Lemon Blue Isopods (Cubaris sp.) for Sale UK

The Cubaris Lemon Blue is one of the most visually striking premium Cubaris in the hobby — a Thai species defined by its bold lemon-yellow body and the blue-tinted inner segments that flash under direct light. The colour combination is genuinely unusual; most isopods don't combine warm and cool tones like this, and the effect when light catches them properly is unmistakable. They've been described as looking like "candy," and the comparison isn't a stretch.

That said, this is not a beginner species. Lemon Blues are slower breeders than most Cubaris, and their famous colouration depends heavily on diet — they will fade without consistent carotenoid-rich feeding. They reward keepers who put in the effort and disappoint those who don't. If you've kept other Cubaris successfully and want a genuine display species, they're one of the best choices available.

Available in groups of 5, 10, or 20. Captive-bred stock from established UK colonies.

Quick Care Summary

• Scientific Name: Cubaris sp. 'Lemon Blue'
• Common Name: Lemon Blue Isopod, Cubaris Lemon Blue
• Family: Armadillidae
• Origin: Thailand and parts of southern China — limestone karst regions near Cubaris sp. 'Jupiter' habitat
• Adult Size: 15–20 mm
• Lifespan: 2–4 years typical
• Difficulty: Medium to High — not for beginners
• Temperature: 21–29°C (70–85°F)
• Humidity: 60–80% with moisture gradient
• Ventilation: Low to medium — humidity retention prioritised
• Behaviour: Conglobates, semi-social, more active than shy Cubaris species
• Breeding: Slow — colony establishment takes 3–4+ months minimum

What Makes Lemon Blue Isopods Special

The visual appeal is the main draw, and it's genuine:

The yellow-blue colour combination is unique. Most isopods are predominantly one colour family — warm browns, oranges, and reds, or cool greys and blacks. Lemon Blues combine bright lemon-yellow with blue-tinted inner pereon segments visible through the exoskeleton. When direct light catches them at the right angle, the blue tones flash against the yellow background — a genuinely striking effect.

Distinctive yellow "skirt". Unlike Jupiter Isopods where yellow forms outlines around each individual segment, Lemon Blues display a continuous yellow band running front-to-back along the body edge. This creates the "skirt" appearance that's diagnostic for the species.

Colours improve with age. Newly arrived specimens often look underwhelming compared to mature, well-fed adults. Given time, proper conditions, and appropriate diet, the colours deepen and the blue tones become more pronounced. Patient keepers are rewarded.

Active and observable. Unlike some shy Cubaris species that hide constantly, Lemon Blues are reasonably active once established. They venture out to forage during dim conditions and don't disappear at the first sign of disturbance. This makes them genuinely viable as display animals rather than cleanup crew you rarely see.

Hard exoskeleton. Lemon Blues have firmer exoskeletons than some softer-bodied Cubaris, which means they're not easily predated in mixed enclosures. This also means they're not suitable as feeders for small reptiles or amphibians — but at this price point, you wouldn't be using them as feeders anyway.

How Lemon Blue Compares to Other Cubaris

If you're choosing between premium Cubaris species, here's how Lemon Blues fit in:

• vs Jupiter Isopods: The closest comparison since both come from the same broader Thai region (Jupiter habitat is reportedly near Lemon Blue habitat in the wild). Jupiters have segment-by-segment yellow outlines on a black body; Lemon Blues have a continuous yellow skirt with blue inner segments. Jupiters are easier to breed and less colour-dependent on diet. Lemon Blues are more visually impressive when properly maintained but more demanding overall.
• vs Panda King: Panda Kings are cheaper, breed faster, and have black-and-white patterning. Lemon Blues have richer colouration but slower breeding and more demanding husbandry. Panda Kings are the better gateway Cubaris; Lemon Blues are a step up.
• vs Rubber Ducky: Rubber Duckies are larger with the iconic ducky-face shell shape. Lemon Blues are smaller but more colourful. Different aesthetic appeals — Rubber Duckies for shape, Lemon Blues for colour.

Browse the full Cubaris collection to compare all options.

The Diet Reality — Why Colour Matters

This is the most important section for anyone considering Lemon Blues. Their colouration isn't fixed — it depends on diet, and it can fade significantly without proper feeding.

The yellow tones come primarily from carotenoid pigments accumulated through diet. Carotenoids are natural plant pigments found in vegetables like carrot, sweet potato, butternut squash, and pumpkin. Isopods can't synthesise these pigments — they get them from food, store them in tissues, and display them through the exoskeleton. Without consistent carotenoid intake, the yellow fades. The blue tones seem less diet-dependent but overall vibrancy still reflects nutritional health.

Practical implication: Lemon Blues need carotenoid-rich foods offered several times weekly, not just occasionally. This is more frequent feeding attention than you'd give to species where colour isn't the main appeal. If you're not willing to maintain this feeding consistency, choose a different species — neglected Lemon Blues look disappointingly muted, like washed-out versions of the photos that drew you to them in the first place.

Setting Up the Enclosure

A 6–10 litre tub or small glass enclosure suits a starter colony of 5–10. Plastic tubs with clip-lock lids work well — they hold humidity better than glass terrariums, and humidity retention matters here.

Ventilation should be low to medium. Lemon Blues tolerate slightly more airflow than strict cave-dwelling species but still need humidity preserved. Small holes on opposite sides of the enclosure provide cross-ventilation without dropping humidity. Avoid wide mesh sections — they dry the enclosure out too quickly. Our accessories collection has appropriate enclosures and small-vent options.

Substrate

Build a layered substrate that matches their Thai limestone karst origins:

Base layer (5–6 cm): Organic topsoil mixed with flake soil for nutrition. Mix in sphagnum peat moss for moisture retention.

Calcium throughout: Generous quantities of crushed limestone mixed throughout the substrate. Lemon Blues come from limestone karst regions and benefit from substrate-level calcium availability, not just placed pieces on top.

Middle layer: Kinshi pieces and rotting white hardwood. Both provide food value and structural complexity. Tropical Cubaris actively feed on fungal-decomposed wood.

Top layer: Generous leaf litter using magnolia leaves for long-lasting cover, bamboo leaf litter for structure, and Asian leaf mix for native Thai/Vietnamese leaves. Add multiple cork bark pieces for hides — Lemon Blues use them actively for shelter and moulting.

Sphagnum moss patches: Place in corners to maintain localised humidity zones without making the entire enclosure too wet.

Humidity and the Moisture Gradient

Maintain humidity at 60–80%. Lemon Blues handle a slightly broader range than some cave-dwelling Cubaris but still need consistent moisture. Mist regularly and ensure the substrate stays damp without being waterlogged.

Create a moisture gradient:

• Damper side (around half the enclosure): Moist substrate with sphagnum moss and damp leaf litter
• Slightly drier side: Drier substrate where they can choose drier conditions if needed

The gradient lets the colony self-regulate. It also helps prevent mould issues that develop in uniformly humid enclosures.

Temperature

21–29°C is the comfort range. They tolerate a reasonable range, but stable conditions matter more than hitting any specific point. Most UK homes provide acceptable temperatures during warmer months; in winter, a low-wattage heat mat on the side of the enclosure (never underneath) connected to a thermostat keeps the colony in the breeding-friendly range. Avoid sustained exposure below 20°C or above 30°C.

Diet — The Critical Section

Diet is where Lemon Blue care most clearly differs from other Cubaris. The colour-maintaining feeding regime isn't optional.

Primary diet (always available):

• Decaying leaf litter — magnolia, oak, beech
• Rotting white hardwood
• Kinshi — fungal-decomposed wood

Carotenoid-rich vegetables (essential — offer 2–3x weekly):

• Carrot — particularly high in beta-carotene
• Sweet potato — orange-fleshed varieties especially
• Butternut squash and pumpkin
• Cucumber as variety
• Sweet pepper (orange or red)

Protein supplementation (1–2x weekly):

• Dried daphnia — high protein, also adds chitin
• Silkworm pupae — high fat for breeding conditioning
• Fish flakes — formulated insect-based protein
• Freeze-dried peas — plant protein with carotenoids built in
• Spirulina — additional carotenoid source

Calcium (always available):

• Cuttlebone permanently in the enclosure
• Limestone mixed into substrate (essential for limestone-karst species)

Repashy supplements: Morning Wood is well-suited to Lemon Blues — calcium-fortified, plant-based, and contains additional carotenoid sources (paprika, marigold flower, calendula). It's one of the few formulated products that supports the colour-maintenance feeding regime.

Bee pollen: Often suggested for Cubaris and worth offering. Some keepers report Lemon Blues take it readily; others report indifference.

Breeding

Lemon Blues are slow breeders, even by Cubaris standards. Set realistic expectations — this is not a species you buy expecting rapid colony growth.

Establishment time: 3–4 months minimum before stable breeding begins. Often longer. Don't panic if your colony isn't producing offspring in the first quarter.

Brood characteristics: Moderate brood sizes when breeding does occur. Population growth is gradual rather than explosive.

Conditions for breeding:

• Stable warm temperatures (22–27°C)
• Consistent humidity (60–80%)
• The full colour-maintaining diet (well-fed colonies breed better than malnourished ones)
• Abundant calcium
• Deep substrate for security and moulting
• Minimal disturbance, especially during establishment
• Larger starter groups (10+) provide better genetic diversity

Patience is essential. Resist constantly checking the enclosure during the first few months. Undisturbed colonies establish faster.

Pair With Springtails

Add a thriving springtail culture from day one. Lemon Blues need consistent humidity, and humid enclosures develop mould without springtail cleanup. Springtails handle frass and microbial growth at a scale isopods can't manage. They coexist peacefully with Lemon Blues and are essential rather than optional.

Who Should Buy Lemon Blue Isopods?

Good choice for:

• Keepers with successful Cubaris experience wanting a genuine display species
• Collectors building a Cubaris collection across visual styles
• Anyone willing to maintain consistent carotenoid-rich feeding
• Keepers who value visual impact and have patience for slow colony growth
• Display setups where appearance matters more than population size

Not ideal for:

• Beginners — start with hardier species first (Dairy Cows, Porcellio scaber) or accessible Cubaris (Panda King, Jupiter)
• Anyone wanting low-maintenance, set-and-forget species
• Keepers expecting fast breeding or population growth
• Reptile/amphibian keepers wanting feeders (their hard exoskeletons make them poor prey, and the price doesn't justify feeder use)
• Anyone unwilling to maintain consistent carotenoid feeding (your animals will fade)

Realistic Expectations

Newly arrived Lemon Blues often look less impressive than the marketing photos. This is normal. Stress from shipping, recent acclimation, and diet variability all affect colour. Given 2–3 months of stable conditions and proper feeding, the colours deepen significantly. Mature, well-fed adults develop richer yellow tones and more visible blue flashing than newly-arrived juveniles.

The flip side: poorly maintained Lemon Blues fade. Without consistent carotenoid intake, the lemon-yellow loses saturation. With inadequate calcium, moulting becomes problematic. Without humidity stability, the colony stresses and stops breeding. They're rewarding for keepers who put in the effort, and they punish neglect more visibly than hardier species.

Building Your Setup — Pairs Well With

For a complete Lemon Blue setup:

• Flake Soil — fermented hardwood substrate base
• Kinshi — mushroom mycelium substrate, biologically appropriate
• Magnolia Leaves — long-lasting primary leaf litter
• Bamboo Leaf Litter — structural leaf cover
• Asian Leaf Mix — premium native Thai leaves
• Cuttlebone — essential calcium for moulting
• Malawi Limestone — essential for cave-origin species; mix into substrate generously
• Repashy Morning Wood — calcium-fortified gel premix with carotenoids built in
• Dried Daphnia — protein with chitin variety
• Freeze-Dried Peas — plant protein with carotenoids
• Springtails — cleanup crew (essential)
• Enclosures & Air Vents — properly humidity-retaining housing

For more on Cubaris species, read our blog post 23 different types of Cubaris isopods you should know about. Browse the full Cubaris collection or all isopods for more options. New keepers should also see our setting up guide for full enclosure walkthroughs.