Red Clawed Crab (Perisesarma bidens)

The Red Clawed Crab is a fascinating semi-aquatic crustacean known for its vibrant coloration, energetic behavior, and unique care needs. Native to the mangrove swamps and estuaries of Southeast Asia, these crabs are often kept by aquarists who enjoy an active and engaging addition to their tanks. Their bright red claws and curious personalities make them stand out in any setup.

Appearance and Behavior
Red Clawed Crabs are easily recognized by their striking red claws, which contrast beautifully against their dark brown or black bodies. Males typically have larger, more colorful claws, while females have smaller ones and a broader abdomen. These crabs can grow up to 4 inches across, including their legs.

They are curious, intelligent, and territorial creatures. You’ll often see them exploring the tank, climbing rocks, or digging in the substrate. However, they can also be aggressive toward other crabs, so space and proper hiding spots are essential.

Habitat and Tank Setup
While often sold as freshwater pets, Red Clawed Crabs actually thrive in **brackish water**—a mix of freshwater and marine salt. A salinity level around 1.005–1.010 specific gravity is ideal. They also need access to both land and water areas since they spend much of their time above the surface.

A good setup should include:

* **Tank Size:** Minimum of 10 gallons for a small group.
* **Substrate:** Sand or fine gravel for digging.
* **Land Area:** Rocks, driftwood, or floating platforms where they can climb out of the water.
* **Water Conditions:** Temperature between 75–82°F and pH around 7.5–8.5.
* **Filtration:** Gentle filtration to maintain clean water without creating strong currents.

Diet
Red Clawed Crabs are **omnivorous scavengers**, meaning they eat a wide variety of foods. In captivity, they can be fed:

* Sinking crab or shrimp pellets
* Blanched vegetables (like zucchini, spinach, or peas)
* Algae wafers
* Occasional treats of bloodworms or brine shrimp

Providing a balanced diet will help maintain their bright coloration and overall health.

Tank Mates
Due to their territorial nature, Red Clawed Crabs are best kept **alone or in small groups** with plenty of space and hiding spots. They may pinch or harass slow-moving fish or shrimp, especially if confined in a small tank. Suitable tank mates include fast-swimming brackish fish like mollies or guppies, but always monitor interactions closely.

Molting and Care
Like all crustaceans, Red Clawed Crabs molt as they grow, shedding their exoskeleton to form a new one. During this time, they are very vulnerable and should be left undisturbed. It’s important to provide hiding areas where they can safely molt and recover.

Breeding
Breeding Red Clawed Crabs in captivity is extremely challenging. Females release larvae into the water, but these larvae require marine conditions to develop, making it difficult to raise them in a standard aquarium.

Conclusion
The Red Clawed Crab is an eye-catching and rewarding pet for aquarists who are willing to provide the proper environment. With their semi-aquatic needs and lively personalities, they add a unique dynamic to brackish aquariums. Observing their natural behaviors—climbing, scavenging, and exploring—makes them a true delight for any aquatic enthusiast.

Perfect for aquarists looking for something different, the Red Clawed Crab brings both color and character to the tank when given the right care and habitat.