graphic range. Brittle stars can be found at various depths of the ocean and tend to cling to rocks for concealment. They cannot be found on land or fresh water. These organisms are not often seen because they live under rocks or in coral, seaweed and they burrow into the mud or sand.3.1 AggregationThese marine organisms tend to aggregate in large numbers and evidently also did so in the past. Fossil beds consisting almost exclusively of large numbers of one or a few species are known from as early as the Lower Cambrian. In present day these species including most echinoderms may cover large areas of the seafloor. The reason behind aggregation apparently is a response to one or more environmental factors, primarily food. Large numbers of ophiuroids including brittle star and crinoids occupy areas in which strong currents carry large amounts of plankton. A brittle starfish raises some of his arms in the water to capture the plankton and using the existing arms to hold on to other brittle stars. They do this so that they will not be swept away by the current.4.0 Food ProcurementBrittle starfish obtain food by using its long arms to bring food to its mouth; the tube feet bring small particles of food to its mouth.4.1 Place in the Food ChainSome brittle starfish are scavengers, eating plant or animal material that they come across. Many of these species develop relationships with sponges or corals. They clean the host of debris and in return get a safe place to live. Some brittle starfish are predators as they catch shrimp, as they get older they catch bigger organisms such as squid and fish.4.1 Food SourceBrittle stars eat many things. A brittle star's diet can include barnacles, snails, sea urchins, clams and mussels. They also eat small animals and plankton. Many brittle stars eat mussels and clams. They also feed on detritus and small living or dead animals. After they get big enough they will in fact catch and eat fish hermits and con...
