This is Cubaris sp. "Lemon Blue" - a premium Thai Cubaris with striking yellow and blue colouration. The current description mentions coconut fibre in the substrate section which I'll remove. At £175 for 10, this is a premium species. I'll write a comprehensive description with your realistic tone.
Cubaris sp. "Lemon Blue" is a premium Thai Cubaris renowned for its striking bicoloured appearance—bright lemon yellow body with blue-tinged inner segments that flash in the light. Native to Thailand and parts of China, they're among the more visually impressive Cubaris species available, though their colouration requires dietary attention to maintain. They're not a beginner species despite some claims—their slower breeding, colour maintenance requirements, and sensitivity to conditions make them better suited to keepers with Cubaris experience. For those ready for the commitment, few isopods match their visual impact when properly cared for.
A Glimpse
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Origin: Thailand, China
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Scientific Name: Cubaris sp. "Lemon Blue"
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Maintenance required: Medium to High
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Average Size: 1.5-2 cm
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Rarity: High
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Lifespan: 2-4 years
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Temperature: 21-29°C (70-85°F)
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Ventilation: Low to Medium
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Humidity: 60-80%
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Favorite food: Leaf litter, carrot, sweet potato, butternut squash
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Supplements: Cuttlefish bone, calcium powder, bee pollen
Cubaris sp. Lemon Blue: Introduction
Lemon Blue isopods originate from tropical and temperate regions of Thailand and China. Their natural habitat provides the warm, humid conditions they require, though they're somewhat more tolerant of humidity variation than some cave-dwelling Cubaris species.
The "Lemon Blue" name accurately describes their appearance: a bright lemon-yellow body with blue colouration visible on the inner pereon segments. When light catches them at the right angle, the blue tones flash attractively against the yellow background. The overall effect is genuinely eye-catching—they're described as looking like "candy" and the comparison isn't unreasonable.
However, there's an important caveat: their vibrant colouration isn't guaranteed. Lemon Blues can fade or lose colour intensity without appropriate diet. Maintaining their striking appearance requires consistent feeding of carotenoid-rich foods. This isn't a species you can neglect and expect to remain visually impressive.
They're also slower breeders than many Cubaris species. Colony establishment takes time—expect 3-4 months minimum before seeing stable breeding. This combination of colour maintenance needs and slower reproduction means they require more ongoing attention than hardier species.
The seller's own notes are honest: "We find these not as forgiving as some other isopods so not something for a beginner as they also require a little more maintenance." This is accurate. They're a species for keepers who've successfully maintained other Cubaris and are ready for something more demanding.
Cubaris sp. Lemon Blue: Physical Traits and Characteristics
- Adults reach approximately 1.5-2 cm
- Bright lemon-yellow body colouration (when properly maintained)
- Blue-tinged inner pereon segments visible through the exoskeleton
- The blue colour "flashes" when light hits at certain angles
- Hard exoskeleton (not suitable as feeder isopods)
- Capable of conglobation (rolling into a defensive ball)
- Colouration deepens and improves with age in well-maintained specimens
- Colour can fade with inadequate diet or poor conditions
The visual impact depends significantly on care quality. Well-maintained Lemon Blues are genuinely stunning; neglected ones can look disappointingly muted.
Behaviour
Cubaris sp. Lemon Blue display some distinctive behavioural traits.
Social behaviour: Semi-social. Unlike strongly social isopods that cluster tightly, Lemon Blues are more tolerant of individual space. They can live alone without obvious distress, though they do fine in groups. As populations grow, they become more active and visible within their enclosure.
Activity patterns: Active species once established. They move around their enclosure more than some shy Cubaris species. However, they may hide around other creatures or when disturbed.
Temperament: Bold but non-aggressive. They're described as confident pets that don't display aggression toward each other or tank mates.
Response to disturbance: May hide initially but generally less skittish than some Cubaris species once established.
Conglobation: Capable of rolling into a defensive ball when threatened, though they don't do so as readily as some species.
Diet
Diet is particularly important for Lemon Blues—their signature colouration depends on it.
Primary foods:
- Decaying leaf litter (oak, beech, and similar hardwoods)
- Rotting hardwood
- Decaying organic matter
- Cork bark
Colour-enhancing foods (essential):
- Carrot (excellent source of carotenoids)
- Sweet potato
- Butternut squash
- Cucumber
- Foods containing astaxanthin
- Foods containing carotene
Supplementary foods:
- Fish flakes and fish food
- Dried shrimp (gammarus)
- Spirulina
- Fresh fruits (banana, mango)
- Dried fruit pieces
- Bee pollen
- Insect jelly
- Lichen
Calcium: Essential for healthy moulting. Provide cuttlefish bone, crushed limestone, oyster shell, or calcium powder as constant supplements.
Protein: Regular protein supplementation through fish flakes, dried shrimp, or bat guano supports healthy growth and breeding.
Colour maintenance: This cannot be overstated: inconsistent feeding causes colour loss. Regular offerings of carrot, sweet potato, and butternut squash maintain and deepen their lemon-yellow colouration. The blue tones seem less diet-dependent but overall vibrancy requires nutritional attention. Well-fed specimens develop richer, deeper colours as they age; neglected ones fade.
Feeding approach: More frequent feeding than some species may be needed to maintain colouration. Ensure colour-enhancing foods are offered several times weekly, not just occasionally.
Cubaris sp. Lemon Blue: Breeding
Lemon Blues are slower breeders than many Cubaris species—set expectations accordingly.
Breeding rate: Slow compared to other Cubaris. The seller notes they breed slower than similar species like Ambers even under identical conditions. Don't expect rapid population growth.
Colony establishment: Expect 3-4 months minimum before seeing stable breeding activity. This is slower than many popular Cubaris species.
Breeding requirements:
- Appropriate humidity (60-80%)
- Stable warm temperatures (22-27°C ideal)
- Consistent, colour-maintaining diet
- Adequate calcium
- Deep substrate for security
- Minimal disturbance
Brood characteristics: Moderate brood sizes when breeding does occur. Population growth is gradual rather than explosive.
Tips for success: Patience is essential. Provide optimal conditions consistently rather than expecting quick results. Starting with larger groups (10+) provides better breeding potential. Maintain excellent nutrition—healthy, well-fed isopods breed more reliably than stressed or malnourished ones.
Cubaris sp. Lemon Blue: Habitat Setup
Creating appropriate conditions balances humidity with adequate ventilation.
Enclosure: A container or terrarium with controlled ventilation. They need humidity retention but tolerate slightly more airflow than some cave-dwelling Cubaris. Plastic containers with limited ventilation holes or glass terrariums work well. Size should accommodate their active nature—they appreciate space to move.
Substrate: Deep substrate supporting humidity and their natural behaviours:
- Organic topsoil as a base (pesticide-free)
- Sphagnum peat moss mixed throughout for moisture retention
- Crushed limestone or calcium powder incorporated generously
- Hardwood leaf litter layered on top
- Decaying hardwood pieces
- Sphagnum moss patches for additional moisture retention
Depth of 8-10cm allows burrowing and maintains stable humidity.
Humidity: 60-80%—they handle a broader range than some Cubaris but still need consistent moisture:
- Maintain moist substrate throughout
- Provide moisture gradient (drier and damper areas)
- Mist regularly to maintain humidity
- Sphagnum moss patches help retain moisture
- Monitor conditions—they're less forgiving of extremes than hardy species
Ventilation: Low to medium. They tolerate slightly more airflow than strict cave-dwelling species but still need humidity retention prioritised. Small ventilation holes rather than fully open mesh.
Lighting: Avoid direct light. Keep enclosures in shaded or dimly lit locations. They're not as strictly photophobic as some species but prefer subdued lighting.
Décor and hides:
- Cork bark pieces and tubes (essential hiding spots)
- Leaf litter coverage
- Sphagnum moss patches
- Decaying wood pieces
- Multiple hiding options throughout
Temperature: 21-29°C (70-85°F). They tolerate a reasonable range but avoid extremes. Room temperature in heated UK homes typically works, with attention during cold spells.
Bioactive Use
Lemon Blues can function in bioactive setups but considerations apply.
Best suited for:
- Tropical bioactive enclosures
- Display vivariums where visual impact matters
- Humid setups with moderate conditions
Advantages:
- Striking visual appeal adds genuine interest
- Active behaviour makes them more visible than shy species
- Hard exoskeletons mean they're not easily predated
Considerations:
- Premium pricing makes them expensive as purely functional cleanup crew
- Slower breeding limits population recovery
- Colour maintenance needs mean they're not "set and forget"
- Hard exoskeletons make them unsuitable as feeders
Not suitable as feeders: Their hard exoskeletons make them a poor choice for feeding to other animals. If you need feeder isopods, choose softer species bred for that purpose.
Suitability
Cubaris sp. Lemon Blue suit experienced keepers wanting visually impressive isopods.
Good choice for:
- Keepers with successful Cubaris experience wanting something special
- Collectors seeking premium, visually striking species
- Those willing to commit to colour-maintaining feeding regimes
- Display setups where appearance matters
- Patient keepers not expecting rapid colony growth
Not ideal for:
- Beginners (gain experience with hardier Cubaris first)
- Keepers wanting low-maintenance species
- Those expecting rapid breeding
- Budget-focused bioactive cleanup
- Anyone unwilling to maintain consistent feeding schedules
Care level: Medium to high difficulty. They're described as "not as forgiving" as other isopods, and this is accurate. Their needs aren't extreme, but they require more consistent attention than hardy species. The colour maintenance aspect adds ongoing work that simpler species don't demand.
Realistic expectations: Don't expect the vibrant colours shown in photos to maintain themselves automatically. Expect to actively work at keeping them looking their best through regular carotenoid-rich feeding. Expect slow breeding and patient colony development. Expect a rewarding species if you put in the effort—and a disappointing one if you don't.
Value assessment: At £175 for 10, they're a significant investment. The value lies in their genuine visual appeal when properly maintained—few isopods look as striking as healthy, well-fed Lemon Blues. However, that visual impact requires ongoing commitment. They're worth the price for keepers who'll provide that care; they're an expensive disappointment for those who won't.
The seller's honest observation: "When we first got them we were not too excited when we saw them but after settling in the colours really changed and seem to also improve with age." This is realistic—newly arrived specimens often look underwhelming. Given time, proper conditions, and appropriate diet, they develop into the stunning animals their reputation suggests. Patience and care are rewarded.
