Anneissia solaster (A. H. Clark, 1907 )

Obuchi, Masami, 2020, Shallow-water Comatulids (Echinodermata: Crinoidea: Comatulida) of the Ashizuri-Uwakai Sea, Shikoku Island, Southern Japan, Species Diversity 25, pp. 309-328 : 314-315

11. Anneissia solaster (A. H. Clark, 1907) [Japanese name: Utena-umishida]

Morphology. Centrodorsal thick discoidal, 5.4–7.3 mm across; polar area 0.7–0.9 times of centrodorsal diameter, with slight depression at center in large specimen. Cirri XVII–LI, up to 23 segments, 24.0 mm long, arranged in one, partly two rows; c5–8 longest, L/ W 1.8; distal ten segments with aboral process. Radials invisible. IBr series composed of 2 ossicles, IIBr of 4(3+4), and IIIBr of 4(3+4). Arms 20–29, usually 90–125 (up to 150) mm long; brachials shorter than broad, especially in distal half arms, with distal ends everted and spinous; 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; distal end of basal segments conspicuously everted and spinose . Terminal combs present as far as P 2–3, consisting of 7–20 segments; teeth single, non-confluent, straight, blade-like; terminal segments fused to sharp tip. Disk two to three times as wide as centrodorsal, with fleshy papillae on anal tube.

Posture. Likely nocturnal. Hiding under overhangs or between foliose corals. Some arms extended in multidirectional posture at nighttime.

Coloration in life. Three patterns: first with ivory arms, pinnules distally dark orange, brown centrodorsal, and orange cirri; second uniformly dark purple to dark brown; third uniformly light yellow.

Distribution. Noto Peninsula, northern Japan ( Kohtsuka and Kogo 2001) to off Amami Islands, East China Sea ( Kogo and Fujita 2005).

Remarks. This species is recognizable by the number of arms being less than 30, and basal segments of proximal pinnules with spinose projection.