Colours
Distinguishing features
Upper disc surface is covered with granules except for the small, dark radial shields which are bare. On the underside, there is a supplementary plate distal to each of the large oral shields. Arm spines are shorter than the dorsal arm plates except for the lowest which is at least as long as the arm plate, and all are erect, standing away from the arm.
Size
- Up to 3 cm (disc diameter)
Depth range
- Depth range data is not yet available.
Synonyms
Distribution
©Atlas of Living Australia: Australian distribution
Local abundance
- Lizard Island: Rarely seen due to cryptic habit but clearly common - many appear out of the reef matrix to spawn.
Behaviour
Numerous individuals observed spawing at 9.30 to 11 pm on 11 Dec 2014 by Lyle Vail and Anne Hoggett. Corals were spawning at the same time. No obvious aggregating behaviour, mostly one individual on a coral head, sometimes two. At least 20 individuals seen in an area of about 250 square metres. Individuals were fully or partly exposed and all exuded substantial quantities of fine "smoky" spawn, apparently sperm, indistinguishable between individuals.
Web resources
References
References that assist with identification
- Clark, A.M. and F.W.E. Rowe (1971). Monograph of shallow-water Indo-west Pacific echinoderms British Museum (Natural History), London.