Have you ever wondered what’s in the ocean underneath rocks and coral? Well, brittle stars are probably one of those things that you didn’t know about.

           

A brittle star is similar to a starfish, but its five arms are not connected to each other. They are about the size of an outstretched human hand and have whip-like arms that can grow up to two feet long. Brittle stars can grow back-lost arms. Brittle stars have a small disk shaped body and on their underside they have a sack- like stomach. They prefer the dark so they live under rocks or cracks in coral, or burrow in mud or sand. Brittle stars are a dark reddish color during the day and turn to a blackish brown and grey color at night; some brittle stars match the color of their surroundings.

           

When a brittle star is hiding in coral they have a photoreceptive system. Their photoreceptive system functions like an eye allowing brittle stars to detect predators and seek safety. Brittle stars are found in coral reefs from Bermuda to Brazil. They live beneath the reef coral and rubble. There are approximately 2,000 species. Their population is dense in certain areas.

           

Brittle stars eat between dusk and dawn. Brittle stars are suspension feeders, which means that they eat water particles that are suspended in the water column. Brittle stars have an incomplete digestive system, which means that their digestive tract is their mouth and anus. Fish are the main predators of brittle stars. Some brittle stars that suspension feed are nocturnal. Few brittle stars may be bioluminescent which scare predators away by the light that they produce when disturbed.

           

Now that you have learned a few things about brittle stars I hope you become more interested in marine life you may not have known existed.      

 

Author: Sylinda V

Published: 2/19/13       

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Sources: Wikipedia.com

                Madsci.org

                Reef.edu.au

                News.nationalgeographic.com

                Biogeodb.stri.si.edu