The Thai Micro Crab is a fully aquatic, extremely small freshwater crab native to a single river system (the Tha Chin river) in Thailand. They are exceptionally peaceful and lack standard defensive capabilities. Instead of hunting, they use tiny hairs on their claws to catch detritus and filter-feed biofilm. Due to their miniature size and incredibly shy nature, they must be kept with peaceful nano tank mates (like Neocaridina shrimp) or in a species-only setup to prevent predation.
Thai Micro Crab At a Glance
Thai Micro Crab Tank Requirements
Will Thai Micro Crab fit in your tank?
Care guides tell you what Thai Micro Crab needs, the next question is whether your tank can safely provide it. Test Thai Micro Crab against your tank size, maintenance needs, and the fish you already keep before you buy.
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Thai Micro Crab Water Parameters
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Thai Micro Crab Temperament & Compatibility
Thai Micro Crab Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Standard
The standard Thai Micro Crab. Best kept in groups in densely planted tanks. They are highly nocturnal and will spend most of the day hiding among roots (especially floating plants like Water Lettuce) and leaf litter.
Same care requirements as the base species
Also known as: Wild Type
Thai Micro Crab Care Guide Summary
The Thai Micro Crab, scientifically known as Limnopilos naiyanetri, belongs to the Invertebrates family group. Adults reach a maximum size of approximately 1.5 cm and have a depressed body shape with a slow growth rate. Classified as peaceful, this species primarily occupies the bottom zone of the aquarium and produces a low level of biological waste.
To thrive, the Thai Micro Crab requires a freshwater only aquarium with a minimum volume of 19 litres and a tank length of at least 30 cm. Water temperature should be maintained between 22°C and 28°C, with a pH range of 6.5–8 and a general hardness of 6–15 dGH. A low water flow is preferred.
Due to its specialist needs, the Thai Micro Crab is best suited for fishkeepers who can provide a carefully planned setup. The Thai Micro Crab is typically available in one standard form.
Thai Micro Crab Habitat Setup
When setting up an aquarium for the Thai Micro Crab, a low water flow best suits their natural preferences. Because this species occupies the bottom zone, the aquarium layout should prioritise sufficient floor space with hiding spots among rocks, wood, or dense planting. Useful additions include leaf litter or blackwater tannins to replicate their natural soft-water habitat, dense planting to provide cover, break sightlines, and reduce stress, and floating plants to diffuse overhead light and create shaded areas.
Thai Micro Crab Compatibility Notes
Classified as peaceful, the Thai Micro Crab is adaptable and can be kept singly or in a small group, offering flexibility when planning a community tank. When choosing tankmates, boisterous or fast-moving tankmates may cause this species undue stress. Selecting tankmates that favour different water layers from the bottom zone can help reduce competition and territorial overlap.
Thai Micro Crab Recommended Tank Sizes
Standard aquarium sizes that meet the minimum volume and length requirements for Thai Micro Crab.
5 Gallon
10 Gallon Standard
15 Gallon Standard
20 Gallon High
20 Gallon Long
29 Gallon Standard
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Frequently Asked Questions About Thai Micro Crab
How big does Thai Micro Crab get?
Thai Micro Crab (Limnopilos naiyanetri) typically reaches a maximum adult size of approximately 1.5 cm. They have a depressed body shape and a slow growth rate.
What tank size does Thai Micro Crab need?
A minimum aquarium volume of 19 litres and a tank length of at least 30 cm are recommended for Thai Micro Crab. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Thai Micro Crab need?
Thai Micro Crab thrives in freshwater only conditions with a temperature range of 22–28°C, a pH between 6.5 and 8, and a general hardness of 6–15 dGH. A low water flow is preferred.
Is Thai Micro Crab peaceful or aggressive?
Thai Micro Crab is classified as peaceful with an aggression score of 0 out of 10. They are generally well-suited to peaceful community tanks.
Can Thai Micro Crab live alone?
Yes, Thai Micro Crab can be kept singly or in a group. They are flexible and adapt well to both setups.
Does Thai Micro Crab have any special tank requirements?
Yes. Thai Micro Crab benefits from plants - densely covered, plants - floating, and leaf litter/blackwater in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Top Tank Mates for Thai Micro Crab
These fish are strong compatibility matches for Thai Micro Crab based on water preferences, temperament, adult size, and tank behavior.
Garnet Tetra
Hemigrammus pulcher
Ideal Tank MatesDwarf Rasbora
Boraras maculatus
Ideal Tank MatesDwarf Pencilfish
Nannostomus marginatus
Ideal Tank MatesGlowlight Tetra
Hemigrammus erythrozonus
Ideal Tank MatesMarbled Hatchetfish
Carnegiella strigata
Ideal Tank MatesGlass Catfish
Kryptopterus vitreolus
Ideal Tank MatesPlants That Suit Thai Micro Crab
These plants pair well with Thai Micro Crab based on shared water preferences, layout fit, and how likely they are to hold up in the same aquarium.
Amazon Frogbit
Limnobium laevigatum
Asian Watergrass
Hygroryza aristata
Asian Watermoss
Salvinia cucullata
Carolina Mosquito Fern
Azolla caroliniana
Common Duckweed
Lemna minor
Crystalwort
Riccia fluitans
Fish Similar to Thai Micro Crab
Phuket Loach
Schistura robertsi
The Phuket Loach is a small, active stone loach native to fast-flowing, clear streams in the Malay Peninsula and southern Thailand. Like most Schistura species, they are highly territorial bottom-dwellers that require highly oxygenated water with moderate to high flow. They should be kept in setups with smooth river stones to break lines of sight and minimize aggression.
Panther Crab
Parathelphusa pantherina
A striking, fully aquatic freshwater crab endemic to Lake Matano in Sulawesi, Indonesia. Recognizable by its pale yellow-orange body covered in dark panther-like spots. They are opportunistic scavengers and predators that will hunt snails, shrimp, and bottom-dwelling or sleeping fish. They are notorious escape artists and require a very tight-fitting lid. Unlike many crabs, they do not require a land area, though they need plenty of underwater rock caves.
Nana Rasbora
Microdevario nana
A true micro-fish endemic to Myanmar, the Nana Rasbora rarely exceeds 1.5cm (0.6 inches). They exhibit a translucent yellowish body with a subtle iridescent blue lateral stripe and a distinct black blotch on the dorsal fin. Due to their minute size, they are completely peaceful, highly shrimp-safe, and must be kept in schools of at least 6-8 in densely planted, mature aquariums. Providing leaf litter and dim lighting will help them feel secure.
Malaya Shrimp
Caridina sp. "Malaya"
A unique and highly variable dwarf shrimp native to Southeast Asia. Unlike most dwarf shrimp, Malaya Shrimp are a low-order species, meaning their eggs hatch into tiny larvae rather than fully-formed shrimplets. However, unlike Amano Shrimp, these larvae do not require saltwater or brackish conditions; they metamorphose completely in freshwater. They are peaceful, active scavengers and excellent algae eaters that come in a wide array of colors including red, blue, green, brown, and clear.
Shortbarbel Pangasius
Pangasius micronemus
A massive, highly active riverine catfish native to Southeast Asia. Like its cousin the Iridescent Shark, it is a nervous and skittish swimmer prone to panicking and injuring itself on tank glass. Due to its enormous adult size of up to 1 meter (39 inches), it is strictly suited for only the largest custom aquariums, indoor ponds, or public aquaria. It is an opportunistic predator that will consume any tank mate small enough to fit in its large mouth.
Glass Catfish
Kryptopterus vitreolus
A highly unique, completely transparent catfish from Thailand. Unlike most catfish, they are mid-water swimmers that require being kept in schools to feel secure. They are incredibly peaceful and easily outcompeted for food. They require stable water parameters and dim lighting or shaded areas provided by floating plants.