Thai Micro Crab Aquarium Comprehensive Care Guide: Tips for a Thriving Habitat

Thai micro crabs are fascinating little creatures that can be a fantastic addition to your aquatic ecosystem. With the right care, they’ll thrive and become a fascinating focal point.

In this article, we’ll explore Thai micro crab care essentials, from water quality and temperature to tank size and dietary needs.

Thai Micro Crab – Taxonomy 

Thai micro crabs are freshwater crustaceans that are scientifically known as Limnopilos naiyanetri. They belong to the family Parathelphusidae, which includes various micro crab species, though Thai micro crabs are the most popular ones.

Thai micro crabs can blend into their surroundings, including living plants or aquarium substrate.

Fun Fact: Thai micro crabs are the smallest freshwater crabs, reaching about 0.39 inches (1 cm) in diameter. This makes them a popular choice for nano aquarium setups. 

by Sean Murray (CC BY-SA 2.0)

Where Do Thai Micro Crabs Come From?

Thai micro crabs, or False Spider Crabs, are native to the Tha Chin River in the Nakhon Pathom Province of Thailand.

Although they were first discovered in 1991, this river remains the only known habitat for these tiny creatures.

What Is The Habitat Of Thai Micro Crabs In The Wild? 

These crabs are fully aquatic and spend their entire lives underwater. Micro crabs are well-adapted to living in slow-moving water, where they can efficiently capture microorganisms and food particles using the hairs on their legs and claws. 

by Sean Murray (CC BY-SA 2.0)

What Do Thai Micro Crabs Look Like?

Thai micro crabs have a unique appearance, with translucent shells that make them challenging to spot among aquatic vegetation.

They’re so small––measuring only about 0.39 inches (1 cm) in size––that they blend in quite easily with their environment.

They have long, spindly legs that they use for navigating their aquatic surroundings. Thai micro crabs also have unique pincer-like appendages called chelipeds, which are proportionally larger than their body size. They use these for feeding and self-defense. 

They have hair-like structures called setae, which cover their legs and chelipeds. These hairs help them forage for food by capturing tiny particles and microorganisms.

by Sean Murray (CC BY-SA 2.0)

Basic Care Requirements

The ideal tank for Thai micro crabs is at least 5 gallons, and should include lots of plants, driftwood, and hiding spots since these tiny crabs are quite shy.

Keeping water parameters consistent is vital. Aim for a water temperature between 72-82℉ (22-28℃) and ensure that you use proper filtration and perform regular water changes as they are sensitive to ammonia and nitrate levels.

Thai micro crabs prefer slightly acidic to neutral conditions.

What Do Thai Micro Crabs Like To Eat?

Feeding Thai micro crabs is fairly simple. They are natural scavengers that eat biofilm, algae, and any decomposing materials in the tank. 

They enjoy both plant-based and protein-rich foods, meaning you can use small portions of fish pellets or shrimp pellets, as well as algae wafers, which provide them with essential vitamins and nutrients.

As a protein-rich option, mosquito larvae can be a great treat. You can also diversify their diet with blanched vegetables like zucchini, spinach, and cucumber and occasional treats like bloodworms or daphnia. 

When it comes to feeding Thai micro crabs, variety and moderation are key. Experiment with different food options and adjust the feeding schedule based on your crabs’ needs. 

by Sean Murray (CC BY-SA 2.0)

Feeding Schedule

Overfeeding Thai micro crabs can lead to poor water quality and health issues. To keep my crabs happy and healthy, I generally feed them small portions two to three times per week. This allows them to rely on their natural foraging skills and promotes a cleaner tank environment. 

Be sure to remove any uneaten food after a couple of hours to minimize water pollution. 

How Do Thai Micro Crabs Behave?

Thai Micro crabs are nocturnal. They tend to hide among plants and other natural decor during the day. At night, they become more active, venturing out of their hiding spots to search for food.

They prefer dwellng in areas of the tank with high densities of algae and other similar sources of sustenance. This scavenging behavior not only provides them with a rich source of nutrients but also helps keep the tank cleaner.

Tank Mates

Thai Micro Crabs exhibit impressive compatibility, and aren’t aggressive. This peaceful nature, along with their preference for staying in groups of five or six, allows them to thrive in community tanks.

Which Tankmates Are Good For Thai Micro Crabs?

Good tank mates for Thai micro crabs include: 

  • Neocaridina shrimp, which are similar in size and temperament
  • Ghost shrimp, another type of shrimp that gets along well with micro crabs 
  • Snails such as Ramshorn snails, Nerite snails, and Mystery snails
  • Peaceful schooling fish like Pygmy Corydoras and Neon Tetras

Which Tankmates Should I Avoid For Thai Micro Crabs?

It’s better to avoid keeping certain species with Thai micro crabs due to compatibility issues. Troublesome tank mates are usually more aggressive, predatory, or simply too large for the tiny crabs. Here are some that are best to avoid:

  • Bettas can be aggressive or territorial, which may stress or injure the delicate, little micro crabs. Although some Bettas are more peaceful than others, monitoring their behavior closely is essential
  • Goldfish might eat or harm the micro crabs
  • Cichlids and Angelfish are known for their territorial and aggressive behaviors
  • Larger catfish could see the micro crabs as a food source

Overall, I find Thai Micro Crabs to be delightful additions to any peaceful aquarium setup. 

How Do Thai Micro Crabs Breed?

To breed Thai micro crabs, you’ll need both males and females. Males usually have longer legs, while females have a broader abdomen to carry their eggs. 

After the crabs mate, fertilization occurs internally. The male transfers sperm to the female via gonopods. The female stores the eggs in her pleon (abdomen).

As the larvae hatch, they remain in their mother’s care. The female carries them until they are independent and able to survive on their own. 

How Do Thai Micro Crabs Molt? 

Molting is when crabs shed their old exoskeleton and grow a new one. While it’s a natural process, it can be stressful for the crabs. To support the process, and make the crabs feel secure, provide hiding spots like small caves or dense plants. 

It’s also a good idea to supplement their diet with calcium-rich foods like cuttlebone pieces to help promote a healthy molting process. Keep water conditions stable, as rapid fluctuations in temperature or water quality may lead to complications during molt. 

Which Plants Can I Use In A Tank For Thai Micro Crabs?

In my experience, plants that work well for Thai micro crabs include Anubias, Java Moss, and Java Ferns. 

They love having plenty of hiding spots, so plant densely and add floating plants like Duckweed and Water Lettuce to provide more cover and make the crabs feel secure. 

Pro Tip: In addition to plants, add some driftwood, rocks, and other decorations to provide more hiding places for your Thai micro crabs. 

Thai Micro Crab FAQs

Are Thai Micro Crabs Fully Aquatic? 

Yes, they are fully aquatic species and can live their entire lives underwater.

Do Thai Micro Crabs Live In Freshwater Or Saltwater? 

Thai micro crabs are freshwater creatures that prefer slightly acidic to neutral conditions. 

Can Thai Micro Crabs Live With Fish? 

Yes, but I recommend keeping them with small, peaceful fish that won’t try to eat them. 

How Many Thai Micro Crabs Should Be Kept Together? 

Ideally, you should keep at least three to four Thai micro crabs together to encourage socializing. 

How Many Thai Micro Crabs Can You Ideally Have In A 5-Gallon Tank? 

You can keep around six micro crabs in a five-gallon aquarium. 

Can Thai Micro Crabs Live With Shrimp? 

Yes, as both species are generally peaceful and have similar tank requirements. 

Can Thai Micro Crabs Live With Cherry Shrimps? 

Yes, they can live harmoniously with cherry shrimps in the same tank. 

Will Thai Micro Crabs Eat Snails? 

No, they typically don’t eat snails. 

Will Thai Micro Crabs Eat Algae? 

Yes, they can help in consuming some algae in the tank, as they graze on biofilm. 

Are Thai Micro Crabs Nocturnal? 

Yes, Thai micro crabs are more active at night and hide during the day.


We hope this article has inspired you to give Thai micro crabs a try. They’re easy to care for, fun to watch, and compatible with many other peaceful species.

If you liked this article, you might find intersting our articles about Panther crabs , Vampire crabs, Fiddler crabs and Red claw crabs.

About the author

Hi, I am Alex.
My passion is aquariums. I am especially drawn to betta fish. I love experimenting, learning, researching, and writing about them.

You can find the articles I wrote here

Leave a Comment