Libinia dubia belongs to a group of brachyuran crabs commonly referred to as decorator crabs. Using hooked, Velcro-like setae on the surface of the carapace, the crabs attach bits of algae and invertebrates for camouflage. This behavior is most common in juveniles, and the shells of adult crabs are usually found clean. Under the decorative covering, the carapace of L. dubia is rounded, bearing approximately six spines down either side and along the median line on the dorsal surface (eg. Corrington 1927). A forked rostrum extends between the eyes, and the overall color of the body is yellowish to brown (Voss 1980). Long, thin walking legs originating from the rounded body give the crab the spidery appearance for which it is named. These legs culminate in curved points, allowing the crab to cling to various surfaces like rocks and jellyfishes (Ruppert & Fox 1988).