Brittle Stars

I never saw a brittle star until I started night diving. Only once I learn to relax on a night dive and move around slowly did I start to notice these weird looking starfish things running for cover whenever I shone my torch under a ledge. I later found out these creatures although related, were not starfish but Brittle Stars.

Brittle stars are in the phylum echinodermata and in the same class (Ophiuroidea) of the Basket Star, .

Appearance
Brittle stars have a central disc like body with 5 arms coming out of the disc. They only come out at night to scurry across the ocean floor looking for food. You are sure to see some on a night dive at Oak Park. Shine your torch up under the ledgers and you will see them scurrying across the bottom out of the light.

Food
A brittle star feeds on plankton, suspended detritus, coral-shed mucus (hmmm yummy) bottom detritus, molluscs and worms. They also scavenge on the bottom for other scraps.

Sex Life
According to Neville Coleman�s Book Sea stars of Australia most Brittle Stars release sperm and eggs into the water and hope for the best, with fertilisation taking place outside the body. Some species are known to actually brood young within the body, some to lay eggs and some to reproduce asexually by self-division. Therefore one brittle star may break into two halves and each half will grow a new half to make them whole again. Thus creating 2 new brittle starts! Brittle Stars have the power to regenerate a missing limb, so if attacked they will readily sacrifice an arm to a predator as they can always grow a new one!

There are many different types of brittle starts and it is quite hard to try and identify them by looking at photos in books. If anyone knows the names of some of the local species please feel free to send me an e-mail and advise me.

References and more information: -
Sea stars of Australia and their relatives, by Neville Coleman, published 1994 By Neville Coleman�s Underwater Geographic Pty Ltd

Australian Marine Life � The plants and animals of temperate waters, Graham J. Edgar, 1997, Reed Books