Rubber Ducky Isopod

Looks how to spot one

Exoskeleton

A small, heavily armoured isopod with a rounded, convex body. The head, viewed from the front, has a dark, rounded shape that resembles the face and bill of a rubber duck toy. The body is vivid yellow to orange with contrasting dark markings, and it can roll into a tight ball when disturbed.21

Personality what they are like

Rubber Ducky isopods are shy and secretive, preferring to stay hidden under bark or in substrate. They are nocturnal and crepuscular, most active during low light. They are docile and not aggressive, but they do not form bonds with keepers. They may roll into a ball when stressed and should be handled minimally.415

Daily activity how busy a day looks

Low activity needs; they are display animals best observed at quiet moments. They do not require exercise or interaction. Provide hiding spots and a stable environment to encourage natural behaviour.61

Grooming and care the hands-on bits

Minimal grooming needed. Keep the enclosure clean by replacing substrate when about a third has become frass, as acidity can rise quickly. Avoid frequent handling; when necessary, do so gently and briefly.41

Home where they are happiest

Keep in a terrarium with deep, nutritious, limestone-rich substrate. Maintain temperature around 22-28°C and humidity 70-85%, with a damp end and good cross-ventilation. Provide hardwood leaf litter, decaying wood, and bark for hiding. Ensure a calcium source is always available. Escape-proof the enclosure with fine mesh, as young can climb glass. They are sensitive to high acidity, so avoid acidic conditions.142

Food basics what goes in the bowl

Omnivorous detritivore. Feed a variety of decaying hardwood leaves, rotten wood, fresh vegetables (courgette, cucumber, sweet potato) in small portions 1-2 times weekly, and protein supplements such as fish flakes, dried shrimp, or freeze-dried bloodworm 1-2 times per week. Always provide a calcium source.14

Company who they like around

Gregarious and live in groups, but not socially complex. They are not suitable for frequent handling and do not bond with keepers. They should be kept separate from other animals to avoid stress or conflict. They are not venomous or illegal to keep, but they are delicate and best for experienced keepers.15

The story where it all began

Rubber Ducky isopods are a colour and pattern variety of an undescribed Cubaris species from Thailand. They were discovered in limestone caves around 2017 and quickly became popular in the hobby due to their unique duck-like face. They reached European captive-breeding networks shortly after, and became established in the UK within a few years. Unlike the plain species, which is not formally described, the Rubber Ducky variety is distinguished by its vivid yellow body and dark head marking that resembles a rubber duck toy. This variety is intermediate to advanced in care, requiring stable warm, humid conditions.172

Recognised by the official bits

Hobby trade name

Not formally described scientifically; known only as Cubaris sp. "Rubber Ducky".1

Popularity High among isopod enthusiasts, credited with popularising the Cubaris hobby.7