The isopod that pulled the whole hobby into the mainstream. Cubaris sp. “Rubber Ducky” gets its name from the markings on its head, a yellow-and-grey pattern that genuinely does read like a rubber duck’s bill, especially on a well-fed adult.
It is a display animal first. If you want something to eat waste in a vivarium, there are faster and far cheaper options. People keep Rubber Duckies because they look like nothing else in the hobby.
What You’re Buying
A starter colony, not a single animal. Isopods are sold as a group because a colony is the unit that survives: individuals die, colonies establish and produce.
Cubaris are slow. Expect to wait months before you see your first mancae (baby isopods), and longer still before the colony is large enough to split. That patience is the trade you make for the way they look, and it is the single most common source of disappointment for a first-time buyer. Read the isopod care guide before you order, not after.
Keeping Them
Room temperature suits them, roughly 70–80 °F, with stability mattering more than the exact number. Build a moisture gradient rather than one uniform humidity: damp on one side, barely moist on the other, and let them choose.
The non-negotiables:
- Deep substrate: two to three inches on the damp side. Mancae live in the substrate.
- A calcium source: cuttlebone or crushed eggshell. They have a calcium-carbonate exoskeleton and must moult to grow.
- Leaf litter and decaying hardwood, which is most of what they actually eat.
- Cross-ventilation near the top, so the substrate stays damp without going stagnant.
Full detail, including the contested question of whether to feed fish flakes, is in the isopod care guide.
Rubber Ducky vs the other Cubaris
If you’re deciding between our Cubaris, the short version: Rubber Ducky is the recognisable one, Panda King is the high-contrast one, and Frosty Gator is the textured one. All of them are display isopods rather than working cleanup crews. For that job, springtails establish in a fraction of the time.
Frequently Asked Questions
Are Rubber Ducky isopods good for beginners?
They are not a hard animal to keep alive, but they are a frustrating first isopod because they breed so slowly. If this is your first colony, keeping a faster species alongside them teaches you what a thriving culture looks like.
Why are Rubber Ducky isopods expensive?
Slow reproduction. A colony takes months to produce and longer to split, so supply never catches up with demand the way it does for fast-breeding species.
Can I keep Rubber Duckies with other isopods?
You can, but faster species will out-compete them and you will gradually end up with a single-species culture. Keep them on their own.
Will they clean my vivarium?
Not effectively, and it’s a waste of the animal. They’re slow and they hide. Use springtails or a fast isopod for cleanup and keep these on display.
How many do I get?
Ten. The starter colony is a 10-count group of mixed sizes, enough to establish and breed. If the listing is sold out, join the waitlist and you’ll hear first.
