Calyptrophora lyra, Cairns, 2018

Cairns, Stephen D., 2018, Primnoidae (Cnidaria: Octocorallia: Calcaxonia) of the Okeanos Explorer expeditions (CAPSTONE) to the central Pacific, Zootaxa 4532 (1), pp. 1-43 : 8-10

Calyptrophora lyra , n. sp.

Figs. 1B , 3 A–L

Etymology. Named lyra (Greek for lyre) in allusion to the lyrate colony shape.

Type and Type Locality. Holotype: colony and SEM stubs 2389-2392, USNM 1424218 . Type Locality: EX 1606-10-02, 18.4705˚N, 166.680˚E (guyot 50 km south of Wake Island), 1409 m.

Material Examined. Type.

Description. The holotype is uniplanar and distinctly lyrate in branching, although only a part of the colony ( Fig. 1B ) was collected and in situ photographs do not show the entire colony; the holotypic colony fragment measures 22 cm in length. Long (up to 12 cm in length) unbranched branchlets originate on the main branch at intervals of 14–19 mm, these branchlets growing parallel to one another in a plane. Polyps are directed downward and are arranged in whorls of four, being fairly closely spaced (3.5–4 whorls/ cm), the whorl diameter being 3.5–4.3 mm. Individual polyps are 2.3–2.8 mm in horizontal length, the contracted opercular scales pointing downward toward the branch. The polyps are orange; the axis is bronze.

The fused basal scale is 1.6–1.9 mm in length, including its two broad, flat, blunt distal teeth ( Figs. 3B , D–F), which constitute 0.45–0.55 mm of its length. The inner surface of the distal teeth is covered with several longitudinal, serrate to spinose ridges; the outer surface is uniformly covered with low spines, as is the outer surface of all the sclerites of this species. The articulating ridge is pronounced ( Figs. 3D, E ), and up to 0.95 mm in length. The fused buccal scale ( Fig. 3G ) is slightly longer (1.9–2.1 mm), terminating in a rounded (not lobate or toothed), finely serrate (serration about 8 µm in height, Fig. 3H ) margin that is produced into a very short cowl encircling the bases of the opercular scales ( Fig. 3C ). Both basal and buccal scales have an indication of a sagittal suture. There is one pair of prominent (up to 0.45 mm in maximum height), curved infrabasal scales ( Figs. 3 A–B, I–J), which meet on the abaxial side of the polyp.

The operculum ( Fig. 3C ) is relatively low, the opercular scales being thin, flat, and triangular in shape. The symmetrical abaxial operculars measure 1.08–1.15 mm in length and have an L:W of 1.4–1.5. The slightly asymmetrical lateral operculars measure 0.9–1.0 mm in length and have an L:W of 1.5–1.65. The symmetrical adaxial operculars measure about 0.75 mm in length, with an L:W of 1.15–1.35. All operculars ( Fig. 3K ) have a low longitudinal ridge on their distal inner face.

The coenenchymal scales ( Fig. 3L ) are flat and irregular in shape, up to 1.5 mm in greater length.As with all the other scales of this species, they bear a uniform coverage of small spines that are not arranged in lines or ridges.

Comparisons. Calyptrophora lyra belongs to the wyvillei species complex (sensu Bayer 2001), including eight to nine species that have their polyps oriented as facing downward (see key, couplet 1’): C. wyvillei Wright, 1885 ( New Zealand, Hawaii), C. agassizii Studer, 1894 (Galápagos) , C. reedi Cairns, 2018 (Galápagos) , C. clinata Cairns, 2007a (New England Seamounts), C. diaphana Cairns, 2012 ( New Zealand, 680–1113 m), C. distolos , n. sp. ( American Samoa and Guam), C. carinata , n. sp. (Musicians Seamounts), C. lyra , and some specimens of C. inornata Cairns, 2012 ( New Zealand, some of which are keyed in Cairns 2009). The new species is most similar to C. diaphana , both being lyrate in growth form and having very similar buccal scales, but C. diaphana differs in having: larger polyps; a much larger buccal cowl; basal scales that project well beyond the attachment to the buccals as a continuous only slightly indented single lobe, not as two broad teeth; only one (not a pair) abaxial opercular scale that is almost circular in shape (L:W less than 1); in general, stouter opercular scales; more elongate, almost rectangular, coenenchymal scales; and, in general, two pairs of infrabasal scales.

Remarks. During collection, the polyps of the colony were being grazed by a large orange seastar. Distribution. Known only from the type locality.

Figures

FIGURE 1. In situ images of various species: A, Callogorgia cracentis, holotype. B, Calyptrophora lyra, holotype (not in situ). C, C. diaphana, EX1606-9-1. D, C. carinata, holotype. E, C. clarki, EX1605-L3-6. F, C. pourtalesi, holotype. G, C. distolos, holotype. H, Candidella gigantea, EX1606-6. I, Macroprimnoa ornata, holotype. J, Narella virgosa, holotype. K-L, N. aurantiaca, holotype. M, N. merga, holotype. N, N. horrida, EX1703-2-3. O, N. fordi, holotype. P, N. calamus, holotype. Q, N. virgosa, paratype, EX1504-L4-9-4. R, N. macrocalyx, EX1606-7. S, N. hawaiiensis, EX1504-9-2. T, Paracalyotrophora hawaiiensis, EX1703-2-1. U, P. echinata, EX1703-10-1. V, P. spiralis, holotype. W, Plumarella circumoperculum, EX1603-2-3. X, Thouarella hilgendorfi, EX1605-L1-17.

FIGURE 3. Calyptrophora lyra, holotype: A–C, stereo views of abaxial, lateral, and adaxial sides of a polyp. D, stereo view of inner face of a basal scale showing the articular ridge. E–F, spines of basal scales. G, lateral and adaxial views of a buccal scale. H, serrate margin of a buccal scale. I, infrabasal scale in situ. J, an infrabasal scale. K, opercular scales. L, coenenchymal scales. Scale bars in mm.