Crabs are one of the most fascinating creatures you have in your aquarium. We understand that it may not seem conventional or be your first choice, but diversifying your aquarium is not the worst idea. If you really want to build a natural ecosystem in your aquarium and try and include a plethora of different species, then we would like you to consider the option of Fiddler Crab.
To help you understand how you can grow one in your home, we are presenting before you their care guide. We are going to talk about their eating habits, their tank requirements, their appearance their behaviour, their breeding, and much more in our comprehensive guide. So, stick around.
Care Guide of Fiddler Crab
Fiddler Crabs are incredibly popular among aquarists who love hosting invertebrates in their aquarium. This is heavily due to the fact that they are extremely easy to take care of and are amusing to watch.
Members of the Ocypodidae family, these crustaceans are also known as Calling Crabs. They are mostly seen in the Indo-Pacific, Eastern Pacific and the Atlantic region. Fiddler Crabs spend their time enjoying salt marshes, mangroves, muddy and sandy beaches. Usually, coastal habitats with brackish water are what they prefer.
One of the major mistakes that people make (partly due to the misinformation given by pet store owners) is that they keep them in freshwater tanks. This severely affects their health and decreases their lifespan. We will explain this more in the tank requirement section later. If taken care of, they can live for 2-3 years.
Appearance of Fiddler Crab
A great aspect of their appearance is that they are small in size. As such, they wouldn’t take up too much space in your tank. They usually measure 2-3” (5-8 cm). Sexual dimorphism is pretty prominent among them, meaning it is very easy to separate the males from the females. Generally, females are generally smaller than their male counterparts.
Without a doubt, the most prominent feature of their appearance is their claws. While the males have a major and a minor claw, the females, on the other hand, have two minor claws. As the name suggests, the major claw that is seen in males is much larger and is prioritized as a tool.
They walk with their four pairs of legs that are situated behind their claws. Their body is protected by a carapace, i.e. a hard plate which protects their organs.
Speaking of colours, they are not the most colourful of the bunch. You would find most of them being in different shades of orange or brown, though few rare variants have distinct colours. It should be noted that they are known to change their colours in response to changing environmental conditions and for social interactions.
They moult every eight weeks. Moulting is the process of crustaceans leaving their exoskeletons. You would be amazed to know that if they lose their limb, they can automatically develop a new one.
Diet of Fiddler Crab
Fiddler Crabs are detritivores, meaning they sift out dead matter from the substrate to eat. In the wild, they eat anything from fungus to algae. They are omnivores by nature. You can feed them skinning foods such as shrimp pellets as well as frozen shrimps and frozen planktons since they are full of nutrients. However, be sure to defrost the food before putting them into the tank. Also, large pieces of food should be broken down into small fragments.
Feel free to provide them with green vegetation as well. Lettuce, zucchini, and seaweeds are some of the most preferred options. Calcium is also very important for their diet. Each time they moult, they consume parts of their leftover exoskeletons. This is why it is suggested to leave the old exoskeletons in the water for at least a week or so.
Ideally, you should feed them once a week in small portions. This means giving them a few shrimp pellets and a couple of frozen planktons. It would be great if you can switch up their food every now and then, switching between bloodworms and seaweed. A diverse diet will help them grow healthily. When your aquarium develops the smell of ammonia, you need to understand that you are feeding them too much.
An interesting aspect of their eating pattern is that the females are much more efficient at eating since they can use both their claws to feed themselves. This is not the case for the males as their major claw makes it difficult for them to eat.
Behaviour of Fiddler Crab
Fiddler Crabs are semi-terrestrial meaning they can live both on land and being submerged in water. They use their claws to dig burrows, fight and court. They also communicate with one another by raising and lowering their claws.
Generally, they are pretty peaceful and the only time they are aggressive is when males are competing with each other.
Tank Requirements of Fiddler Crab
Provide them with a sandy and soft substrate since they love to sift through it. They need plenty of hiding spaces in the forms of rocks and artificial caves and castles.
Please remember not to fill up the tank to the top with water as air is essential for them. It would be great if you can provide a tall structure that rises above the water level where they could rest to take in some air. However, make sure that the structure doesn’t touch the walls of your tank as they may use it to escape.
Use brackish water with a temperature of 75-86° F (23-30° C), pH level f 8.0-8.3, a salinity of 1.01-1.08 and a hardness of 15 dKH. You need to aerate the tank through a filter or air pump as they need a high level of oxygen.
A 10-gallon tank will suffice for 1-4 Fiddler Crabs. For each additional crab, add 3-5 gallon of space. Breeding them in captivity is extremely difficult so we won’t recommend it. So, you need to buy them from a reputed vendor.