Comanthus scintillus Obuchi and Fujita, 2017

Obuchi, Masami, 2020, Shallow-water Comatulids (Echinodermata: Crinoidea: Comatulida) of the Ashizuri-Uwakai Sea, Shikoku Island, Southern Japan, Species Diversity 25, pp. 309-328 : 313

6. Comanthus scintillus Obuchi and Fujita, 2017 [Japanese name: Hanabi-umishida]

Morphology. Centrodorsal thin, slightly raised from level of radials, 2.6–3.4 mm across; polar area flat, 0.7–0.8 times of centrodorsal diameter. Cirri weak, II–IX, up to 16 segments, 8.0 mm long, arranged in single row with gaps; c4–7 longest, L/W usually 1.3; dorsal 4–5 segments with aboral transverse ridge. Radials narrowly exposed, length less than 15% of centrodorsal diameter. IBr series composed of 2 ossicles, and II–IIIBr of mostly 4(3+4), rarely 2. Arms up to 38; anterior arms usually 150 mm long, 2.1–2.4 times longer than posterior ones; brachials shorter than broad, with distal ends everted; first arm syzygy at br 3+4; distal intersyzygial intervals 4. Comparative pinnule length PD>P 1 >>P 2 <P 3 <P 4 =P 5; PD and P 1 enlarged; middle segments of distal pinnules with fringing spines on distal end, but sometimes indistinct. Terminal combs present as far as P 11–18 at intervals, consisting of 6–11 segments; teeth single, confluent with lateral margins of pinnule segments, curved inward, basally contacted with adjacent one; terminal segment with discrete large tooth; proximal segment with transverse saucer-shaped tooth. Disk three to five times as wide as centrodorsal.

Posture. Dwelling within cracks or crevices, or between stony corals, with anterior arms in multidirectional posture.

Coloration in life. Uniformly red with small yellow spots scattered; distal arms sometimes densely spotted and almost yellow.

Distribution. Southern Izu Peninsula (H. Kohtsuka, personal communication) to Miyako Island, Ryukyu Islands ( Obuchi and Fujita 2017).

Remarks. This species is characterized by the restricted distribution of combed pinnules to the middle of its arms, and the presence of spines fringing distal ends of the segments of the distal pinnules. Its general appearance is close to C. parvicirrus and C. gisleni . The specimens identifiable as this species were collected in southern Izu peninsula and southern Kyushu (H. Kohtsuka, personal communication), which suggests this species is distributed in the temperate to subtropical zones.