Ophiostriatus sexradiatus Irimura, 1993

Okanishi, Masanori & Fujita, Yoshihisa, 2019, A comprehensive taxonomic list of brittle stars (Echinodermata: Ophiuroidea) from submarine caves of the Ryukyu Islands, southwestern Japan, with a description of a rare species, Dougaloplus echinatus (Amphiuridae), Zootaxa 4571 (1), pp. 73-98 : 87

Ophiostriatus sexradiatus Irimura, 1993

[Japanese name: Mutsuude-suji-kumohitode]

( Fig. 9C )

Ophiostriatus sexradiatus Irimura 1993: 161 –164, figs 1, 2.—Y. Fujita et al. 2015: 7, 98, fig.

Material examined. Okinawa Island (RUMF-ZE-02065[1], RUMF-ZE-02066[2], RUMF-ZE-02082[1]): “entrance” of the “Hedo-Dome” cave, under rocks or coral rubble, approximately 15 m depth, 22 May 2017. Ie Island (RUMF-ZE-02067[1]): “entrance” of the “Unnamed cave”, under coral rubble, approximately 18 m depth, 24 June 2017 .

Distribution. Ryukyu Islands, southern Japan. Depth range 18– 40 m.

Remarks. This species is identified as Ophiostriatus sexradiatus by virtue of having: six arms; disc densely covered small granules, aborally and a part of oral plates and adoral shields; four to five arm spines, slender and as long as the corresponding arm segment; two tentacle scales; striated lateral arm plates ( Irimura, 1993).

Figures

FIGURE 9. Aboral views of living specimens. A, Ophiolepis superba H. L. Clark, 1915 (RUMF-ZE-02063); B, Ophiozonella cavernalis Okanishi & Fujita, 2018a (RUMF-ZE-02064); C, Ophiostriatus sexradiatus irimura, 1993 (RUMF-ZE-02067); D, Ophiocoma pusilla (Brock, 1888) (RUMF-ZE-02083); E, Cryptopelta cf. callista H. L. Clark, 1938 (RUMF-ZE-02068); F, Ophiarachnella gorgonia Müller & Troschel, 1842 (RUMF-ZE-02073); G, Ophiopsammus anchista (H. L. Clark, 1911) (RUMF-ZE-02079); H, Ophiarachna mauritiensis de Loriol, 1893a (RUMF-ZE-02070).