Capillaster multiradiatus (Linnaeus, 1758)

Meyer, David L., Hoggett, Anne, Huang, Danwei, Rouse, Greg W., Vail, Lyle, Yen, Ying-Hsuan & Messing, Charles G., 2025, A new species of the feather star Capillaster within C. multiradiatus species complex (Crinoidea, Comatulidae) in Palau and the Great Barrier Reef, Zootaxa 5647 (3), pp. 275-288 : 285-286

Capillaster multiradiatus , based on 2-1-83-1

Australian Museum J.31561—PV560662 11-1-83-1 Lizard Island GBR

Australian Museum J.31562—PV560664 VII-3-83-8 Rib Reef GBR

Australian Museum J.31563—PV560665 VII-4-83-2 John Brewer GBR

Australian Museum J.31564—PV560663 V-27-83-1 Davies Reef GBR

Australian Museum J.31565—PV560666 VIII-24-76-10 Lizard Island GBR

Color in life ( Fig. 2 A, B ): arms and pinnules vary from golden brown on abambulacral side, cd and cirri darker brown to dark brown or olive drab, pinnules with white tips, ambulacra brown, fringed with white flanks on either side of ambulacra, both in arms and pinnules; white has dark speckles creating a frosted appearance.

Skeletal morphology. From notes on 2-1-83-1 and spreadsheet coding, Table 1 .

Fig. 2 C–F ; 19 arms, ~ 110 mm length; 6 II brachials have 4 ossicles, 3 having 2 ossicles.

Centrodorsal subpentagonal in aboral view with distinct polar indentation, ~ 4.5 mm diam. This feature is present in most BR specimens but in some specimens it is less distinct, probably a result of variation that requires further study.

Cirri 19, with 23–25 segments in single row, with abambulacral spinose clumps ( Fig. 6 C–E ); 15–17 mm long; longest segment is 6mm, following segs. decrease in length, becoming broader than long. Antepenultimate cirrus seg, shorter than opposing spine on penult. segment.

Syzygies: 1 st at 2+3; 2 nd at 11+12, 15+16, 16+17, 16+17, 18+19; distal intersyzygial interval variable ( Fig.6 C, D ).1 st pinnule on free arm at Br 1.1 st triangular Br is ~Br 8. Comb-bearing oral pinnules extend distally beyond P6*, ~5 comb teeth confluent with exterior edge of pinnular, teeth triangular, curved inward ( Fig. 6 F )*. Proximal brahicals both rectangular or slightly wedge-shaped in aboral view becoming rectangular distally; distal edges of brachials slightly everted and spinous to finely spinose.

*The distinction suggested here between C. crypticus sp. nov. and C. multiradiatus is tentative because examination with the binocular microscope was very difficult. It was hard to determine the number of oral pinnules bearing combs and precise number of comb teeth with certainty. However, we are confident that in the new species, combs are present only to P6, but in C. multiradiatus combs are present distally to ~P7 or P8. If confirmed by further study, and exact extent of comb-bearing pinnules and the number of comb teeth could provide additional differences between the new species and C. multiradiatus , besides the presence or absence of the aboral pit in the centrodorsal.

Figures

FIGURE 2. A, Capillaster multiradiatus ss. Lizard Island, Great Barrier Reef, Australia, undisturbed in daytime. Note dark brown arm color. Photo courtesy of L.Vail and A. Hoggett, Lizard Island Field Guide. B, Capillaster multiradiatus ss. II-22- 83-27, South Island, specimen in daytime placed for photo. Note distinct aboral pit. C, Capillaster multiradiatus ss, (VIII- 24-76-10); outer reef between Bird Islet and South Island, near Lizard Island. Note distinct aboral pit. D, C. multiradiatus ss, Granite Bluff (II-1-83-1). (Embossing tape A marks A-ray.) E and F are cd from specimen in D. Note that this specimen was collected very close to site of C. crypticus sp. nov. (holotype, II-10-83-1, 2A, collected on different day). E. Centrodorsal of C. multiradiatus ss, aboral view, SEM, (from II-1-83-1). F, tilted view, SEM, same specimen, showing cirral facets. Note distinct aboral pit in E & F, same specimen as D.

FIGURE 6. A, Capillaster crypticus sp. nov. exposed by day, removed from reef infrastructure and photographed in life (VII- 3-83-9), Rib Reef, Central GBR. B, Capillaster crypticus sp. nov., same specimen as in A after fixation and fading of color. Embossing tape A marks A-ray. Note flat centrodorsal. C, Capillaster multiradiatus (VII-3-83-8) aboral view, note distinct pit at aboral center. Note that specimens in B and C were collected on same day at same reef, but B was one of two of the new species collected on Rib Reef during this daylight dive, exposed fortuitously by overturning coral slabs. C was fully exposed on Rib during same dive. D, closer view of C. aboral view oriented at 90 deg. clockwise from C. E, cirrus from Capillaster multiradiatus F, oral pinnule, Capillaster multiradiatus.