Cubaris sp. "Miyako" (also sold as Iriomotensis "Miyako" or Japanese Red Edge) is a visually striking isopod from Miyako Island in southern Japan. Their dark body contrasted with vivid reddish-orange skirting and antennae makes them immediately recognisable. Native to the limestone forests of their island home, they share care requirements typical of Cubaris species—high humidity, limited ventilation, and calcium-rich substrates. What sets Miyako apart from many Cubaris is their relative hardiness and more accessible price point, making them a reasonable entry into the Cubaris genus for keepers ready to move beyond beginner species.
A Glimpse
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Origin: Miyako Island, Japan
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Scientific Name: Cubaris sp. "Miyako" (sometimes listed as Cubaris iriomotensis)
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Maintenance required: Low to Medium
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Average Size: 1.2-1.5 cm
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Rarity: Medium to High
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Lifespan: 2-4 years
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Temperature: 20-28°C (68-82°F)
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Ventilation: Low
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Humidity: 70-80%
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Favorite food: Decaying wood, leaf litter, protein sources
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Supplements: Cuttlefish bone, crushed limestone, calcium powder
Cubaris sp. Miyako: Introduction
Miyako Island is a limestone island in the Okinawa Prefecture of southern Japan, characterised by subtropical forests with high humidity and abundant decaying vegetation. The isopods from this island have adapted to these warm, humid conditions with calcium-rich soil—requirements that translate directly into captive care.
The taxonomy of these isopods remains somewhat debated. They're sometimes formally described as Cubaris iriomotensis, though classification discussions continue in the hobby. For practical purposes, "Miyako" identifies this specific locale regardless of the exact species designation.
Miyako isopods are sometimes confused with Cubaris murina "Red Edge" due to similar colouration. While both display reddish-orange edging, they're distinct populations with slightly different appearances upon close inspection. If you're familiar with one, you'll notice differences in the other.
Compared to some premium Cubaris species, Miyako offer attractive colouration at a more accessible price point. They're not the easiest Cubaris to breed prolifically, but they're hardier than some of the more demanding species, making them a sensible stepping stone for keepers wanting to try Cubaris without immediately jumping to the most challenging (and expensive) options.
Cubaris sp. Miyako: Physical Traits and Characteristics
- Adults reach approximately 1.2-1.5 cm
- Dark, almost black body colouration
- Striking reddish-orange colouration on the skirting (edges of each segment)
- Reddish-orange antennae matching the skirt colouration
- Smooth, glossy carapace with attractive sheen
- Capable of conglobation (rolling into a ball) though they don't do so as readily as some species
- Compact, rounded body shape typical of Cubaris
The colour contrast between the dark body and vivid orange edging is genuinely eye-catching. Under good lighting, the glossy carapace adds to their visual appeal.
Behaviour
Cubaris sp. Miyako display typical Cubaris behaviours with some notable characteristics.
Activity patterns: Primarily nocturnal but will venture out during the day in established colonies. They're more likely to be visible in dim lighting conditions.
Conglobation: While capable of rolling into a defensive ball, Miyako don't curl up as readily as some other isopods. They're described as relatively "fearless" compared to more skittish species, often continuing their activities rather than immediately rolling when disturbed.
Burrowing: They're active burrowers and enjoy digging into substrate. This behaviour is important to accommodate—shallow substrate frustrates their natural instincts.
Social behaviour: Peaceful and social. They cluster together comfortably and show no aggression toward each other or other species.
Stress responses: While hardier than some Cubaris, they're still sensitive to environmental changes. Sudden fluctuations in humidity or temperature can cause stress. Minimise handling and avoid frequent enclosure disturbances.
Diet
Miyako isopods have dietary requirements typical of Cubaris species, with emphasis on calcium and protein.
Primary foods:
- Decaying hardwood (essential base food)
- Dried leaf litter (oak, beech, and similar hardwoods)
- Rotting wood in various stages of decay
- Cork bark
Supplementary foods:
- Vegetables: carrot, courgette, sweet potato
- Occasional fruits in small amounts
- Fish flakes or pellets for protein
- Dried shrimp
- Mushrooms (dried or fresh)
Calcium requirements: Higher than many species. Their native limestone island environment means they're adapted to calcium-rich conditions. Provide cuttlefish bone, crushed limestone, or calcium powder as constant supplements. Inadequate calcium leads to moulting problems and poor health.
Protein requirements: Also elevated compared to some species. Regular protein supplementation through fish flakes, dried shrimp, or similar sources supports healthy growth and successful breeding.
Feeding approach: Maintain a constant supply of leaf litter and decaying wood. Supplement with vegetables and protein sources every few days. Offer small portions initially and observe consumption to avoid overfeeding and potential pest attraction.
Cubaris sp. Miyako: Breeding
Miyako isopods breed reasonably well in captivity, though they're not as prolific as some beginner species.
Breeding difficulty: Medium. They're not the fastest breeders, but with proper conditions, colonies grow steadily. Don't expect explosive population growth—Cubaris generally reproduce more slowly than Porcellio or Armadillidium species.
Breeding requirements:
- Stable high humidity (70-80%)
- Consistent warm temperatures (22-26°C ideal for breeding)
- Abundant calcium availability
- Adequate protein in diet
- Deep substrate for security
- Minimal disturbance
Brood characteristics: Females carry developing young in their marsupium and release fully formed juveniles. Brood sizes are moderate.
Colony establishment: Starting with a group of 10+ individuals provides the best foundation for a breeding colony. This ensures genetic diversity and a good chance of having both sexes represented. Patience is required—Cubaris colonies develop over months rather than weeks.
Tips for success: Stability is key. Avoid frequent substrate changes, temperature fluctuations, or other disturbances. Once conditions are right, let the colony establish without interference. Checking constantly and digging through substrate to count individuals causes stress that inhibits breeding.
Cubaris sp. Miyako: Habitat Setup
Creating appropriate conditions means replicating their humid, limestone forest environment.
Enclosure: A plastic container or glass terrarium with limited ventilation. Unlike species requiring airflow, Cubaris need humidity retention. A container with minimal ventilation holes or a glass enclosure with restricted airflow works well. Starting size of 6-10 litres suits a starter colony, with larger enclosures for growing populations.
If using a glass display enclosure, ensure it retains humidity effectively. The ability to observe these attractive isopods is a genuine benefit of glass, but humidity management becomes the priority.
Substrate: Deep substrate is essential—these are active burrowers. Provide 10-15cm (4-6 inches) minimum:
- Organic topsoil as a base (pesticide-free)
- Sphagnum peat moss mixed throughout
- Crushed limestone or calcium powder (generous amounts—10% or more)
- Leaf litter layered on top
- Decaying hardwood pieces
- Sphagnum moss patches for moisture retention
The calcium content is particularly important given their limestone island origins. Don't skimp on limestone or calcium supplements in the substrate mix.
Humidity: High humidity is essential—70-80%. These are not isopods that tolerate dry conditions:
- Maintain consistently moist (not waterlogged) substrate
- Use sphagnum moss patches to hold moisture
- Mist regularly to maintain humidity
- Provide a moisture gradient with slightly drier and wetter areas
- Limited ventilation helps retain humidity
Monitor humidity levels, especially in warm weather when evaporation increases. Dry conditions stress Cubaris quickly.
Ventilation: Low ventilation. Unlike Mediterranean Porcellio species, Cubaris from humid Asian environments need restricted airflow. Too much ventilation drops humidity to harmful levels. Small ventilation holes or gaps rather than mesh lids work better.
Balance is needed—some air exchange prevents stagnation and mould, but prioritise humidity retention over airflow.
Lighting: They prefer dim conditions. Avoid bright, direct lighting on the enclosure. Subdued lighting or positioning away from direct light sources keeps them comfortable and more likely to be active and visible.
Décor and hides:
- Cork bark pieces and tubes
- Flat bark sections
- Limestone pieces (functional and aesthetic)
- Leaf litter coverage
- Sphagnum moss patches
- Egg cartons or coconut shells as additional hides
Provide multiple hiding options throughout. Their burrowing nature means much activity happens below the surface, but surface hides encourage visible activity.
Temperature: 20-28°C (68-82°F). They tolerate a reasonable range but avoid extremes. Room temperature in most UK homes works during warmer months; supplemental heating may be needed in winter to maintain optimal conditions.
Bioactive Use
Cubaris sp. Miyako can function in bioactive setups meeting their humidity requirements.
Best suited for:
- Tropical bioactive enclosures
- Humid vivarium setups
- Dart frog enclosures
- Tropical gecko habitats
- Any high-humidity bioactive system
Advantages:
- Attractive appearance adds visual interest
- Effective decomposers in humid environments
- Peaceful coexistence with other cleanup crew species
- Interesting behaviour to observe
Considerations:
- Not suitable for arid or semi-arid setups
- Slower breeding than standard cleanup crew species
- Higher value than typical bioactive isopods
- Require consistent high humidity that not all setups provide
Less ideal for:
- Dry or Mediterranean-style enclosures
- Setups with significant humidity fluctuation
- Situations requiring rapid population growth
- Budget cleanup crew applications
Suitability
Cubaris sp. Miyako suit keepers ready to move beyond beginner species into the Cubaris genus.
Good choice for:
- Keepers with basic isopod experience wanting to try Cubaris
- Those maintaining humid tropical setups
- Collectors seeking attractive species at accessible prices
- Bioactive enthusiasts with high-humidity enclosures
- Anyone wanting visually striking isopods without premium Cubaris prices
Not ideal for:
- Complete beginners (start with P. scaber or similar first)
- Arid or low-humidity setups
- Keepers wanting rapid colony growth
- Those unable to maintain consistent humidity
Care level: Low to medium difficulty. They're among the more forgiving Cubaris species, but still require attention to humidity and substrate depth that beginner species don't demand. Keepers comfortable maintaining stable humid conditions will find them straightforward. Those accustomed to hardy, dry-tolerant species may need to adjust their approach.
Compared to other Cubaris: More accessible than premium species like Rubber Ducky or Panda King in both price and difficulty. They offer genuine Cubaris appeal—the colouration, the behaviour, the care requirements—without the steep learning curve and cost of the most demanding species. A sensible choice for testing whether Cubaris keeping suits you before investing in rarer options.
Expectations: Expect attractive, interesting isopods that reward proper care with steady (not explosive) colony growth. Their colouration genuinely impresses, and their behaviour—particularly the burrowing and relative boldness—adds interest beyond just visual appeal. Don't expect them to thrive with neglect or fluctuating conditions, but do expect success with consistent, appropriate husbandry.
