Appearance
Loxechinus albus is a fast-growing, relatively large sea urchin with a test diameter of up to 11 cm (4.3 in), although the far southernmost populations tend to grow slower and reach a smaller size. The test is dorsoventrally flattened and densely covered in small spines. Living individuals of this urchin typically appear overall dull reddish with some pale green to the spines, but its color is variable, and some large specimens have been found in deeper waters which are white. There are 6 to 11 ambulacral plates each bearing a single short primary spine and many longer secondaries. The globiferous pedicellariae have a neck between the stem and head, large valves and several lateral teeth.

