Clarkcomanthus comanthipinna ( Gislén, 1922 )

Obuchi, Masami, 2020, Shallow-water Comatulids (Echinodermata: Crinoidea: Comatulida) of the Ashizuri-Uwakai Sea, Shikoku Island, Southern Japan, Species Diversity 25, pp. 309-328 : 315

13. Clarkcomanthus comanthipinna ( Gislén, 1922) [Japanese name: Kohige-kushi-umishida]

Morphology. Centrodorsal small, thin discoidal, 2.0– 3.0 mm across; polar area flat, 0.6–0.8 times of centrodorsal diameter. Cirri up to XI, 16 segments, 10.5 mm long, arranged in single rows with gap; c5–8 longest, L/ W 1.5; distal 3–5 segments with weak aboral process or transverse bar. Radials exposed, length 30–40% of centrodorsal diameter. IBr series composed of 2 ossicles, and II–IVBr of mostly (3+4), rarely 2; each ray well separated. Arms 20–29; anterior arms up to 210 mm long, 1.7–2.1 times longer than posterior; 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 . Terminal combs present as far as P 2–4, consisting of 7–18 segments; tooth single, non-confluent, straight, widely spaced from adjacent one; terminal segments fused to sharp tip. Disk four to seven times wide of centrodorsal, with fleshy papillae on tip of anal tube.

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

Distribution. Sagami Sea ( Kogo and Fujita 2014) to southern Queensland, Australia ( Rowe and Gates 1995), and to New Caledonia ( Rowe et al. 1986).

Coloration in life. Various. Rays khaki to black; pinnules aborally white, often with yellow tip; dark mid-longitudinal line present on arms.

Remarks. This species is recognizable by restricted distribution of the terminal combs and combs with pointed tip. In some specimens examined here, the terminal combs occured as far as P 4. In specimens from Australia, they are more restricted, usually to P 2 ( Rowe et al. 1986).