The banded brittle star occurs in the eastern Pacific Ocean, along the coasts of North and Central America from Santa Barbara, California, to Ecuador, as well the Galapagos Islands.

The exact shape and color of the bands can vary depending on the individual; they may appear oval, diamond-shaped, or rectangular, and range in various shades of gray-brown.

variegate, a small commensal polychaete which climbs the arms of the banded brittle star and attaches itself to its host's central disc.

The worm's position on the central disc (whether it is on the aboral or oral side, near the brittle star's mouth) may be determined by the amount of light present in its environment, as observed during research conducted from 2007 to 2013.

During this research, the scale worm was shown to greatly prefer the banded brittle star as a host over other similar species in the same genus.