Common name: anemone spider crab

General information

The Spider Crab, scientifically known as Inachus phalangium, is a species of crab that is well-regarded for its unique appearance and behavior. It is a small crab with a triangular body and long, thin legs that give it a spider-like look, hence the name. This species is often sought after by advanced hobbyists who appreciate its role in the cleanup crew, as it helps to control algae and detritus in the aquarium.

Care

Spider Crabs are generally hardy and can adapt to a range of conditions found in well-established reef aquariums. They require a tank with plenty of live rock and hiding places to feel secure. It's important to ensure that the aquarium does not have aggressive fish that may prey on these small crabs. They feed on algae, detritus, and leftover food, making them beneficial for maintaining tank cleanliness.

Reproduction

In the wild, Inachus phalangium undergoes a complex reproductive cycle that includes a planktonic larval stage. In captivity, breeding is not commonly achieved, and the specifics of their reproductive behavior are not well-documented in home aquariums.

Symbiosis

An interesting aspect of the Spider Crab's biology is its symbiotic relationship with certain anemones. In the wild, it is often found carrying small anemones on its shell, which provide protection through their stinging cells. In return, the crab offers the anemone mobility and access to food particles.

Habitat

Inachus phalangium is native to the Eastern Atlantic, from the British Isles to the Azores and the Mediterranean Sea. It typically inhabits shallow waters, hiding among rocks, sponges, and seagrasses.