Common name: Pom-pom Crab

General Information

The Pom-pom Crab, scientifically known as Lybia tessellata, is a fascinating and unique addition to marine aquariums. This small crustacean is named for its distinctive behavior of carrying sea anemones in its claws, resembling pom-poms. These anemones are not just for show; they serve as both a defense mechanism and a tool for gathering food. The Pom-pom Crab is a favorite among hobbyists for its quirky appearance and intriguing symbiotic relationship with its anemones.

Native to the Indo-Pacific region, Lybia tessellata is typically found in coral reefs and rocky substrates, where it hides during the day and becomes more active at night. Its small size and peaceful nature make it an excellent choice for nano and reef aquariums, provided its specific needs are met.

Physically, the Pom-pom Crab is characterized by its mottled brown to red and white carapace, which provides excellent camouflage in its natural habitat. Its most striking feature, of course, is the pair of small sea anemones it carries in its claws. These anemones are not naturally attached to the crab but are carefully held and even split into smaller pieces if one is lost, showcasing the crab's resourcefulness.

Care

The Pom-pom Crab is relatively easy to care for, making it suitable for aquarists with some experience. It thrives in well-established reef tanks with plenty of live rock and hiding spots. These crabs are nocturnal and prefer dim lighting or shaded areas during the day. They are reef-safe and will not harm corals or other invertebrates, but care should be taken to ensure they are not housed with aggressive tank mates that might prey on them.

A stable environment with consistent water parameters is crucial for the health of Lybia tessellata. Regular water changes and proper filtration will help maintain the pristine conditions this species requires. While they are peaceful, they should not be housed with large or predatory fish that may see them as a snack.

Diet and Feeding

In the wild, Pom-pom Crabs are opportunistic feeders, using their anemones to capture small particles of food, plankton, and detritus. In captivity, they can be fed a varied diet that includes finely chopped seafood, frozen mysis shrimp, and high-quality pellets or flakes. Target feeding near their hiding spots can ensure they receive adequate nutrition, as they may be outcompeted by more active tank mates during feeding times.

Feeding once a day is generally sufficient, but care should be taken not to overfeed, as uneaten food can degrade water quality. Observing their feeding behavior can also be a delightful experience, as they wave their anemones to capture food particles in the water column.

Behavior and Compatibility

The Pom-pom Crab is a peaceful and shy species, often spending its days hidden among rocks or in crevices. It is most active at night, when it ventures out to forage for food. Its unique behavior of carrying anemones makes it a fascinating addition to any reef tank, and it is sure to be a conversation starter among fellow hobbyists.

While generally peaceful, Lybia tessellata may exhibit territorial behavior towards other crabs or similar species, especially in smaller tanks. Providing ample hiding spots and space can help minimize any potential conflicts. They are best kept singly or in pairs in larger tanks to avoid competition.

The Pom-pom Crab is reef-safe and can coexist with a variety of tank mates, including small, non-aggressive fish and other invertebrates. However, avoid housing them with predatory species that may view them as prey.

Symbiosis

One of the most remarkable aspects of Lybia tessellata is its symbiotic relationship with sea anemones, typically from the genus Triactis. The crab uses these anemones for both defense and feeding, waving them to deter potential predators and to capture food particles. In return, the anemones benefit from increased mobility and access to food.

If the crab loses one or both of its anemones, it has been observed to "steal" anemones from other crabs or even split its remaining anemone into two, ensuring it always has a pair. This behavior highlights the importance of the symbiotic relationship to the crab's survival.

In captivity, the anemones carried by the Pom-pom Crab may not always thrive, but the crab can adapt by using other soft corals or similar substitutes. Observing this symbiotic relationship in a home aquarium is both educational and entertaining.

Health and Common Issues

The Pom-pom Crab is a hardy species when kept in optimal conditions. Its small size and peaceful nature make it less prone to stress, provided it is housed in a stable and well-maintained environment. Regular monitoring of water parameters and avoiding overcrowding are key to its health.

When selecting a Pom-pom Crab, look for individuals with intact limbs and active behavior. Missing anemones are not a cause for concern, as the crab can replace them over time. Avoid crabs that appear lethargic or have visible signs of disease.

Common health issues include stress from aggressive tank mates and poor water quality. Ensuring a peaceful environment and maintaining pristine water conditions can help prevent these problems. If the crab appears inactive or stops feeding, check for potential stressors or changes in water parameters.