Ardentiella - previously classified as Merulanella until the 2025 taxonomic revision - is a genus of premium tropical isopods that's become increasingly popular in the UK hobby. Worth being clear about the name change upfront: if you've seen these called Merulanella in older sources, that's the same group of isopods. PostPods's collection is listed as "Ardentiella (ex Merulanella)" to reflect the current taxonomy while remaining searchable for keepers who learnt the old name.
What Are Ardentiella?
Ardentiella is a genus of terrestrial isopods, classified within the family Armadillidae (the tropical pill bug family). Despite being in a pill bug family, worth knowing: Ardentiella can roll but seldom do. The 2025 authors say the genus 'only rarely' uses its ability to conglobate and behaves as a runner instead, so expect them to flatten or run when threatened. This is a common point of confusion for keepers expecting pill bug behaviour from all Armadillidae species.
Key characteristics:
- Adult size - 10-15mm typical, some species reaching 20mm
- Body shape - relatively flat, distinctly different from rounded conglobators
- Colouration - varies widely by species; includes striking patterns and bright colours
- Behaviour - moderately active, less secretive than Cubaris but more reserved than Porcellio
Browse our Ardentiella (ex Merulanella) collection for current UK stock.
Geographic Origin
Ardentiella species are native to Southeast Asia - particularly Vietnam, Thailand, and surrounding regions. This is important context that's sometimes confused in older sources: they're NOT from the Americas. The Southeast Asian forest floor habitat shapes their husbandry requirements significantly.
Native habitats feature:
- Warm, humid conditions
- Decaying leaf litter and rotting hardwood as primary food sources
- Forest floor microclimates with shelter from direct sun
- Calcium-rich substrate in limestone-based regions
Husbandry Requirements
Temperature
Cooler than their tropical origin suggests:
- Range - 19-26°C, best at about 20-23°C
- Above 26°C - stress and deaths rise, so summer heat is the main temperature risk
- Heat mats - not needed, and a common way to lose them
A heated British room suits them. Keep the enclosure out of the sun and away from radiators, and plan for a July heatwave rather than a January night.
Humidity
Moderate to high, and never stagnant:
- Target - 60-75%
- Humidity gradient - a damper end and a drier end let isopods self-regulate
- Maintenance - regular misting with proper cross-flow ventilation
- Critical - avoid stagnant air, which causes respiratory issues and mould
Substrate
Important to get right for Ardentiella:
- Base layer - flake soil and organic topsoil, 5-8cm deep
- Calcium additions - crushed limestone or shell pieces mixed in
- Top layer - generous oak, beech, or magnolia leaf litter
- Decaying hardwood pieces - essential dietary component
- Cuttlebone - always available as additional calcium source
- Sphagnum moss patches - for humidity retention and microhabitat
Browse our accessories collection for substrate components, leaf litter, and cuttlebone.
Enclosure
- Size - minimum 5-10 litres for a starter colony (10-15 isopods)
- Ventilation - cross-flow ventilation essential
- Layout - humidity gradient, multiple hiding places, vertical surfaces if possible
- Visibility - moderately active during low-light conditions, more visible than Cubaris
Diet
Straightforward with appropriate variety:
Staple Foods
- Leaf litter - oak, beech, magnolia (essential foundation)
- Decaying hardwood - central dietary component
- Cuttlebone or crushed shells - always-available calcium source
Supplementary Foods
- Vegetable scraps - sweet potato, carrot, cucumber (in moderation)
- Fish flake or shrimp pellet - occasional protein, sparingly (weekly or less)
- Specialised isopod foods - Repashy or similar formulations as supplements
Key principle: variety over quantity. Remove uneaten fresh foods before they spoil.
Reproduction
Like all isopods, female Ardentiella carry fertilised eggs in a marsupium (brood pouch). The young (mancae) emerge as miniature versions of adults rather than going through dramatic metamorphosis.
- Brood time - typically 21-35 days depending on temperature
- Brood size - small, usually 5-15 mancae per brood
- Breeding frequency - moderate (slower than common species but faster than premium Cubaris)
- Maturity - around 6-9 months to breeding age
- Colony growth - moderate pace; takes patience but more reliable than premium Cubaris
Honest Difficulty Assessment
Ardentiella sit in the intermediate-to-advanced tier:
- Not beginner-friendly - they need humid air and strong airflow at the same time
- More forgiving than premium Cubaris - like Rubber Duckies they aren't, but easier than most premium tropicals
- Best for keepers with 6+ months experience - after succeeding with Powder Orange, Dairy Cow, or accessible Cubaris
- Premium pricing reflects rarity - worth budgeting for serious commitment
Related Genera Worth Knowing About
UK keepers interested in Ardentiella often progress to or from related genera, most of which want more warmth than Ardentiella:
- Cubaris - tropical Asian premium genus including Rubber Ducky, Panda King variants, Pak Chong. Browse our Cubaris collection
- Troglodillo - cave-dwelling tropical species. Browse our Troglodillo collection
- Filippinodillo - Filipino premium species
- Nesodillo (the Shiro Utsuri) and other premium Asian genera
Worth being clear: Trachelipus trilobatus (Trilobite Isopod), Pink Panda King, and Cubaris murina are different genera from Ardentiella, despite sometimes being grouped loosely with premium tropical species in marketing content. Each genus has its own care requirements and characteristics.
Sourcing Ardentiella in the UK
Worth being honest about availability:
- Specialist UK breeders - most reliable source for established lineages
- New lines - newer species appear in new arrivals as UK breeders establish them
- Captive-bred preferred - established UK colonies are settled animals with a known husbandry history
- Live arrival guarantees - standard from reputable UK suppliers
Common Problems
Colony Decline
Usually traces back to humidity issues - either too dry (dehydration stress) or too wet without ventilation (respiratory issues, mould). Check ventilation and substrate moisture if you see numbers dropping.
Slow Breeding
Several possible causes:
- Temperature outside their range (especially too warm)
- Insufficient calcium for egg production
- Inadequate dietary variety
- Recent colony stress
- Natural moderate breeding pace - patience required
Visible Stress Behaviour
Excessive surface activity during daytime, refusal to feed, or congregation in one corner often indicates conditions need adjustment. Worth troubleshooting humidity and temperature first.
The Honest Summary
Ardentiella (formerly Merulanella) are:
- Southeast Asian in origin - Vietnam, Thailand, surrounding regions
- 10-15mm typical size - moderately sized hobby isopods
- Rarely roll - despite being in the pill bug family, they can conglobate but seldom bother
- Intermediate-to-advanced level - not beginner isopods, but more accessible than premium Cubaris
- Cool, humid, airy husbandry - 19-26°C, 60-75% humidity, strong cross-ventilation, no heat mat
- Worth knowing the name change - Merulanella → Ardentiella following the 2025 taxonomic revision
For keepers ready to move beyond basic species, Ardentiella offer a distinctive hobby experience without the demanding requirements of premium Cubaris. Browse our Ardentiella collection for current UK stock, or our new arrivals for the latest additions to our range.
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