The Thai micro crab is one of the rarest fully aquatic freshwater crabs. They have tiny, hairy, silver-colored bodies that can be perfect for tankmates or peaceful invertebrates like shrimp.
Thai micro crabs require very little care with perfection, and they do not have many requirements. Here you go with all the required information for Thai microcrabs.
Quick overview of Thai micro crab
Name
The Thai micro crab is also known as the false spider crab, pill-box crab, laos micro spider crab, micro crab, freshwater micro crab, or freshwater spider crab the scientific name being limnopilos naiyanetri.
Natural habitat and distribution
First, they were discovered in the roots of water hyacinths in the Chin River, Thailand. Due to their limited presence and being fully aquatic crabs, Thai micro crabs were not found outside of the river Chin in Thailand.
Temperament
The micro Thai crab is a very peaceful crab that can live with tankmates in harmony, as their small size does not allow them to fight. With that being said, they can be easy targets of aggressive fish and other crabs.
| Size | The carapace can reach up to 1 cm, with a leg span of 2.5 cm (1 inch) |
| Color | The Thai micro crab is semi-translucent, with silver, gray, to light brown. |
| Lifespan | 1–1.5 in captivity |
| Diet | Omnivorous |
| Sleeping | Nocturnal |
| Breeding | Very hard |
| Care Level | very easy |
| Optimal temperature | 72° – 82° F (22° – 28° C) |
| Micro crabs aquarium | Freshwater aquarium |
Some interesting facts about Thai micro crab
- From legs to carapace, the entire body of the Thai micro crab is covered with bristles, which help them catch floating food particles.
- Their appearance resembles more a spider in the water than a crab; that’s why they are often referred to as false spider crabs.
- This crab was introduced and discovered and introduced in recent years (1991 to 2007, the phase of introduction and specification), which makes it a relatively new crab compared to other crab species.
- Differentiating between female and male Thai microcrabs can be very difficult because of their tiny appearance. Some aquarists observed that the males have narrow and pointy bodies, and the females have relatively rounded bodies.
Thai micro crab care
Thai micro crabs are not considered beginner-friendly crabs; due to their extremely small body, some shops recommend them only for experienced aquarists. But I think this is a misconception; the care is very easy with proper knowledge, making it a beginner-friendly crab.
Tank setup for micro thai crab
Setting up the enclosure in a proper way means trying their best to mimic their natural habitat.
Tank size—Thai micro spider crab
The tiny bodies of Thai micro spider crabs do not need a large tank size like other crabs. They can perform very well with 5-6 in a group; a minimum of 5 gallons of tank will be needed for this little group. Set up the size with the number of crabs accordingly.
They shouldn’t be kept in too big a tank, as they will be very hard to spot.
Substrate for freshwater micro/spider crabs
Don’t go too complicated with the substrate; you can even use a bare-bottom tank (a tank with no substrate) as substrate plays no role for Thai micro crabs because most of the time they will hide in crevices of plants and stones. The bare-bottom tank will also help you spot it in the clean tank.
However, I’m not saying substrate will be bad. You can use gravel (the grains should be small) as substrate.
- Take an aquarium filter bag and fill it with substrate.
- Place the bag into the bottom of the tank.
- Cover the substrate with bigger stones, or you can use black crushed lava gravel [black because it will be easy to find the white crab and is considered suitable for freshwater aquariums]
Decoration and hiding places
Micro Thai crabs will need a lot of hiding places, meaning really a lot. Sometimes you may find the tank empty, as they love to hide.
Place some aquarium stones (the darker ones are suggested) and maybe one clay pot or other things with your creativity, like a moss cave and a driftwood.
Plants are very crucial for Thai micro crabs, especially aquarium plants like the water hyacinths, wendt’s water trumpet, alternanthera sp, and anubias barteri. And then fill the tank with water.
Thai micro crab water parameters and temperature
Ensure your micro crabs have a temperature between 72° and 82° F (22° and 28° C). An aquarium heater is preferred to warm the temperature of water in aquariums.
The pH and KH should be kept between 6.5 and 7.3 and 6 and 15.
Thai micro crabs do not have much flexibility with water changes, so ensure the water condition is right.
Thai micro crab feeding—Thai micro crab diet
Thai micro crabs are nocturnal animals, meaning they can eat anything. They will eat small plant particles and microorganisms. You can feed them a small amount of commercial food like fish flakes or pellets. Don’t degrade the water quality by giving a lot of food. Nothing complicated with feeding; they can eat the same food as their tankmates.
Though they are omnivores, sometimes they may act opportunistically carnivorous.
Thai micro crab tank mates
Choose small, peaceful fish that are their size or smaller than them, as bigger species will see them as food. You can take dwarf shrimp as an example. The best tankmates will be their own species. Here is a list of a few tank mates:
- Tetras
- Bee shrimp
- Guppies
- neocaridina shrimp
- Small barbs
- Micro-Rasboras
- Bamboo shrimp
- Kuhli loaches
- Vampire shrimp
- Cherry shrimp
- Bloodfin tetra
- Pygmy Corydoras
- Small snails
Thai micro crab breeding
Breeding Thai micro crabs is way more difficult than other crabs. No successful breeding is reported, meaning you have to be pessimistic about their breeding and wait until someone discovers the right condition and process. Discovering their breeding will make them more available and stop the black market from catching them from the wild, meaning the Thai micro crab you have was transported from the river Chin, Thailand, to the US. This is a sad part, though.
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Frequently Asked Questions
Can Thai micro crabs live with shrimp?
Yes, Thai micro crabs can live peacefully with shrimp like cherry shrimp, bee shrimp, and neocaridina. Both species are gentle and occupy different spaces, making them ideal tankmates.
Do Thai micro crabs breed in captivity?
No successful breeding has been reported in captivity. They are extremely hard to breed due to unknown larval stages and specific environmental needs that haven’t been replicated in tanks yet.
Do Thai micro crabs eat shrimp?
They do not hunt shrimp, but may scavenge on already dead or dying ones. While they’re omnivorous, they aren’t aggressive enough to harm live shrimp.
How many Thai micro crabs per gallon?
You can safely keep 5–6 Thai micro crabs in a 5-gallon tank. For each additional 1–2 crabs, add 1–2 gallons to ensure enough space and hiding spots.
How to breed Thai micro crabs?
Currently, there’s no known method for breeding Thai micro crabs in captivity. Attempts have failed, and the full breeding cycle remains a mystery. Most crabs in the hobby are wild-caught.
Are Thai micro crabs hard to keep?
Not at all! They’re actually easy to care for if you have the right setup—stable water parameters, gentle tankmates, and lots of hiding places make them beginner-friendly.
How big do Thai micro crabs get?
Their carapace grows up to 1 cm (about 0.4 inches) with a leg span of about 2.5 cm (1 inch). They are one of the smallest freshwater crabs in the world.
Are Thai micro crabs rare?
Yes, they’re considered rare because they’ve only been found in the Chin River in Thailand. All Thai micro crabs in the pet trade are wild-caught, adding to their rarity.
Can Thai micro crabs live with fish?
Yes, but only with small, peaceful fish like tetras, pygmy corydoras, or micro-rasboras. Avoid aggressive or larger fish, which may see the micro crab as food.
Can Thai micro crabs escape?
They’re not known for escaping like some larger crabs, but to be safe, always use a secure tank lid. Their tiny size makes them vulnerable if they crawl out.
How long do Thai micro crabs live?
In captivity, Thai micro crabs typically live 1 to 1.5 years with proper care. Wild ones may live slightly longer, but captive lifespan is still relatively short.
Are micro crabs aggressive?
No, Thai micro crabs are completely peaceful and non-aggressive. They won’t attack fish or shrimp and mostly keep to themselves.
What do you feed Thai micro crabs?
They eat biofilm, algae, leftover fish food, and sinking pellets. You can also offer powdered shrimp food or crushed fish flakes in small amounts.
Can Thai micro crabs live in brackish water?
No, Thai micro crabs are fully freshwater crabs. They cannot tolerate brackish or salty water and must be kept in stable, clean freshwater conditions.
