species: Macrophiothrix propinqua in Lizard Island Field Guide (Lizard Island Field Guide)
Macrophiothrix propinqua

©Anne Hoggett: Macrophiothrix propinqua found under a slab of rubble on the reef flat at south end of Hicks reef, February 2009. Disc diameter is about 11 mm, arms about 7 cm long.

©Anne Hoggett: Fan-shaped dorsal arm plates of Macrophiothrix propinqua, some even appearing trilobed. Same specimen as photographed above.

©Anne Hoggett: Bare radial shields, contrasting with thorny disc armament. Same specimen as photographed above.
Kingdom Animalia
Phylum Echinodermata
Class Ophiuroidea
Order Ophiurida
Family Ophiotrichidae
Genus Macrophiothrix
Species Macrophiothrix propinqua



Distinguishing features

Macrophiothrix species are difficult to distinguish in the field because microscopic examination of characters is necessary. Most species in the genus are large (disc diameter can be more than 20 mm), have very long arms, and live on soft sediment under slabs of rubble.

Macrophiothrix propinqua is one of the smaller species of the genus with maximum known disc diameter only 11 mm. It also has has relatively short arms, 6 to 14 times the disc diameter. The specimen from Hicks Reef photographed above is a large one for this species, with disc diameter about 11 mm and arms six to seven times that length. Radial shields (five pairs of conspicuous triangular disc plates) are bare. The rest of the disc surface can also be bare or it can be armed with low, rough granules as in the Hicks Reef specimen. Dorsal arm plates are wide and fan-shaped with a tendency for the distal edge to have three lobes. The arms are banded brown and red and there is also usually a paler or darker longitudinal midline.


  • Size data has not been obtained.

Depth range

  • Depth range data is not yet available.



©Atlas of Living Australia: Australian distribution

Web resources


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.
  • Hoggett, A.K. (1991). The genus Macrophiothrix (Ophiuroidea: Ophiotrichidae) in Australian waters, Invertebrate Taxonomy, 4: 1077-1146. LIRS catalog number 293.

Other references

  • Hoggett, A.K. (1990). Taxonomy and systematic position of the brittlestar genus Macrophiothrix H.L. Clark (Echinodermata: Ophiuroidea), Ph.D. thesis, University of Queensland. LIRS catalog number 680.
  • View all references