GENERAL HISTOLOGY

Detailed explanation-1: -Brittle stars, most of which have five flexible arms, occasionally lose some of them and promptly coordinate the remaining arms to escape from predators.

Detailed explanation-2: -Each brittle star has a distinct central disk and five skinny, flexible arms. The central disk is made up of a skeleton of calcium carbonate and contains all the internal organs. Brittle stars’ arms twist and coil to help them move across the seafloor.

Detailed explanation-3: -Brittle stars move fairly rapidly by wriggling their arms which are highly flexible and enable the animals to make either snake-like or rowing movements. However, they tend to attach themselves to the sea floor or to sponges or cnidarians, such as coral.

Detailed explanation-4: -Instead of crawling on hundreds of tube feet like starfish, brittle stars move fairly rapidly by wriggling their arms. These agile arms are supported by an internal skeleton of calcium carbonate plates that superficially look like vertebrae, and that are in fact called vertebral ossicles.

Detailed explanation-5: -All the brittle star species found in Puget Sound have five arms but species in other areas sport up to nine. They use their arms and tubed feet with suckers at the ends to get around.