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.
At a Glance
Tank Requirements
Water Parameters
Temperament & Compatibility
Available 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 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. To replicate their natural habitat, the tank should include plants - densely covered, plants - floating, and leaf litter/blackwater.
Thai Micro Crab can be kept singly or in a group, making them flexible additions to most setups. Keepers should be aware that this species is primarily active at night or during twilight hours. The Thai Micro Crab is typically available in one standard form.
Similar Species
Dwarf Pea Puffer
Carinotetraodon travancoricus
The Dwarf Pea Puffer is a tiny, fully freshwater pufferfish native to India. Despite their cute appearance, they are fierce micropredators and notorious fin-nippers. Modern husbandry standards strongly dictate they are highly social and must be kept in species-only shoals of 6 or more in heavily planted aquariums to disperse aggression and reduce stress. They require a steady diet of small snails and live/frozen foods.
Siamese Algae Eater
Crossocheilus oblongus
Famous for being one of the few freshwater fish that actively consumes Black Beard Algae (BBA). A torpedo-shaped, active bottom-to-midwater swimmer native to Southeast Asian streams. True Siamese Algae Eaters feature a distinct black horizontal stripe that extends all the way through the tail fin. As they mature, they can become lazy, preferring prepared foods over algae, and may occasionally chase other bottom dwellers.
Least Killifish (Heterandria)
Heterandria formosa
Despite its common name, the Least Killifish is actually one of the smallest livebearing fish in the world, belonging to the Poeciliidae family, not the killifish family. Native to the southeastern United States, they are incredibly peaceful and perfect for nano tanks. Unlike most livebearers, they exhibit 'superfoetation', meaning females drop 1-2 fry every few days rather than a large single brood.
Amano Shrimp
Caridina multidentata
A highly popular, industrious freshwater shrimp renowned for its unmatched algae-eating abilities. Popularized by aquascaper Takashi Amano, they are significantly larger and hardier than most dwarf shrimp (like Cherry Shrimp). They are notorious food-thieves during feeding time and excellent escape artists, requiring a tight-fitting lid. Their larvae require saltwater to develop, so they will not overpopulate in a freshwater aquarium.
Cherry Shrimp
Neocaridina davidi
One of the most popular and hardy freshwater invertebrates in the hobby. They come in a rainbow of selectively bred colors. They are excellent scavengers and algae eaters, perfect for nano planted tanks. They are completely peaceful and have a negligible bioload, though they are highly vulnerable to predation by almost any fish with a mouth large enough to eat them.
Betta (Siamese Fighting Fish)
Betta splendens
The Siamese Fighting Fish is an aquarium icon known for its labyrinth organ (allowing air breathing) and vivid colors. While hardy, they require heated, filtered water (24-30°C). Males are solitary and fiercely territorial. Females are generally less ornate but can be kept in 'sororities' with strict precautions (minimum 5 females in 75L+).