Comanthus wahlbergii ( Müller, 1843 )

Mohammednowshad, B., Idreesbabu, K. K., Parameswaran, Usha V., Messing, Charles G. & Sureshkumar, S., 2020, The Shallow-water Crinoid Fauna of Lakshadweep Atolls, North-western Indian Ocean, Zootaxa 4789 (1), pp. 247-265 : 251-252

Comanthus wahlbergii ( Müller, 1843)

Alecto wahlbergii Müller, 1843:131 .

Actinometra wahlbergii: Dujardin & Hupé, 1862:211 .

Comanthus samoana: A.H. Clark, 1911b:181 (part); 1913a:17 (part).

Comanthus wahlbergii: A.H. Clark, 1912:95 ; 1913a:16; 1931:531, 588–593, pl. 65 (fig. 183). Rowe et al. 1986:204, 225 (fig. 6D–H), 228–32; Summers et al., 2017:182 (fig. 15D), 183 (fig. 16).

Comanthus samoanus: A.M. Clark & Rowe, 1971:6 , 16 (part).

Material examined.— Eastern outer reef of Agatti I., 10.860N & 72.202E, 17 m, 11 Nov 2018, Mohammed Nowshad, coll. (1, MTRLDST E0231).

Diagnosis.— A species of Comanthus with 10–38 arms to ~ 110 mm long; anterior arms usually longer than posterior arms; cirri XIII-XL, 12–18 cirrals; radials mostly hidden by well-developed, discoidal centrodorsal; IIBr and following division series usually 4(3+4), sometimes 2; proximal pinnules decreasing in length from P1 to P3. PD comb of 5–13 teeth; bases of adjacent teeth usually in contact; smaller secondary teeth present or absent; distal pinnule segments smooth or with abambulacral spines (A.H. Clark, 1931; Rowe et al., 1986).

Habitat.— The specimen was found in a crevice.

Description of survey specimen ( Figure 2G ).— Arms 26, to 90 mm long; centrodorsal a thin, circular disc, 2.5 mm across, with aboral surface flat or slightly concave. Cirri well developed, XII, 10 mm long, with 11 segments. First cirral very short; those following gradually increasing in length, so that c5 or c6 is twice as long as its proximal width; those succeeding decreasing in length; c8 or c9 with L:W 1.0 or slightly less. C5, c6, or c7 (usually c6) a wellmarked transition segment; middle and following cirrals with aboral edge slightly everted, becoming a transverse ridge on distal few segments; opposing spine blunt and forked. Radials concealed, but IBr series visible. IIBr series all 4(3+4). Proximal pinnules decreasing in length from P1 to P3. Color: rays orange with dark brown articulations and pinnules; cirri brown, becoming paler distally, with white tips; centrodorsal dark brown with most of the aboral pole white.

Distribution.— From South Africa in the west to Samoa in the east, including Lakshadweep, ANI, Indonesia, Philippines, Papua New Guinea, northern Australia (Garden Island, WA, to Mooloolaba, QLD), Lord Howe Island, New Zealand, Admiralty Islands, New Caledonia, Guam and southern Japan ( Rowe et al.1986; Rowe & Gates, 1985; Messing 1998a; Kogo 1998). Depth range: shoreline to 103 m (A.H. Clark, 1931; A.M. Clark, 1972; Rowe, et al., 1986).

Remarks.— This is the first record of this species from Lakshadweep waters. A.M. Clark (1972) distinguished two subspecies from its western range: C. w. tenuibrachia A.M. Clark, 1972, from Madagascar, and C. w. serrata ( Gislén, 1938) from South Africa.

Figures

FIGURE 2. A‒D. Comaster schlegelii. A–B.MTRLDST E0225, aboral view showing centrodorsal, cirri, brachitaxes, and proximal arms (A) and in situ (B). C–D. MTRLDST E0224, aboral view showing centrodorsal lacking cirri, brachitaxes, and proximal arms (C) and in situ (D). E. Himerometra robustipinna, MTRLDST E0227, in situ. F. Phanogenia typica, MTRLDST E0223, aboral view showing centrodorsal, brachitaxes and proximal arms. G. Comanthus wahlbergii, MTRLDST E0231, oblique aboral view showing centrodorsal, cirri, brachitaxes, and proximal arms.