Primnoidae (Cnidaria: Octocorallia: Calcaxonia) of the Okeanos Explorer expeditions (CAPSTONE) to the central Pacific Author Cairns, Stephen D. text Zootaxa 2018 2018-12-17 4532 1 1 43 journal article 27764 10.11646/zootaxa.4532.1.1 b3fb460f-20b4-4c62-98ea-a07d901bbfc0 1175-5326 2614967 4E9D0908-0933-48AF-A6ED-F3B8D39E8994 Calyptrophora pourtalesi , n. sp. Figs. 1F , 7 A–L Etymology . Named in honor of Count Louis François Pourtalès ( 1824–1880 ), early contributor to our knowledge of deep-sea Scleractinia, Stylasteridae, and Octocorallia ( Agassiz 1905 ), and author of the closely related species C. trilepis . Type and Type Locality . Holotype : colony and SEM stubs 2505-2508 , USNM 1453726 . Type Locality: EX 1703-8-01 , 0.210˚N, 176.48˚W (off Baker Island, Phoenix Islands ), 437 m , 16 March 2017 . Material Examined . Type . Description . The holotype ( Fig. 1F ) now consists of two branch fragments, each about 23 cm in height, which display equal, dichotomous branching, the distance between each bifurcation about 3–4 cm . Polyps are directed upward ( Fig. 7 B–C) and are arranged in whorls of four or five (seven or more on larger-diameter branches), 4–4.5 whorls occurring per cm branch length; the whorl diameter is about 3.5 mm . Individual polyps are 2.0– 2.4 mm in horizontal length. The fused basal scale ( Figs. 7D, G ) is 1.3–1.4 mm in height, projecting only slightly ( 0.06–0.10 mm ) beyond the articular ridge as a thin shelf ( Fig. 7G ), but not expressed as a spine or tooth. The articulating ridge is distinct and because of the short basal shelf, can be seen even from the outer surface of a bent polyp ( Fig. 7F ). The fused buccal scale ( Fig. 7D ) is larger ( 1.7–1.8 mm in length), having a rounded, finely serrate distal edge, the serrations being equilateral triangles about 8 µm in height ( Fig. 7H ); there is essentially no cowl. The outer surface of both types of body wall scales is uniformly covered with low granules. There is one pair of prominent, crescent-shaped infrabasal scales ( Figs. 7C, I ), which may be up to 1.3 mm in length and 0.45 mm in maximum height; often each bears one or more vertical radiating low ridges. The operculum is quite low ( Fig. 7J ), almost flat in the contracted condition, the opercular scales ( Figs. 7K ) being relatively similar in shape and size; they have a concave outer surface and a keeled inner surface. The adaxial operculars are symmetrical, 0.72–0.89 mm in length, and have an L:W of 1.25–1.40; the lateral, slightly asymmetrical operculars are 0.65–0.80 mm in length, with an L:W of 1.15–1.30; and the adaxial operculars are also asymmetrical, 0.50–0.60 mm in length, with a very broad base resulting in a low L:W of 0.85–1.00. The coenenchymal scales ( Fig. 7L ) are elongate (L:W = 3.5–7.5), slightly irregular in shape, flat, and bear low granules (no ridging) like the body wall scales. FIGURE 7. Calyptrophora pourtalesi , holotype: A , stereo opercular view of two polyps. B–C , stereo views of abaxial and lateral sides of a polyp. D , stereo view of inner side of buccal scale. E , basal scale. F, articulation of basal to buccal scale. G , distal margin of a basal scale. H , distal edge of a buccal scale. I , infrabasal scales. J , polyp operculum. K , opercular scales. L , coenenchymal scales. Scale bars in mm. Comparisons . Calyptrophora pourtalesi , a member of the japonica species complex, is remarkably similar to C. trilepis (Pourtalès, 1868) , a species known only from the tropical western Atlantic from 593–911 m , and might even be considered as a sister species. C. trilepis differs only in having smaller polyps ( 1.3–1.6 mm in length, and thus a smaller whorl diameter) and fewer polyps per whorl (2–4). Although redescribed by Bayer (2001) , both species are known from very few specimens and thus comparisons are tentative. Within the Pacific C. pourtalesi is most similar to C. japonica Gray, 1866 , but that species has a biplanar, bipectinate colony. Distribution . Known only from the type locality.