Calyptrophora carinata, 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 : 11

Calyptrophora carinata , n. sp.

Figs. 1D , 5 A–H

Etymology. Named carinata (Latin for carinate or ridged), in allusion to the ridged nature of the body wall, opercular, and coenenchymal scales.

Type and Type Locality. Holotype: colony fragments and SEM stubs 2532-2535, USNM 1467625 . Type Locality: EX 1708-15-5, 28.69˚N, 161.67˚W (Mozart Seamount, Musicians Seamounts), 3659 m, 22 Sept 2017.

Material Examined. Type.

Description. The holotype, which now constitutes seven colony fragments, the largest of which is 20 cm in length, and a number of smaller branches, represents about one-third of the entire colony ( Fig. 1D ). Based on the in situ image, it is estimated that the intact holotype was about 31 cm wide. Branching is roughly uniplanar and dichotomous, although several branching nodes produce three to five branches at the same level (polychotomous), resulting in a slightly bushy aspect; distal branches are up to 11 cm long. The polyps are widely spaced (three whorls/cm), directed downward, and consist of pairs or whorls of three. Individual polyps are 2.3–2.6 mm in horizontal length; the whorl diameter is about 2.9 mm.

The basal scale is 1.0– 1.25 mm in height (including distal teeth) and bears two broad, flat teeth on its distal margin Fig. 5 D–E), the teeth being up to 0.45 mm in length and ridged on their inner surface. The basal scale bears multiple prominent dorsolateral ridges ( Figs. 5 C–D) as well as a basolateral ridge, the former continuing along the outer face of the basal teeth. The buccal scale is slightly shorter (0.95–1.1 mm in length) but is also strongly ridged, the ridges radiating from a dorsolateral mound on either side of the sagittal plane ( Figs. 5A, F ). The distal edge of the buccal scale is slightly serrate. No infrabasal scales are present.

The operculum is long ( Fig. 5B ), all the opercular scales ( Fig. 5G ) being quite elongate with a high L:W ratio. The abaxial operculars are 1.3–1.5 mm in length, with an L:W of about 3.1, and have multiple ridges on both their inner and outer surfaces, and a coarsely serrate margin. The lateral operculars are 1.1–1.2 mm in length with an L: W of 2.3–2.4. The adaxial operculars are 1.0– 1.1 mm in length and are quite slender (L:W = 3.2–4.5).

The coenenchymal scales ( Fig. 5H ) are elongate (up to 1.2 mm in length) and slender (L:W = 3.3–7.8). They bear coarse granules as well as a prominent (up to 0.15 mm in height) longitudinal ridge (i.e., a sail scale).

Comparisons. Having downward directed polyps ( wyvillei species complex) and multiple branching nodes (polychotomous), Calyptrophora carinata keys closest to C. wyvillei Wright & Studer, 1889 in the key, a widespread species known from New Zealand to the Hawaiian Islands at 784–1278 m ( Cairns 2012). However, C. wyvillei differs in many ways including having three to five polyps per whorl; non-ridged basal, buccal, and opercular scales; a lyrate branching mode; and a shallower distribution.

Remarks. A white anemone was attached to the colony nears its main stem.

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 5. Calyptrophora carinata, holotype: A–C, stereo views of abaxial, adaxial, and lateral sides of a polyp. D, lateral and inner view of a basal scale, showing outer ridges and inner articular ridge. E, articular ridge of basal scale. F, outer, lateral and inner views of buccal scale. G, opercular scales. H, coenenchymal scales. Scale bars in mm.