Arrow crabs, also known as Yellow line Arrow Crabs, have extremely long spider-like legs with deep violet tips.  Their body is a triangular-shape with an extremely pointed head.  Their body color is a medium golden brown with brown, black, yellow or gold stripes on their dorsal side.  Their eyes protrude on stalks, and they have 10 legs (8 for walking and 2 pincers).

Arrow Crabs average around 2.5 inches in length, and their legs can be more than three times its body length. Males are larger than females.

Arrow crabs can be extremely territorial when threatened. They are nocturnal so they scavenge the reefs for algae, worms (tube, duster and bristle), other invertebrates and dead organisms at night and hide during the day.

They prefer rocky areas and coral reefs where they can hide, but they are also seen in sponges, the spines of urchins and under anemones.