Ophiomoeris cf. obstricta ( Lyman, 1878 )

Stöhr, Sabine, 2011, New records and new species of Ophiuroidea (Echinodermata) from Lifou, Loyalty Islands, New Caledonia, Zootaxa 3089, pp. 1-50 : 23-24

Ophiomoeris cf. obstricta ( Lyman, 1878)

Figure 8 C–E

Material. Sta. CP1646: 2 spms, 5.3 and 3.3 mm dd.

Description. Radial shields almost oval, separated over their entire length by small, tumid scales in the larger specimen, diverging distally and there separated by a triangular plate (dorsal arm plate) about twice as wide as long. Central dorsal disk plate knob-like, encircled by round, likewise knob-like, tumid scales of different sizes. No granules. In the smaller specimen all scales flat, suggesting ontogenetic differences. Interradially small flat scales embedded in skin. Larger specimen with six arm spines proximally, reducing in number distalwards. Dorsalmost spine longest, longer than an arm segment, and spines decrease in size ventralwards. Jaws with a large pointed apical papilla, two pointed lateral papillae proximally and a scale-like distal one. Adoral shields large, curved and not reaching around the small fan-shaped oral shield. Ventral arm plates short, at least twice as wide as long proximally. All plates have a glassy bead-like stereom.

Remarks. Ophiomoeris currently contains four species, O. nodosa ( Koehler, 1905) , O. obstricta , O. exuta sp. nov. and O. tenera , but the status of the last species is still unclear ( O’Hara & Stöhr 2006). The Lifou specimens fall within the variability of O. obstricta documented by O'Hara & Stöhr (2006), but further study will have to show whether O. obstricta is a morphologically highly variable species with a wide geographic distribution or a complex of several genetic lineages.

Distribution. Widely distributed across the Indo-Pacific Ocean.

Figures

FIGURE 8. A, B, Ophiomoeris exuta sp. nov., holotype MNHN IE- 2009 - 9207, prior to SEM preparation; A, dorsal aspect; B, oral frame and ventral arm. C – E, Ophiomoeris cf. obstricta; C, dorsal aspect; D, jaw details; E, dorsal arm. F, Ophiomitrella granulosa, spotted form, dorsal aspect. Scale bars 1 mm.