"Elbow Crab,", Mesorhoea belli: This species of Elbow Crab, which currently has no known popular name, reaches a maximum size of 1.98 cm (1.5 inches) by 14.9 cm (1.1 inches) with males being larger than females.
Mesorhoea belli are found south of Magdalena Bay on the Pacific Coast of Mexico's Baja California peninsula, throughout the Sea of Cortez, and along the coast of the Mexican mainland south to Guatemala at depths of between 60 and 240 feet in the water column, within mud, sand, rock and shell bottoms.
This crab species is a poorly documented member of the Parthenopidae Family which are the Elbow Crabs.
They have pentagonal shaped bodies and are normally colored to blend into their substrate within which they live. They have small eyes and are characterized by a pair of highly disproportionately elongated chelipeds (entire claws) that stick out from the sides of the body.
The claws have an upper movable finger (dactyl) that is curved inwards toward the immovable lower finger and the inner surfaces have rows of colored bumps and spots that are believed to be used to startle prey.
Males have larger claws (chela) than females. The walking legs are thin and small and have pointed tips. They are slow moving and consume worms and small snails and clams.