Red Claw Crab: Care & Tank Setup Full Guide

Are you a fan of unique aquatic pets? If so, Red Claw Crabs, with their vibrant appearance and quirky behaviors, might be just the species you’re looking for. These intriguing crustaceans add a whole new level of charm to your aquatic setup.

However, providing a comfortable home for these fascinating creatures isn’t a matter of guesswork. Understanding their needs for a specific tank setup, diet, and care regimen is paramount. This knowledge will ensure your Red Claw Crab not only survives, but thrives, adding color and life to your aquatic world.

General Information About Species

The Red Claw Crab, scientifically known as Perisesarma bidens, is a small, vibrant crustacean native to the brackish coastal areas of Asia. Noted for their striking red claws and intricate patterns, they are a popular choice among aquarium enthusiasts.

Despite their petite size, Red Claw Crabs are quite territorial, demanding ample space in their habitat for burrowing and exploration. They are semi-aquatic species, needing a habitat that includes both water and dry land areas.

As omnivores, these crabs have a varied diet, feeding on plant matter, detritus, and occasionally, small invertebrates. With a lifespan of up to three years in captivity, their care necessitates an understanding of their unique lifestyle and environmental needs.


Red Claw Crabs are quite distinctive in their appearance, making them a visually appealing choice for many aquarium enthusiasts. They are generally small, reaching only about 2 to 2.5 inches (5-6 cm) in width across their carapace or body, with males typically being slightly larger than females.

Their coloration varies from dark brown to a lighter, sandy color, often mottled or speckled. They are most recognized for their bright red claws, hence the common name, which is especially vivid in males. However, females also have red claws, but they are usually smaller and not as brightly colored.

They have a somewhat flat, square-shaped body with long, agile legs, and their eyes are situated on stalks that extend from the front of their body. This unique eye placement allows them a broader field of vision in all directions. In addition to their main claws, they also have smaller appendages near their mouth area, known as maxillipeds, used for feeding and grooming.

Their overall unique appearance combined with their engaging behaviors make them a captivating addition to suitable aquatic habitats.


The lifespan of a Red Claw Crab can vary depending on whether it lives in the wild or in captivity, as well as on factors such as diet, habitat, and overall health.

In the wild, Red Claw Crabs have been known to live for up to 3 years. However, due to threats such as predators, disease, and harsh environmental conditions, some crabs may not reach this age.

In captivity, with a well-maintained environment, a balanced diet, and without the threat of predators, Red Claw Crabs also typically live up to 3 years. However, instances of longer lifespans have been reported when the crabs are given exceptional care. It’s worth noting that a crab’s lifespan in captivity is heavily dependent on the quality of care and the conditions in which it is kept. Appropriate tank setup, temperature regulation, salinity control, and proper feeding are all critical elements in ensuring your Red Claw Crab lives a full and healthy life.


Red Claw Crabs are relatively small in size, which makes them suitable for home aquariums. On average, they reach a width of about 2 to 2.5 inches (5-6 cm) across their carapace, or body, once they’re fully grown. This size does not include their legs or claws, which can extend their overall appearance somewhat.

It’s worth noting that there can be a slight size difference between males and females of the species. Males tend to be a bit larger than females overall, and also possess larger, more brightly colored claws – a characteristic trait for which these crabs are named.

Tank Water

Creating an optimal environment for your Red Claw Crabs is paramount to their well-being. Here are the primary water requirements for their tanks:

  1. Type of Water: Red Claw Crabs are brackish water creatures. This means the tank water should be a mix of freshwater and saltwater. This can be achieved by adding marine aquarium salt to your tank. Always consult product instructions or a pet care expert to ensure the correct amount.
  2. Specific Gravity: The specific gravity of the water, a measure of its salinity, should ideally be between 1.005 and 1.010. Use a hydrometer to measure this accurately.
  3. Temperature: The water temperature should be maintained between 75-85°F (24-29°C). A reliable aquarium heater and thermometer can help regulate this.
  4. pH Levels: The pH level of the water should be kept between 7.5 and 8.5 to mimic their natural habitat. Aquarium pH test kits can be used to monitor this.
  5. Water Filtration: A high-quality filter is needed to remove harmful chemicals and waste from the water, helping to maintain its cleanliness.
  6. Water Change: Regular water changes are crucial. Typically, 25% of the water should be replaced with fresh, appropriately treated water every two to four weeks, depending on the tank size and cleanliness.
  7. Tank Layout: As semi-aquatic creatures, Red Claw Crabs require a tank setup that includes both land and water areas. Ensure there is enough land area for the crabs to get out of the water completely, as well as deep enough water sections for them to fully submerge.

Remember, each Red Claw Crab is unique and might require slight adjustments to these general guidelines. It’s best to monitor your crabs closely and make any necessary changes to ensure their health and longevity.

Tank Size

Red Claw Crabs, though small, demand ample space due to their territorial nature. A 10-gallon tank is generally the minimum recommended size for a single crab, ensuring it has sufficient room to explore and burrow.

If you’re planning on multiple crabs, add an additional 10 gallons per crab. This ensures enough space for each to establish its own territory, reducing the risk of stressful conflicts.

Remember, your tank needs to accommodate both land and water areas for these semi-aquatic creatures. Larger tanks provide greater flexibility for creating a varied and engaging habitat.

Tank Setup

Creating an ideal habitat for Red Claw Crabs involves more than just the right size tank and water conditions. Here are some key components to consider when setting up their tank:

  1. Land and Water Areas: Red Claw Crabs are semi-aquatic and require a habitat that includes both land and water areas. Ideally, the tank should be half water and half land. The water section needs to be deep enough for them to fully submerge, while the land area must be dry and easily accessible.
  2. Substrate: The bottom of the tank should be lined with a substrate that the crabs can burrow in. Sand or fine gravel works well for this.
  3. Decorations: Crabs love to explore and hide. Include rocks, driftwood, and caves for them to climb and hide in. Aquarium-safe plants can also add aesthetic value and provide additional hiding spots.
  4. Filtration: A good filtration system is needed to keep the water clean and free from harmful chemicals and waste.
  5. Heating and Lighting: The water temperature should be maintained between 75-85°F (24-29°C). Aquarium heaters are usually needed to achieve this. Also, while they do not specifically require lighting, a regular day-night light cycle can help mimic their natural environment.
  6. Tank Lid: Red Claw Crabs are excellent climbers and have been known to escape from tanks. A secure lid is essential to keep your crabs safe and contained.

By incorporating these elements into your tank setup, you can create a suitable habitat that closely mimics their natural environment, helping to keep your Red Claw Crabs healthy and happy.

Red Claw Crab Diet

Red Claw Crabs are omnivores, which means they consume a varied diet that includes both plant and animal matter.

In the wild, their diet consists of small invertebrates, detritus (dead plant and animal matter), and various forms of aquatic vegetation. They are known to eat pretty much anything they come across and can handle.

In captivity, this diet can be replicated by providing them with a combination of commercial foods and fresh vegetables. A high-quality sinking pellet or crab-specific food can form the base of their diet. These usually contain a balanced blend of nutrients essential for their health.

In addition to commercial food, fresh or blanched vegetables such as peas, spinach, or zucchini can be offered. Small portions of protein sources like bloodworms, brine shrimp, or bits of fish can also be included occasionally. Providing a mix of these food types ensures they get a balanced diet.

It’s important to remember not to overfeed your crabs. A good general rule is to feed them only what they can consume within a few minutes, once or twice a day. Any uneaten food should be removed from the tank after a while to maintain water quality.

Observing your crabs’ feeding habits and adjusting the quantity and frequency of feeding as needed will help keep them healthy and happy.

Red Claw Crab Behaviour

Red Claw Crabs are known for their unique behaviors that add to their appeal as aquarium pets. They are typically active and observant creatures, often seen climbing or burrowing in their environments, making them an engaging spectacle for their owners.

These crabs are also characterized by their territorial tendencies. Both males and females establish and defend their territories, especially during breeding periods. It’s not uncommon to observe confrontations or claw-waving displays when a territory is threatened.

Despite their semi-aquatic nature, they spend a significant portion of their time on land. Interestingly, they are not excellent swimmers, preferring to walk along the bottom rather than swim freely. This affinity for land, combined with their curious and active nature, necessitates an appropriately designed tank environment with both aquatic and terrestrial areas for exploration.

Mating & Breeding

Breeding Red Claw Crabs in captivity can be a challenging process, as it requires specific conditions and care.

The first step is to ensure you have both male and female crabs. Males can be distinguished by their larger and brighter claws, while females have smaller claws and a broader abdomen. When the female is ready to mate, her abdomen will display a sponge-like structure filled with eggs.

Once the crabs mate, the female carries the eggs in her abdominal area until they hatch. This period usually lasts about a month. During this time, it’s crucial to provide optimal conditions with proper food and low-stress environment to increase the chances of successful hatching.

However, the real challenge comes after the eggs hatch. The newly hatched crabs, known as zoeae, are fully aquatic and require saltwater conditions to survive. They also need a diet of fine particulate food, such as infusoria or newly hatched brine shrimp. After several molts, the zoeae will start to transition into a semi-aquatic lifestyle, similar to adult Red Claw Crabs.


Understanding and meeting the specific requirements of Red Claw Crabs is vital to ensuring their health and longevity in captivity. Their striking appearance and engaging behaviors truly make them unique additions to your aquatic setup, provided their needs for a semi-aquatic, brackish water environment are met.

With the right tank conditions, a balanced diet, and careful attention to their territorial tendencies, these captivating crustaceans can thrive. Remember, the reward of observing these fascinating creatures in a well-maintained habitat offers a rich, immersive experience into the intricate world of crab care.

About The Author

Ellie McDaniel is an experienced aquarium pet owner, whose expertise infuses her informative articles. She shares her deep understanding of aquatic pets, their care, and maintenance through engaging and insightful writings.

Ellie’s knowledge and passion for aquarium pets shine through her articles, providing an invaluable guide for fellow enthusiasts. Her practical experience resonates with readers, making her a trusted resource in the diverse world of aquarium pet care.