Red Clawed Crab: A Brackish Beauty Full of Personality
Perisesarma bidens

If you're looking to add something truly unique and interactive to your aquarium setup, the Red Clawed Crab is a captivating choice. With its bold red claws, inquisitive nature, and semi-aquatic lifestyle, this crustacean brings a new level of excitement to paludariums and brackish tanks.

A Striking Appearance

The Red Clawed Crab sports a dark brown to olive body with eye-catching bright red claws, making it one of the most visually striking invertebrates in the hobby. Males typically have larger, more vibrant claws, while females have more rounded abdomens. These crabs are relatively small but full of character.

Natural Habitat & Behavior

Native to mangroves and estuaries across Southeast Asia, Red Clawed Crabs are accustomed to brackish, coastal environments. They are semi-aquatic, spending time both in and out of water, and will explore every inch of their tank with impressive agility—often climbing, burrowing, and rearranging substrate.

Red Clawed Crabs are:

• Territorial and solitary—especially males

• Mostly nocturnal, but may be active during the day

• Excellent escape artists, so secure lids are a must!

Ideal Tank Setup

To keep a Red Clawed Crab happy and healthy, a brackish paludarium setup is ideal. These crabs cannot live fully submerged and need both aquatic and dry land areas.

Setup Recommendations:

• Tank Size: 10 gallons minimum (per crab)

• Water Type: Brackish (SG 1.005–1.010 using marine salt)

• Temperature: 75–82°F (24–28°C)

• pH: 7.5–8.5

• Land Area: At least 50% of the tank should be dry with access to hiding spots

• Décor: Rocks, driftwood, caves, and platforms to climb

• Substrate: Sand or mud for burrowing

• Lid: Secure and tight-fitting to prevent escapes

Proper land and water balance is critical—they must have access to dry areas to molt and rest.

Diet & Feeding

Red Clawed Crabs are omnivorous scavengers, making them easy to feed.

They enjoy:

• Sinking pellets and algae wafers

• Blanched veggies (zucchini, spinach)

• Fish flakes or shrimp pellets

• Occasional protein (bloodworms, brine shrimp, or even small insects)

Feed sparingly to avoid water quality issues, and always remove uneaten food.

Compatibility

While intriguing, Red Clawed Crabs are not ideal for peaceful community tanks. They may pinch slow-moving fish or nip at tank mates if space is limited. Best tank mates include:

• Fast-swimming fish that tolerate brackish water (e.g., mollies)

• Other Red Clawed Crabs in large, well-decorated tanks (be cautious of territorial fights)

• Mudskippers or archerfish in larger setups

Avoid housing them with bottom-dwellers or small shrimp.

Molting & Care Notes

Like all crustaceans, Red Clawed Crabs molt as they grow. During this time, they become vulnerable and often hide. Ensure your tank provides:

• Hiding places (caves, dense plants, or rock crevices)

• Access to both dry land and brackish water

• Stable salinity and clean water to prevent stress and health issues

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Final Thoughts

The Red Clawed Crab is a fun, interactive invertebrate with loads of personality and a splash of color. Best suited for dedicated brackish setups or paludariums, these crabs reward attentive care with fascinating behaviors and bold presence. Whether they’re scavenging for food or showing off those bright red claws, they’re sure to be a conversation piece in any tank.