Freshwater crabs are one of the most popular species in aquariums today. If you’re considering adding these incredible creatures to your home, there’s a lot more to learn about them than just what they look like!
These little fellows are quick and easy to care for, but need a lot of space in the home. They average 1-4 inches in size with some varieties reaching 6 or more. All freshwater crabs love climbing, exploring, and hiding so make sure you provide your pet crab plenty of room!
Crabs are notorious for escaping from their aquariums. They’ve earned a reputation as the Harry Houdinis of the crab world! Freshwater Crabs can be very entertaining too, however – many owners derive lots of amusement and enjoyment from them. If you do get one as an addition to your tank, they will certainly bring color and character into your Aquarium.
Overview

Scientists have a lot to learn about freshwater crabs despite the extraordinary number of them in the world. There are approximately 1300 species, but scientists only know well-known facts such as that they belong to eight different families or that some live on land and others underwater (or both).
With the exception of freshwater crabs that can be found in tropical and subtropical regions, these animals are often referred to as narrow endemics. This is because they live only in certain areas or ecosystems with no chance for migration elsewhere due to their living environments being threatened by human activity.
There are a wide variety of different species of freshwater crabs all around the world, but new research is raising concerns about how many may be disappearing. Field and lab studies indicate that up to ⅙ or more than ½ (½) million out of 2,155 known crab species worldwide might have been lost in recent years due to habitat loss from pollution and overharvesting by humans for food purposes .
Unlike their marine counterparts, freshwater crabs give birth to fewer offspring. One result of this is that mother freshwater crabs are more attentive and caring towards their young (in comparison to other types of crab).
Freshwater crabs can breathe air, but they still need to spend some of their time in the water. They have a pseudo-lung which evolved as they adapted to living on land and most freshwater crabs are unable to live out of fresh or salt water for more than a few days at best.
These freshwater crabs are every bit as interesting and unique as their saltwater kin. Some specimens have very large claws or vivid colors, while others prefer a more docile lifestyle that is better suited for children’s aquariums. The one thing they all need to survive? A perfect environment with plenty of space!
Popular Types of Freshwater Crabs
Vampire Crab

These tiny crabs are the perfect addition to any aquarium – and they come in a variety of colors.
The Vampire Crab gets its name from their vivid purple color, which can be used as an accent for your tank; it also has nocturnal tendencies like most vampires!
If you’re worried about being able to keep these little guys alive when housing them with other fish or crustaceans, don’t worry: Vampires have more aggression than many freshwater crabs so you’ll feel confident that yours will survive.
It’s worth noting that the vampire crab might prey on smaller fish. They may also become prey themselves to bigger fish.
Red Claw Crab

These tiny, red-clawed freshwater crabs are called “micro” crabs because of their small size.
They have a tendency to dehydrate so they need access to fresh water and clean saltwater tanks when placed in an aquarium or pond (which is where most people find them).
Micro Crabs can be aggressive with other crustaceans too – especially if there’s not enough space for both populations!
Panther Crab

These crabs are often referred to as leopard crabs. They have a beautiful and unique panther-like pattern that makes them stand out from other types of crab!
Those who own these little beauties report more aggressiveness than the average variety but they also live up to 2 or 3 years in captivity with proper care.
Gold Claw Crab

Fiddler crabs are small crustaceans with one very distinct feature: a large, distinctive claw.
Sometimes called the “golden crab” for its color and larger size, this is their main claim to fame – that would be enough if it stopped there though!
These critters have also been known as plant destroyers because they will eat any nearby vegetation in salt water or fresh water alike.
Rainbow Land Crab

The blue crab is a large freshwater crustacean that can grow to more than 8 inches in size.
They have striking coloring and are usually found living near the ocean or coastline where they scavenge for food on shorelines, reefs, and seagrass beds.
These colorful crabs do well in both saltwater as well as fresh water habitats due to their ability to regulate salinity levels. Which closely mimic those of its natural habitat but will require larger tanks when kept inland.
It has been known to display cannibalistic tendencies after being exposed previously while housed with other smaller species such as shrimp early on during development stages.
Thai Micro Crab

Have a hard time finding something to do in your small apartment? Why not get yourself the perfect pet for living space: the tiny Thai Micro Crab!
With an extremely thin body width of only 0.4 inches, this is great crab for those with very limited living spaces.
These crabs have camouflage bodies which makes them easy to hide.
Freshwater Hermit Crab

As long as they are able to submerge and come out of water when they want, freshwater hermit crabs do not need an aquatic environment.
In fact, some people keep them in bowls with a couple inches of distilled or purified fresh water.
They live well together but have high humidity requirements because their shells will eventually dry up if it is too low.
Matano Crab

The Matano crab is a freshwater crustacean from Indonesia that has beautiful purple scales.
They are quite large, averaging 3-5 inches in length and require higher temperatures than other crabs which makes them perfect for an indoor aquarium!
Thai Devil Crab

The Thai Devil Crab is a very colorful little crab with an extremely non-aggressive disposition.
They will need some dry areas of their habitat, which they often use to eat and hide in.
Try using plants around the area for them since crabs are known to do this as well!
Behavior Of Freshwater Crabs
Although they are primarily scavengers, freshwater crabs can also be considered predators.
These nocturnal creatures spend a lot of their time hidden and climbing in order to explore new territory.
Did you know that freshwater crabs are excellent escape artists? They will often take advantage of the tiniest hole in your aquarium, so make sure it’s escape-proof! Many owners can recount funny moments they have caught their crabs trying to find a way out.
There are many different types of freshwater crabs, but most aren’t very aggressive. Some species will attack other animals that enter their territory and threaten them while others stay mostly on the defensive.
Appearance
From the violet-hued Vampire Crab to the distinctive fiddler crab, freshwater crabs are a diverse group with many beautiful colors and patterns.
The most notable is undoubtedly the Panther Crabs which come in such leopard-like patterning that can be seen from far away.
These types of animals deserve more attention because they play an essential role in their ecosystems as scavengers
Habitat
Freshwater crabs are surprisingly diverse and live in a vast range of habitats.
They thrive the best when their habitat is stable, but many freshwater crab populations struggle to survive as we continue developing our natural resources for human consumption.
We need to work hard with these aquatic animals before it’s too late so that they can continue living alongside us!
Surprisingly, freshwater crabs come from all over the world – there isn’t just one type of environment where you’ll find them lurking about! The majority lives around bogs or swamps which help maintain an appropriate temperature year round; however some areas only receive rain during certain seasons (or never).
Tank Conditions
If you want a healthy and well-adjusted crab, it’s important to replicate their natural habitat as closely as possible.
Fortunately for the modern hobbyist, plenty of reliable research is available online in forums or groups devoted specifically to hobbies like yours.
Take advantage of these resources when researching your pet crabs’ needs so that they can live an authentic life full of adventure!
There is a wide variety of freshwater crabs, all with their individual needs.
For instance, some need an adequate space to swim around in while others require safety from predators or threats such as pollution and contamination.
All these requirements are important for the overall health of any crab population.
One of the most important things to have in a habitat for your pet is plenty of stones and terrestrial areas, logs, and decor (organic or commercial) which serve as hunting grounds that provide safety.
A quality pet store will often carry many interesting options you can use for this purpose so long as it’s safe!
Plus they’ll also need plants – make sure there are several types within reach from ground level up where animals like to climb; these should be placed near water but not too close since salinity levels must remain appropriate.
Finally ensure clean water with proper PH levels by checking droppings on occasion
What size tank do Freshwater Crabs need?
Freshwater crabs require a lot of room, five or more gallons. They also need ample dry areas for resting because their freshwater environment is not fully aquatic and they can drown if it’s too wet.
If you intend to house more than one crab, then be sure that they each have adequate space. This can easily happen if your aquarium is large enough!
If you want a bigger tank for housing multiple crabs, make sure the water and sand are always clean so everyone in there has an excellent environment without any disease-causing bacteria or parasites.
How many can you have in the same tank?
If you’re going to keep more than one freshwater crab, it is advised that not more than one live in a square foot.
Naturally, the bigger your aquarium needs to be based on how many crabs there are.
Not all types of freshwater crabs get along with other aquatic lifeforms of their same species but they can coexist peacefully if given enough space and food variety.
Freshwater Crab Tank Mates
Why should you worry about compatibility when it comes to freshwater crabs?
It all depends on the type of crab. Some can live with snails, while others will just want to eat them!
You’ll have to be careful in deciding whether or not fish are ok for your tank as certain types prey on crabs.
Some crab species are territorial and will fight with one another. If you provide an inadequate space for crabs, it is likely they will attack each other in order to defend their territory.
They may also get aggressive if there are more males than females of the same species available which can lead to appendage damage or death!
Diet
As omnivores, you have many different options when it comes to feeding your freshwater crabs.
You can feed them nutrient-rich bloodworms and fresh vegetables or some of their favorite seafood like brine shrimp and seaweed as well!
Be sure that any frozen food is fully thawed before serving for the best results.
To ensure crabs are getting the nutrition they need, you must take certain steps.
One such step is to allow food on top of your tank’s floor and not feed them from the side.
This way other fish or creatures won’t steal their meal before it reaches its destination!
Freshwater Crab Care Guide
- You always want to make sure your freshwater crabs have enough space in their aquarium.This includes the overall size of their habitat, as well as sufficient land for them to walk on and explore.
Many freshwater crabs will spend half of each day out of water so they’ll need a good amount of terrestrial area just like us! A standard recommendation is 2 parts aquatic-to-1 part terrene (or about 50% land).
- PH levels are very important so make sure you do monitor these.To keep your crabs healthy, make sure you clean the water often. This will prevent impurities in the water.
- As already mentioned you want to make sure your freshwater crabs food does sink to the bottom.This will prevent other fish from getting it and them becoming hungry.
- Add some excitement to your crabs home.They want to be able to explore, so add things such as logs, sand, decor and even plants.
Since they love to hide and climb, this will keep them exploring for hours.
- Make sure your crab has plenty of places to hide. This is even more important when they molt their shell, as they become vulnerable.Shedding their shell does only happen a few times in their life.
Daily Checks
It is recommended that on a daily basis you check the temperature of the water.
If it’s too hot or too cold then this can cause distress to your crab. Keep it in the range of 72-82 degrees Fahrenheit.
Check your filtration to make sure that it is filtering out any impurities from your tank water.
Finally, keep an eye on your crabs. They should be bright in color and very active. If they look dull and sluggish then they might be poorly or molting their shell.
Weekly Checks
On a weekly basis you should do some PH tests. This is going to allow you to monitor the quality of the water in the tank.
Monthly/Bi-Monthly Checks
To help keep the water fresh you should change 10-30% of the water. This only needs to be done monthly or bi-monthly if it doesn’t get too bad.
Breeding
It is incredibly hard to breed freshwater crabs, unless you are experienced then I wouldn’t recommend attempting it.
They are well-known to be not very good at breeding when in captivity.
So Should You Get Freshwater Crabs For Your Aquarium?
I love freshwater crabs. So I would certainly recommend it if you can.
The colors on them are incredible and watching them explore can be really enjoyable.
They are easy to look after, which is why I often recommend them.
Crabs can make a great addition to an aquarium that has some fish species. They offer a whole different perspective to your aquarium.
Watching them climbing, hiding or even at times trying to escape.
Hopefully this guide has helped to give you some ideas on whether or not freshwater crabs are suitable for you and your aquarium.
FAQ
Do freshwater crabs suffer from diseases?
They can get common diseases such as Salmonella and Atypical Mycobacterium. Its important that children and pregnant women are careful as these diseases spread if the crabs are handled.
What’s the lifespan of freshwater crabs?
The lifespan is on average 3 years, although this does depend on the species.
What can I do if my freshwater crab has lost an appendage?
You can help with healing by using an iodine supplement. The appendage can regenerate and regrow sometimes. The iodine supplement will also help with this.
How big do freshwater crabs get?
It depends on the species but on average 1-4 inches, although some are bigger.
What type of water should I fill my freshwater aquarium with?
Freshwater crabs should not come into contact with chlorine. So you should never use tap water. Instead, make sure you use only filtered water.
How do I know if my freshwater crab is molting?
Usually, they will be less active, they won’t be exploring as much and they might even be eating less. In some cases, their color might also look a little dull.
Does direct sunlight harm crabs
It can do yes, so try and keep your aquarium out of direct sunlight.

Hey! I’m Charles. I have always wanted a fish tank but found them confusing. It wasn’t until I turned a room into an office that I started looking into how to set up my own Aquarium. I have spent countless hours/days/weeks learning, now I want to share what I’ve learnt with you.