What Do Isopods Eat? A Complete Feeding Guide (UK)

By Kernow Isopods · Truro, Cornwall

Isopods are nature's recyclers, so most of what they need is free: dead leaves and rotting wood. Get those right, add calcium and a little protein, and almost any species will thrive and breed. Here's exactly how we feed our colonies in Cornwall.

The staple: leaf litter

Dead, dry hardwood leaves are the most important food in any isopod tub. They eat them, hide under them and raise their young in them. Keep a thick layer on top of the substrate at all times and top it up as it disappears.

Best leaves: oak, beech, hornbeam and hazel. Oak and beech last longest and are the safest all-rounders.
Collect brown, dry leaves that have fallen naturally, away from roads and sprayed fields.
Bake at about 100 °C for 20 minutes (or freeze for 48 hours) to kill mites and other hitchhikers.
Avoid evergreen and conifer leaves, laurel, yew and anything you can't identify.

Rotting hardwood

Soft, white-rotted hardwood is the second staple. Many species, especially Cubaris, graze the fungus on it, and the babies rely on it. A piece of rotten oak or beech you can crumble with your fingers is perfect. Bake or freeze it like leaves, then bury a piece in the substrate and lay another on top.

Calcium

Isopods are crustaceans and need calcium to moult their shells. Without it, moults fail and colonies stall.

Cuttlebone is the easiest: keep a piece on the surface permanently.
Crushed eggshell (baked) and limestone or chalk chips also work.

Protein (once a week)

A small pinch of protein boosts breeding, especially in Cubaris, and stops colonies turning on their own moults. Too much goes mouldy, so little and often is best.

Fish flakes, dried shrimp, dried mealworms or dried daphnia.
Freeze-dried insects or a little high-protein fish food.
Remove anything that hasn't gone in two or three days.

Fresh food treats

Fresh food is optional, but most species love it. Offer a small piece once or twice a week and remove leftovers before they go mouldy.

Good: carrot, courgette, cucumber, squash, sweet potato, apple, pear, banana (sparingly).
Avoid: citrus, onion, garlic, anything salty, seasoned or cooked in oil.
Wash fruit and veg well, or use organic, to avoid pesticide residue.

How much and how often?

A healthy tub always has leaf litter and wood available, so they're never truly hungry. On top of that, a weekly pinch of protein and the odd piece of veg is plenty for a starter culture. If food disappears overnight, the colony is growing: add more leaf litter and think about splitting the tub.

Quick checklist

Thick layer of baked oak or beech leaves, always.
Rotten hardwood buried and on top.
Cuttlebone on the surface.
A pinch of protein once a week.
Fresh veg as an occasional treat; remove leftovers.

New to isopods? Start with our guide to starting an isopod colony, or browse our beginner isopods.

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