8 Amazing Freshwater Crabs For Your Aquarium

The cosmic water body that surrounds our life-sustaining planet presents us with the most diverse species of exotic creatures, many of which still remain unknown to us.

At present, there are over 228,450 different types of marine species that have been discovered over the course of time; however, marine experts believe that there are as many as 10 million species that are yet to be discovered.

This absurd figure includes almost all types of sea creatures ranging from seaweed to the largest mammal in the world.

Crabs are one such marine species that maintains its distinct characteristics even out the quarter of a million aquatic life forms presently known.

Their distinct claws and hard shells make them an easy target to distinguish from the rest of the other aquatic species. Crabs belong to the family of Decapod Crustaceans, which boats of over 4500 different species of aquatic life forms. 

Freshwater crabs, in specific, refer to the subsidiary species of crabs that live on, well, freshwater. At present, there are over 1,300 different types of freshwater crabs. The diverse availability of such an exotic form of marine life produces some of the most bewildering and awestruck freshwater crabs.

These exotic aquatic creatures find a vast multitude of applications and significance in terms of the ecological, medicinal, and decorative field as well. 

Freshwater crabs naturally possess a generous percentage of protein and carbohydrates, amongst many other vital minerals, and hence, are used as a vital ingredient in many cuisine cultures around the globe. In addition to that, uncooked freshwater crabs are also used for various medicinal purposes in different continents, specifically in Africa, Asia, and Neotropics, as well.

However, due to their distinct and exotic appearance, freshwater crabs make for an adorable aquarium pet.

Freshwater crabs are available in a vast number of sizes and distinct shades of colors as well, making it an extremely head-scratching venture when you are trying to buy the ideal clawed critter for your aquarium.

It is also vital to understand that freshwater crabs are not used simply for enhancing the aesthetic aspect of your aquarium, but can also play a crucial role in keeping the tank clean by consuming the left-over fish food and also for eliminating the waste materials/ residues that are formed every day as well.

Here are eight (8) of the most adorable and awesome freshwater crabs. 

8 Best Aquarium Freshwater Crabs

Fiddler Crabs

Fiddler Crabs

The vast majority of the people have an extremely strict stereotypical physical image of a freshwater crab in which the body is dominated by the shell, and the side fore-arms have distinctly bigger claws. However, this is not the case for a typical Fiddler crab. 

The first thing you will notice about a Male Fiddler crab is its extremely disproportionate claws that give it a unique physical appearance like no other freshwater crabs. The physical dimension of one of the claws is almost equivalent to the size of the crab, whereas the other has a significantly larger and, hence, promotes a more prominent presence. However, female fiddler crabs have claws of the same size.  

The more intriguing aspect of this oversized claw is that it can vary in color ranging from a bright yellow to gold as well. This enhances the aesthetic feature of a fiddler crab even further. Ironically, male fiddler crabs cannot use their major claw for feeding; hence, the female crabs with their proportionate claws are more effective at feeding.  

Another unique feature of a fiddler crab is that they have the tendency to turn light in the night and dark by day as well. This gives you copious numbers of things to look forward to if you have a fiddler crab in your artificial water body enclosure. 

Fiddler crabs by their nature are also considerably small in size and can only grow up to two inches. The temperament level of fiddler crabs is usually categorized as “non-violent/ peaceful,” so you don’t have to worry about your fiddler trying to take down the other aquarium creatures. However, they need constant attention with their feeding and timely cleaning of their environment as well.  They also have a considerably short life span of about 2-3 years only, which means you will have to invest your time taking proper care of it. 

Red Claw Crabs

red claw crab

The Red Claw Crab may be one of the most sought-after freshwater crabs due to their distinct appearance, which is dominated by shades of red color throughout their body, and (of course) they are readily available as well. Red claw crabs are mostly found only in some specific regions, most notably in Asian countries. 

Ironically, Red claw crabs are not a genuine freshwater creature; instead, they thrive ideally on a brackish water body. However, they can survive perfectly on a controlled freshwater enclosure as well by mixing 1-2 tablespoon marine salt per gallon of water. 

Like any other aquarium-compatible marine creatures, Red claw crabs are also small in size and can only grow up to a maximum of 2-4 inches. If kept in an ideal environment (brackish water), Red Claw Crabs can survive up to 5 years, but their lifespan is shortened to about 2 years in a freshwater enclosure. Hence, it is necessary to create an ideal marine environment if you want to ensure it lives up to its maximum lifespan duration. 

 Unlike some specific freshwater crabs, such as the Fiddler crab, Red Claw does not require any extensive maintenance routine. However, they are a natural “climber,” and hence can easily crawl out of the aquarium if they are not monitored regularly. It also helps to keep them in a deep enclosure or cover all the possible exits to avoid such situations. 

Red claw crabs are also notorious for their not-so-friendly attitude towards small fishes and their other male counterparts as well. They have a naturally territorial instinct, which is why keeping two male Red claws in one small aquarium is not recommended. Also, since the Red Claws are naturally Omnivorous, you should be extremely careful with your choice of fishes as well. They should not be bottom dwellers and, most importantly, should be able to sustain low-end brackish water bodies as well.       

Thai Micro Crabs

Thai Micro Crabs

The name is pretty self-explanatory – Thai Micro Crab is one of the smallest types of freshwater crab you can house on your enclosed community tank and is found exclusively in the freshwater body of Thailand. In addition to their miniature size, Thai Micro Crabs also make for one of the friendliest aquatic companions you can pet on your aquarium. Some of its alternate biological names include False Spider Crab, Pill Box Crab, and Limnopilos naiyanetri. 

The maximum carapace size of a Thai Micro crab can vary between the minimum 0.4 inches to the maximum size of 1 inch across the leg span. They are also one of the few crabs that truly qualify as a fully aquatic creature as they can spend their entire lifetime underwater without the need to surface out of the water for a sunbath. 

A typical Thai Micro Crab usually has a brownish-grey appearance, but the color can also vary from a light grey to brownish-orange as well. Some aquarists also believe that Thai Micro Crabs can change the color of their collar hues according to their mood. However, this has not been conclusively proven as of yet.   

Thai Micro Crabs also have an extremely shy and passive physical characteristic, and, hence, they spend most of their time hiding away from their other aquarium companions. They can co-exist peacefully with almost any type of other friendly aquatic companions unless they are omnivorous. 

They also have a distinct bristle-like hair particles that cover the majority of their body. These hairs perform the specific function of trapping small aquatic microorganisms when water passes through it. Also, due to their extremely small physical size, their feeding requirement is also low as well. In fact, they do not require any frequent feeding and can survive on minimal supplemental catering. 

The ideal enclosed environment of a Thai Micro Crab would include a densely decorated aquarium with a copious number of plants and rocks to provide an ideal hiding place for the introvert crab. The usual lifespan of a Thai Micro Crab is sadly very less, and can only live up to 1.5 years. 

Panther Crabs

Panther Crabs

Sounds exotic, doesn’t it? The Panther Crab lives up to its name and is probably one of the most unique and physically-striking crabs you can add to the list of marine companions in your aquarium. Unlike other types of (mostly) friendly freshwater crabs, Panther crabs are not the ideal peaceful types or even the easiest to obtain as well. They are a native of a small Indonesian island called Sulawesi. 

Panther crab gets its names from the fact that it shares a striking resemblance with one of the fiercest and distinctive wild animals with the same name. The crab is distinguished by the black dots that are spread across its entire orange (ish) body. However, the resemblance does not stop there – panther crabs are considerably larger in size and are also notably more aggressive than other usual freshwater marine life forms. This is probably why petting a panther crab is not necessarily recommended, unless you are a professional aquarist. 

They can grow up to a substantial size of up to 3.1 inches (8 cm), which is quite large for a freshwater creature. Panther crabs also have the tendency to feed on other smaller marine life forms, and hence, you need a large tank capacity (at least 80 cm) if you want to really pet it.

Other than feeding off its smaller counterparts, panther crab can also turn against each other, especially males. Hence, it is not a good idea to enclose multiple male panther crabs in a limited space as well. The best way is to keep males and females in pairs to avoid any kind of violent confrontations. 

Panther crabs are also one of the rare crabs that can function totally as a fully aquatic creature, which means they can stay underwater for the entirety of their active marine lifespan. In an ideal freshwater environment, they can survive up to 2-3 years. 

It is also vital to note that they require dense plants or rocky environment inside the enclosure since they need ample hiding space during the vulnerability phase of their molting period. 

Pom-Pom Crabs 

Pom-Pom Crabs 

If you aren’t already familiar with what a Pom-Pom crab is, perhaps it is more effectual if you understand what is Pom-Pom first. Pom-Pom is the generalized name given to a small woolen ball that has been obtained by mixing together a cluster of fabric and used most notably by cheerleaders. Pom-Pom crab gets its name from the strikingly distinct filters on their claws that resemble the conventional pom-pom design.          

Due to their unique appearance, pom-pom crabs are also known by some of its alternate names, most notably, the boxer crab. In reality, the pom-pom like particles on the claw is actually a sea anemone which performs the function of collecting micro food particles such as zooplankton below the deep level of water bodies. 

Although they are one of the most adorable and exquisite types of freshwater crabs, they are not easily found and, hence, are not as common as other types of freshwater crabs you may find in most aquariums. Pom-Pom crabs are generally found exclusively on the Hawaiian Islands only. In fact, it even has its native Hawaiian name called Kumimi pua, which loosely translates to Incredible Flower Crab in conventional English literature. They were even considered and treated as sorcerers in the olden times by the elders due to their distinct claw appearance as well. 

They are also one of the smallest species of freshwater crabs, reaching only up to the maximum size of up to 1.5-2 inches in width (across the leg span). In contradiction to their misleading name tag (boxer crab), they are one of the most peaceful and low-temperament marine creatures that can co-exist with almost any type of other similar and peaceful freshwater marine life forms. Due to their limited offense mechanisms, it is not recommended to put them alongside other omnivore aquatic animals. 

Pom-Pom crabs are also very low-maintenance creatures, which means you don’t have to worry about constant monitoring or cleaning the tank as well. However, they enjoy ample of dense plants and hiding spots, since they are a natural burrowing creature. But they are not necessarily shy and will not hesitate to show off their prized pom-pom like claws day and night as well.                

Vampire Crabs

Vampire Crabs

No, you don’t have to worry about these crabs lurking out of the aquarium to suck your blood dry. Vampire Crabs are one of the most unique and exquisite species of crabs you can add to your aquarium, mainly due to their distinctive physical attributes.

A vampire crab inherits its name due to the unusual glowing yellow eyes, and the vibrant color shades that run throughout its body. The carapace, along with the claws, can take different shades of striking colors from deep purple to neon orange, making them one of the most aesthetically pleasing crabs to look at. They are relatively harder to obtain, as opposed to some of the most common types of freshwater crabs. This makes them an exceptionally rare species to find in aquariums.

Vampire crabs are also not a fully aquatic creature, which means you would have to set up a specialized environment that offers generous dry land area if you want them to live for the maximum stretch of their usual lifespan. However, they require a copious stretch of the freshwater enclosure as well; hence, a paludarium set up consisting of a balanced space between freshwater and dry land is ideal for them. 

Vampire crabs are also relatively small in size as compared to its other counterparts as well. They can grow up to the maximum diameter size of 5-6 cm or 2-2.5 inches across their stretched leg span. They are an omnivore species, which means they can survive on almost anything you throw at them, including frozen food, vegetables, or just any type of fish food you usually get from your supermarket. In addition to that, they can chew on natural vegetations, algae, smaller fish, and shrimps well, making them extremely easy to take care of once you have established an ideal breeding enclosure. 

In an ideal aquarium set up with proper care, a vampire crab can usually live up to 2-3 years. Vampire crabs in contradiction to their name tag are also a peaceful species and can co-exist with its other marine companions without showing any prominent signs of aggression. 

Rainbow Crabs

Rainbow Crabs

Rainbow crabs are exactly as they sound – vibrant and contrast colored crabs that are a treat to look at. They are native to West African coastal areas and rivers and are known popularly for their exquisite blend of colors.

Rainbow crabs usually have a distinct purple to the blue-colored carapace, whereas, the claws/legs have colors ranging from red to bright orange, which makes them one of the most elegant freshwater crabs you can add to your aquarium community. Male rainbow crabs are also known to be more vibrant in color compared to their female counterparts, as well. 

Rainbow crabs, as opposed to other miniature freshwater crabs, are also relatively larger in size and can grow up to a maximum size of 6-8 inches (~15-20 cm) across the width of the carapace.

However, the average size of such vibrant crabs measures only up to 4 inches, which is still a relatively large crab species. Their substantial size means you will have to keep them in an aquarium with generous space to help them move around with limited restrictions. 

Rainbow crabs are not fully aquatic species, which means you will need to incorporate a dry land space in your aquarium to help them take a breather from time to time. They also like to spend most of their leisure time burrowing into the thick sandy ground as well. Hence, it is recommended to provide ample thick sandy floors they can dig into. 

They can survive ideally on both freshwaters as well as brackish water conditions, making them easy to care for as well. Although it is not essential to provide UV lightings, it is a vital element if you want to bring out their bright and vibrant color shades. 

Rainbow crabs, in general, exhibit a non-violent nature, but the males tend to get aggressive when kept together in close proximity. Hence, keeping multiple male rainbow crabs in a limited enclosure is not recommended. 

They are an omnivore and can survive on almost any type of everyday food item you throw at them, including worms, vegetables, fruits, pinkies, fish, crab or turtle pellets, etc. It is also believed that small chunks of cuttlefish are good for their exoskeleton, as well.              

Purple Matano Crabs 

Purple Matano Crab

If you love showing off exquisite pieces of freshwater crabs and fishes on your aquarium, the Purple Matano crab is your ideal marine companion. Dominated by the striking color of the purple carapace and bright yellow legs, these freshwater crabs are an incredible sight to behold. 

Lake Manato is a natural lake located in the South Sulawesi province in Indonesia and is the native home to Purple Manato crabs – hence, the name. They are relatively a larger species of freshwater creatures as well, and their carapace diameter can measure up to the maximum size of 5 inches (~12 cm) in width. In addition to that, they are a naturally extrovert/active marine species, as well. Hence, you require at least a 20-gallon tank capacity to house these adorable marine pets. 

Purple matano crabs are known to exhibit significant aggressive temperament when kept in close proximity with other smaller aquarium crabs and fishes. They are also an expert climber, which means they will not hesitate to climb out through any possible exits. It is, therefore, vital to keep all the openings properly shut to prevent such occurrences. 

They are also amongst the few freshwater crabs that depend entirely on the marine environment, which means you don’t have to carve out a spate dry land. Purple Matano are omnivorous scavengers and, thus, can survive on a wide array of diet plans ranging from frozen foods, tiny bits of vegetables, non-oily fishes, worms, etc. It is also not recommended to keep smaller shrimps or slow fishes alongside purple matano as it can easily turn those innocent marine creatures to food. 

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