©Anne Hoggett: A poor photo of a specimen of Astrobrachion adhaerens coiled tightly to a black coral at Pidgin Point, January 2009
Colours
Distinguishing features
A smooth, moderately large brittlestar that is always found coiled tightly around the branches of black corals.
Colour varies from dark burgundy through orange/brown and pale pink to almost white. The disc and basal part of the arms are the same colour. The arms can be a solid colour, or they can become paler towards the arm tip, or there can be a pair of dark midlines. Coleman (2007) shows individuals with a single dark midline but that pattern has not been observed at Lizard Island (yet). Individuals with different colour patterns can inhabit the same black coral.
Size
- Up to 1 cm (estimated disc diameter)
- Up to 20 cm (estimated arm length)
Depth range
- Depth range data is not yet available.
Synonyms
Comments
Only two species of Astrobrachion are currently recognised (WORMS accessed 23 Feb 2019): the temperate Astrobrachion constrictum and the tropical Astrobrachion adhaerens. Lizard Island specimens are identfied here as the tropical species based only on their location. Rowe and Gates (1995) include the Great Barrier Reef within that species' distribution.
The type locality of Astrobrachion adhaerens is near Shark Bay, Western Australia. The specimen illustrated in the original description (Studer, 1884) has six arms. The local specimens have five. There has been little research on this species, taxonomic or otherwise, and it is possible that more species exist.
by Anne Hoggett
Distribution
©Atlas of Living Australia: Australian distribution
Web resources
References
References that assist with identification
- Coleman, N. (2007). Sea Stars: Echinoderms of the Asia/Indo-Pacific Neville Coleman's Underwater Geographic, Springwood, Qld. Australia.
Other references
- Rowe, F.W.E. and J. Gates (1995). Echinodermata in: Zoological Catalogue of Australia. Vol. 33, xiii, 510 pp. Wells, A. (Ed.). CSIRO, Melbourne, Australia.