. For the full picture, our guide to what isopods eat covers it in depth. A calcium source such as a little cuttlebone is worth adding for healthy moulting, though as a small, lightly-armoured species they are far less calcium-hungry than the big Porcellio and Cubaris.

Breeding: effortless by design

This is where dwarf whites really earn their reputation. Thanks to parthenogenesis, every animal in the colony is a breeding female that clones itself without a mate, so numbers build astonishingly fast given just warmth, moisture and food. There is nothing to do to "set up" breeding beyond keeping conditions stable - a healthy culture will explode in numbers on its own, and you will soon have far more than you started with. That runaway productivity is precisely why they work so well as both a cleaner and a feeder.

What Dwarf Whites are for: cleaners and feeders

Two jobs, and they excel at both. As a bioactive clean-up crew, their tiny size and appetite for waste, mould and decaying matter make them ideal for smaller and planted setups where a larger isopod would be too big or too disruptive - they aerate the substrate and break down organic matter without bothering plants or roots. They pair naturally with springtails, the two together forming a complete micro clean-up crew. And because they are small, soft-bodied and endlessly self-replacing, they make one of the best feeder cultures going for dart frogs and small reptiles and amphibians - a sustainable, live food source you can crop from indefinitely. They cohabit peacefully with frogs, geckos and other small vivarium inhabitants.

Who are Dwarf Whites for, and where to buy them

Dwarf whites suit almost everyone: a complete beginner wanting a bombproof first culture, a bioactive keeper needing a micro clean-up crew, or a frog or gecko keeper after a self-sustaining feeder. The only people they do not suit are those wanting a big, visible display isopod - these are working animals you rarely lay eyes on. If they fit what you need, you will find captive-bred Dwarf White isopods on our listing, shipped with a live arrival guarantee, and if this is your first isopod culture our beginner's guide to keeping isopods covers the wider fundamentals.

Frequently asked questions

Are Dwarf White isopods good for beginners?

Yes - they are one of the easiest isopods you can keep. Give them warmth, moisture and a nutritious organic substrate and they largely look after themselves, breeding readily with almost no intervention.

Do Dwarf White isopods need a male and female to breed?

No. Dwarf whites are parthenogenetic, meaning the colony is all female and each animal produces young without a mate. A single culture will multiply on its own - one of the main reasons they are so popular.

Are Dwarf White isopods blue?

No, they are white to off-white with a downy texture. They are frequently confused with the Powder Blue isopod, which is a different species (Porcellionides pruinosus). If yours are genuinely blue-grey, you likely have Powder Blues rather than dwarf whites.

How big do Dwarf White isopods get?

They are tiny, reaching only around 2-4 mm as adults. That small size is exactly what makes them so useful in small, planted setups and as a feeder for little animals.

Can you use Dwarf White isopods as feeders?

Yes - they are one of the best feeder isopods available. Being small, soft-bodied and extremely prolific, a colony provides a steady, self-renewing live food source for dart frogs and small reptiles and amphibians.

Do Dwarf White isopods need high humidity?

Yes. As a tropical species they want a consistently moist, humid enclosure, though always with good ventilation - damp but not waterlogged - to keep mould in check.