Comatula cf. solaris Lamark, 1816

Es, Mekhova & Ta, Britayev, 2015, Soft substratecrinoids (Crinoidea: Comatulida) andtheir macrosymbionts in Halong Bay (North Vietnam), Raffles Bulletin of Zoology 63, pp. 438-445 : 439-441

Comatula cf. solaris Lamark, 1816

( Fig. 2a )

Comatula solaris Lamark 1816: 533 ; Clark AH, 1921: 233 pl.1 figs. 960–962; Clark & Rowe, 1971: pp. 6–7, 14, pl. 1 figs. 7, 8; Rowe & Gate, 1995: 148; Messing, 2015.

Material. South China Sea, Halong Bay, Katba Is., St. 1, 1–4 m depth, 30 April 2012 – 1 specimen ; St. 2, 10–15 m depth, 30 April 2012 – 15 specimens ; St. 3, 4–5 m depth, 1 May 2012 – 3 specimens ; St. 7, 0–3 m depth, 4 May 2012 – 3 specimens ; St. 8, 1–10 m depth, 6 May 2012 – 4 specimens .

Coloration. Uniformly brown with a pinkish tinge, red in alcohol.

Measurements. Ten arms 80–120 mm in length: 9–16 cirri 7–12 mm in length.

Taxonomic remarks. Genus Comatula consists of seven species with four having cirri ( Messing, 2015). Cirri arranged in one row around centrodorsal, numbers usually exceeding 10 ( Fig. 2 ). Number of cirrals usually less than 16. P1 and P2 have long combs with 20–26 confluent teethes. P3 and following pinnules without combs. Second and third basal segments of P2 with small ridge-like extensions on the aboral sides. Five of 10 arms without ambulacral grooves. These features are in accordance with diagnoses of C. solaris provided by Messing (2015). Closely related species, C. pectinata and C. tenuicirra have less number of cirri on 1–2 interradial corners.

Ecological notes. Common. Found both solitarily and in groups of three to seven individuals, on soft ground in burrows, recesses, or under dead bivalve shells; depth range 1–15 m. Probably nocturnal; during the day arms are usually folded. In some individuals arms were extended but did not form a filtration fan. Reported previously on soft substrate under a small rock ( Messing et al., 2006).

RAFFLES BULLETIN OF ZOOLOGY 2015

Symbionts. Polychaetes Hololepidella cf. laingensis Britayev, Doignon & Eeckhaut, 1999 , Myzostoma cf. fissum Graff, 1884; ophiuroid Ophiomaza cacaotica Lyman, 1871 ; gastropod Eulimidae gen. sp.; Amphipoda gen. sp.

Distribution. Vietnam, China, Singapore (Lane at al., 2000), North Australia, West India ( Clark & Rowe, 1971; Messing, 2014).

Figures

Fig. 2. Proximal ray articulations, branching patterns and arrangement of cirri: a, Comatula purpurea; b, Capillaster gracilicirrus; c, Amphimetra tessellata. IIBr and IIIBr division series. Scale bar = 1 cm.