Thai micro crab care
Limnopilos naiyanetri
The Thai micro crab, Limnopilos naiyanetri, is a tiny freshwater crab from Thailand. Its carapace is about one centimetre wide. It lives entirely underwater and uses setae on its legs and claws to collect small particles. Aquarium knowledge remains limited. We therefore avoid an unsupported minimum tank volume or fixed hardness range, and do not claim tankmate matches without controlled species-specific evidence. A mature aquarium, gentle current and fine structure matter more than a falsely precise recipe. Observe feeding and condition closely because the animals are small and easy to overlook.
Plan your aquarium →At a glance
- Temperature
- 22–28 °C
- pH
- 6.5–8.0
- Diet
- Omnivore, Filters small suspended food particles
- Adult size
- Up to 1 cm
- Temperament
- Peaceful
About this species
The species was described from Thailand in 1991. A 2007 taxonomic revision reinstated the genus Limnopilos after it had previously been placed under Hymenicoides. Check the scientific name when buying because trade names such as micro crab can be ambiguous.Natural habitat
Type material is from the Tha Chin River system in Nakhon Pathom Province, Thailand. Aquarium observations describe crabs among water-hyacinth roots and resting on wood or plants. Wild ecology is incompletely studied; aquarium observations are not a full field survey.Aquarium and layout
Use a mature, stable freshwater aquarium with fine plants, moss, wood and sheltered resting places. Gentle flow can carry fine food particles past the crabs; strong flow may make particle collection harder. Guard filter intakes so small crabs and larvae are not drawn in. A reliable minimum tank volume has not been established, so no exact litre figure is given.Water conditions
Sources give broadly overlapping aquarium advice of about 22–28 °C and pH 6.5–8.0. These are husbandry recommendations, not experimentally established tolerance limits. Keep conditions stable, maintain oxygenation and keep ammonia and nitrite undetectable. Evidence is insufficient for a fixed GH or KH range.Behaviour and group size
The Thai micro crab is tiny, fully aquatic and often shy. Aquarium sources describe it as peaceful, but exact combinations with fish and other invertebrates have not been studied well enough. A species-only aquarium avoids the risk of larger animals eating or displacing it. A general label such as “peaceful” does not prove compatibility.Feeding
Fine hairs on the legs and claws collect small suspended particles and microorganisms. Use a mature aquarium with biofilm and offer very small portions of fine food that disperses through the water column. Observe whether the crabs feed and remove leftovers. Excess powdered food can quickly harm water quality. No catalogue product was individually verified as suitable.Breeding
Females carry eggs beneath the abdomen. They hatch into free-swimming zoea larvae. An aquarium publication reports that attempts to rear larvae often fail early; the required conditions remain unclear. Captive breeding should not be presented as easy or guaranteed. Filter intakes and adult crabs may threaten larvae.Keeping with fish
A specialist aquarium source names small Boraras rasboras as potential companions, but individual fish vary. Avoid any fish able to swallow a crab only about one centimetre across; a species-only aquarium remains safest.
Keeping with other invertebrates
Neocaridina shrimp are suitable under conditions: a specialist source reports peaceful cohabitation, but this exact pairing has not been tested in a controlled trial. Java moss is suitable under conditions as fine structure and a perch. Ensure adequate food and keep the moss clean.
Exoskeleton, shell and minerals
Like other crabs, Limnopilos naiyanetri moults. Provide quiet shelters and keep water quality stable. Its specific mineral needs are insufficiently studied; do not add minerals or supplements without evidence. Watch for prolonged difficulty moulting or mortality.Possible problems
Key risks include too little fine food, sudden water changes, strong flow and predation by larger animals. The crabs can be difficult to observe because of their size. Feed sparingly, protect filter intakes and buy only when species identity is clear.Keeping with other species
Cherry shrimp
Suitable with conditionsSuitable under conditions: a specialist aquarium source reports peaceful cohabitation with Neocaridina shrimp. This is not a controlled trial of these exact species. Make sure both animals can access food and observe them.
View species profile →Suitable plants
Java moss
Suitable under conditions: Java moss provides fine structure and perching surfaces; a specialist source specifically recommends it for this crab. Keep the moss clean. The pairing has not been tested in a controlled trial.
- Light
- Low, Moderate
- CO₂
- CO₂ injection not essential
Sources & review
This care guide draws on several specialist sources and was last checked on .
View the sources
- Raffles Bulletin of Zoology / Lee Kong Chian Natural History Museum — Chuang & Ng (1991), Limnopilos naiyanetri, new genus and species
- Zootaxa — Naruse & Ng (2007), On the taxonomy of Hymenicoides and Limnopilos
- Global Biodiversity Information Facility — GBIF Backbone Taxonomy: Limnopilos naiyanetri
- Practical Fishkeeping — Thai micro crab, Limnopilos naiyanetri
- Gensou Aquascaping — Thai Micro Crab Care Guide: Limnopilos naiyanetri
- Aquarium Dietzenbach — Limnopilos naiyanetri species profile