Common Decorator Crab (Schizophrys aspera) – Complete Care Guide

General Information

The Common Decorator Crab (Schizophrys aspera) is a fascinating species known for its unique habit of adorning itself with pieces of its environment. This behavior not only provides camouflage but also adds a touch of creativity to the crab's appearance, making it a favorite among marine enthusiasts. Found in tropical and subtropical waters, this crab is a master of disguise, blending seamlessly into its surroundings by attaching algae, sponges, and even small invertebrates to its exoskeleton.

Common Decorator Crabs are part of the Majidae family, commonly referred to as "spider crabs" due to their long, spindly legs. Their ability to "decorate" themselves is not just for show; it serves as a critical survival strategy in the wild, helping them avoid predators. This species is relatively small, making it a manageable addition to many marine aquariums.

Care

Common Decorator Crabs are relatively hardy and adaptable, making them suitable for intermediate aquarists. They thrive in tanks with plenty of live rock and a variety of textures and materials they can use for decoration. These crabs are nocturnal and prefer dimly lit environments, so providing shaded areas or caves can help them feel secure.

While they are generally reef-safe, caution is advised as they may occasionally pick at soft corals or polyps to use as decoration. Ensuring they have access to alternative materials like macroalgae or sponge fragments can help mitigate this behavior.

Diet and Feeding

In the wild, Common Decorator Crabs are omnivorous scavengers, feeding on detritus, algae, and small invertebrates. In captivity, they should be offered a varied diet that includes algae wafers, meaty foods like mysis shrimp, and even small pieces of fish or shrimp. Supplementing their diet with dried seaweed or macroalgae can also help meet their nutritional needs.

Feed them every other day, ensuring they have enough food to scavenge without overloading the tank with waste. Their scavenging behavior makes them excellent members of a clean-up crew, helping to keep the tank free of detritus and uneaten food.

Behavior and Compatibility

Common Decorator Crabs are generally peaceful but can be opportunistic. They are best kept with other non-aggressive tank mates and should not be housed with small, slow-moving fish or invertebrates that they might see as potential decoration or prey. They are solitary creatures and do not require companions of their own species.

Their decorating behavior is one of their most endearing traits, but it can also lead to some challenges in reef tanks. They may occasionally "borrow" pieces of coral or other decorative elements, so monitoring their activity is essential.

Symbiosis

While not involved in a specific symbiotic relationship, the Common Decorator Crab's habit of attaching living organisms like sponges or algae to its shell can create a micro-ecosystem. This behavior benefits both the crab and the attached organisms, as the crab gains camouflage while the organisms are transported to new areas with better access to nutrients.

Health and Common Issues

Common Decorator Crabs are hardy but can be sensitive to poor water quality. Maintaining stable water parameters and providing a varied diet are key to their health. They are also prone to losing their decorations during molting, which is a natural process. After molting, they will quickly begin redecorating themselves.

When selecting a Common Decorator Crab, look for active individuals with intact legs and claws. Avoid crabs that appear lethargic or have visible signs of damage or disease.

Habitat

Native to the Indo-Pacific region, Common Decorator Crabs are typically found in coral reefs and rocky substrates. They prefer areas with plenty of hiding spots and materials for decoration. In the aquarium, replicating this environment with live rock, coral rubble, and macroalgae will help them feel at home.

Common name: Common Decorator Crab