Macrophiothrix propinqua (Lyman, 1861)

Boissin, Emilie, Hoareau, Thierry B., Paulay, Gustav & Bruggemann, J. Henrich, 2016, Shallow-water reef ophiuroids (Echinodermata: Ophiuroidea) of Réunion (Mascarene Islands), with biogeographic considerations, Zootaxa 4098 (2), pp. 273-297 : 281-282

Macrophiothrix propinqua (Lyman, 1861)

(UF-6556, Fig. 3 b, KU594366 )

Material. 1 spm, St. 2; 3 spms, St. 4; 1 spm, St. 7

Remarks. Radial shields about three fifths as long as disc radius, bare. Both disc and arms bright reddish/ orange. Scales on the disc bear small flat white tubercles. There are 8-10 strips of interradial scales and one strip of scales that separates the radial shields. This species fits the former subgenus Keystonea , now synonymized with Macrophiothrix . Abundance: 1.

Distribution. A widespread IWP species ( Clark & Rowe, 1971; Stöhr et al. 2016).

Macrophiothrix robillardi ( DE LORIOL, 1893) (REU-3614, Fig. 3 c)

Material. 2 spms, St. 8

Remarks. These two specimens, contrary to those from the three previous species, do not present trapeziform dorsal arm plates. The disc bears elongate granules dorsally and the radial shields are bare. Some elongated granules are present at the distal edge of the radial shields and form a kind of crown, as also visible in the holotype of M. rugosa (synonymised with M. robillardi ) ( Hoggett 1991). The dorsal arm plates have a characteristic rugose aspect when not wet. The arm spines are not conspicuously thorny as in other Macrophiothrix species. The oral shields do not bear spinelets. The colour is variegated; the disc and the radial shields are blue/grey, with beige/pale yellow granules. The dorsal arm plates are darker (red/brown) every three to four segments. A yellow median line runs along the arms in living animals; Hoggett (1991) reported a white line in preserved specimens. Disc granules are denser in one of the two specimens at hand; a character that often distinguishes species in this genus ( Hoggett 1991). Abundance: 1.

Distribution. Known from Mauritius (type locality; de Loriol, 1893a), Rodrigues ( Rowe & Richmond 2004), Guam ( Starmer 2003), Australia, China and Cook Islands (reviewed in Hoggett 1991). This is the first record for Réunion.

Figures

FIGURE 3. Pictures of species encountered in Réunion Island waters. Pictures were taken of freshly collected specimens except when indicated. Photo credit: BIOTAS.