How big can a brittle star?

Brittle stars, or ophiuroids are echinoderms, closely related to sea stars. The ophiuroids generally have five long slender, whip-like arms which may reach up to 60 centimeters (2 feet) in length on the largest specimens. They are also known as serpent stars. There are some 1,500 species of brittle stars living today, and they are largely found in deep waters more than 500 metres (1,650 feet) down.