Trapezia rufopunctata

Appearance

''Trapezia rufopunctata'', also known as the commensal crab, can reach the size of about 5 cm in width. They are considered true crabs, with 4 walking legs and a pair of proportionally large and long, flattened clawed legs . The trapezoidal carapace has a unique mottled pattern, with around 100 to 200 reddish or orange spots on a white or pink background, earning it the common name of the “rust spotted guard crab”. Their appearance is believed to help it camouflage within the colorful corals in which it resides. Its eyes, however, are a contrasting shade of green. ''Trapezia rufopunctata'' use drag powered swimming to move around. This guard crab, similar to other members of the family, lives symbiotically in association with corals. Behaviorally, this species avoids confrontation, quickly retreating into coral branches when approached while holding its claws up defensively. These crabs are gonochoric and their mating behavior includes a precopulatory courting ritual which is often instigated through olfactory or tactile cues. They reproduce sexually and the resulting fertilized eggs are carried by the female, and the mating pair often occupy the same coral colony together afterwards. The eggs hatch into planktonic larvae before growing into the distinctive aforementioned adult characteristics.

Distribution

This species is widespread in the Indo-Pacific, Maldives and Polynesia. It has specifically been widely seen and photographed near the Great Barrier Reef in Australia and Bali, Indonesia. They have been found as far west as Hawaii, as east as eastern Africa, as north as southern Japan, and as south as South Africa. ''Trapezia rufopunctata'' inhabits coastal reefs and lagoons, mostly due to their symbiotic relationship with corals. Typically, that is shallow water at a depth of 0-30 meters with sea surface temperatures ranging from 68-97 degrees Fahrenheit.

Habitat

This species is widespread in the Indo-Pacific, Maldives and Polynesia. It has specifically been widely seen and photographed near the Great Barrier Reef in Australia and Bali, Indonesia. They have been found as far west as Hawaii, as east as eastern Africa, as north as southern Japan, and as south as South Africa. ''Trapezia rufopunctata'' inhabits coastal reefs and lagoons, mostly due to their symbiotic relationship with corals. Typically, that is shallow water at a depth of 0-30 meters with sea surface temperatures ranging from 68-97 degrees Fahrenheit.