Cryptopelta cf. callista H. L. Clark, 1938

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 : 88

Cryptopelta cf. callista H. L. Clark, 1938

( Fig. 9E )

Cryptopelta callista H. L. Clark 1938: 354 , 355, pl. 14, fig. 2; 1946: 264.— A. M. Clark & Rowe 1971: 88, 89, figs 45a, 55a, b.— Rowe & Gates 1995: 394.

Material examined. Ie Island (RUMF-ZE-02068[1]): “entrance” of the “Unnamed cave”, under coral rubble, approximately 18 m depth, 24 June 2017.

Distribution. North western Australia. Depth range 9– 180 m.

Remarks. This specimen present intermediate features of C. calista H. L. Clark, 1938 and C. granulifera . H. L. Clark, 1909. The features of C. callista are: dorsal arm plates are as wide as long on proximal portion of the arm, arms on proximal portion of the arms are flattened, peripheral edge of aboral disc on proximal portion of arms are convex, and length of arm spines are half of the corresponding arm segment. Whereas those of C. granulifera are: dorsal arm plates are slightly wider than long, arms on proximal portion of the arms are cylindrical, peripheral edge of aboral disc on proximal portion of arms are flat, and length of arm spines are shorter than those of C. callista (see also A. M. Clark & Rowe, 1971). Our specimen (RUMF-ZE-02068) have slightly wider dorsal arm plate on proximal portion of arms, cylindrical arms on proximal portion of arms; convex peripheral edge of aboral disc, and arm spines half length of the corresponding arm segment. Absence/presence of color band on oral arms is diagnostic character to distinguish C. callista and C. granulifera ( A. M. Clark & Rowe, 1971) . However, color of oral arm of our specimen have completely diluted by ethanol fixation and living color has not photographed. We here tentatively this specimen referred as C. cf. callista because its color pattern is more similar to C. callista . The type material of C. callista was collected from northern Australia and of C. granulifera was collected from Mauritius, and occurrence of this specimen in Japanese water is an extension of their range. Given the geographical gap between Japan and Australia and Mauritius, they are possibly different taxa. Or, emphasis on existence of the intermediate feature of our specimen indicates that these two species are conspecific. To clarify this, further morphological observations based on richer materials and molecular analysis are required.

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).