We came home from a reptile expo on September 26 with ten giant canyons. They are Porcellio dilatatus, and they are big. Big enough to get their own 15-quart tub on day one.
Care legend: giant canyon isopod
Get it if you want a big, tough isopod that digs and forgives a dry week. Skip it if you want to watch them all day. They work the night shift.
How we rate: difficulty and visibility come from keepers and from our tub so far. Breeding speed ranks our species against each other, from what we see in our tubs. Size is what keepers and field guides report. Dated counts are still coming.
What they are
Giant canyon isopods are Porcellio dilatatus, a big woodlouse from western Europe. In the wild they live under stones, bark and rotting wood. Field guides list adults to about 15 millimeters, and keepers report 18 to 20 in culture. They do not roll into a ball. They dig, and they hide.
Our tub
Our ten went into their own 15-quart tub, because of their size. It holds deep substrate, leaf litter, a piece of bark and a few springtails to clean up. One end stays damp and the other stays dry, so the colony can pick.
The tub is about three weeks old. We have not counted babies yet, so this guide says what keepers report and marks what we have not seen.
Humidity and the dry end
Giant canyons handle dry better than most isopods. Keepers still say they need a damp corner, especially to molt. Give them a gradient: wet a third of the substrate and leave the rest alone. Then watch where they sit. Animals packed in the damp corner mean the tub is too dry. Animals scattered across the dry end mean you are fine.
Food and protein
Leaf litter is the staple. Oak is a good start. Add protein twice a week, like a pinch of dried shrimp, and leave a piece of cuttlebone in the tub for calcium. They are not picky. Pull out whatever they leave after a day or two, or it molds.
How fast they breed
Middle of the pack. In our tubs giant canyons sit ahead of our zebras and Montenegros and behind the dairy cows and powder oranges. Keepers mostly agree they breed readily with steady food and room to spread out, and one care sheet calls them slower than other Porcellio. We will post dated counts here when we have them.
Buying them
Our giant canyons are not for sale yet. We expect to skim the first ones in early 2027. Join the waitlist and we will tell you when they are ready. If you want to start your tub first, the guides below cover substrate and what isopods eat.
Questions people ask
How big do giant canyon isopods get? Field guides list adults to about 15 millimeters. Keepers report 18 to 20 in culture, close to three quarters of an inch.
Do giant canyon isopods roll into a ball? No. They hide and dig.
What humidity do giant canyon isopods need? A gradient with a damp third and a dry rest. They tolerate dry better than most isopods.
Are giant canyon isopods good for beginners? Yes. Keepers call them easy. The one thing they ask for is deep substrate.
How fast do giant canyon isopods breed? Moderate. Faster than zebras and Montenegros, slower than dairy cows. We will post our own counts.
What we use in this tub
The litter is what the colony eats every day. The giant canyons themselves are not for sale yet.
Mixed Hardwood Leaf Litter, Heat-Treated (1 gallon)
$16.99, free shipping
Cover for the dry end and food for the whole tub.
Giant Canyon Isopods (Porcellio dilatatus)
Not for sale yet, early 2027
Our own colony, started September 2026 and still building. Join the waitlist and we will tell you when we can skim it.
Every pack starts in our bins. Ours, not a wholesaler's.