Chrysogorgia scintillans Bayer and Stefani, 1988

Cairns, Stephen D., 2018, Deep-Water Octocorals (Cnidaria, Anthozoa) from the Galapagos and Cocos Islands. Part 1: Suborder Calcaxonia, ZooKeys 729, pp. 1-46 : 20-22

Chrysogorgia scintillans Bayer and Stefani, 1988 Figures 3d, 13

Chrysogorgia curvata Nutting 1908: 591, pl. 45, fig. 9.

Chrysogorgia scintillans Bayer and Stefani 1988: 270-276, figs 11-12.

Material examined.

JSL-I-1927, 1 colony and SEM stubs 2327-2331, USNM 89377; JSL-I-1942, 1 colony, USNM 1160577; JSL-I-3925, 1 colony, USNM 1409700; holotype.

Types.

The holotype is deposited at the NMNH (USNM 25371).

Type locality.

Alb-4153: between Kauai and Moku Manu, 1758-1937 m deep.

Distribution.

Galápagos: between Isabela and Santiago; Cocos Island, 628-768 m deep. Elsewhere: Hawaiian Islands, 1758-1937 m deep.

Description.

The colony is biplanar (perhaps multiplanar), the largest colony examined (JSL-I-1927, Figure 3d) being 25 cm in height and 10 cm in width, and is somewhat bushy. The branching is dichotomous, the length of the internodes 6-7 mm, each internode bearing only one or sometimes two polyps. The polyps are 2.3-2.8 mm in height and project perpendicular to the branches (Figure 13 a–c), having a relatively narrow body wall column and a much larger distal crown, made larger by the projecting sclerites that support the tentacles. The axis is a metallic bronze in color.

The body wall scales (Figure 13c, d) are transversely arranged and slightly curved to fit the circumference of the polyp. The body wall scales, called “slippers” by Bayer and Stefani (1988), are up to 0.65 mm in length and 0.07-0.10 mm in width, resulting a L:W ratio ranging from 4.5-6.0; these scales are quite thin (about 0.03 mm). Some body wall scales are often slightly irregular in shape but usually rounded on their distal ends; their inner and outer faces are smooth and their edges rounded. The tentacular scales (Figure 13e) are similar in shape to the body wall scales but somewhat smaller, i.e., 0.35-0.45 mm in length. The base of each tentacle bears a distinctive tear-dropped shaped region about 0.4 mm long and 0.18 mm in width that is devoid of sclerites (Figures 13a-c). These regions are surrounded by flattened scales that project around the lower edge of the tentacle and thus forming a support for it. These scales sometimes have a root-like or lobate base (Figure 13f). The pinnular scales (Figure 13g) are 0.20-0.25 mm in length and are similar to the body wall scales, except that they have slightly serrate marginal edges. The coenenchymal scales (Figure 13c) are indistinguishable from the body wall scales, and are arranged longitudinally parallel to the branch axis.

Comparisons.

Chrysogorgia scintillans belongs to "Group C" sensu Versluys (1902) (Table 1), i.e., species having sclerites in the form of scales in both tentacles and body wall. Currently there are 18 species known in this grouping ( Cairns 2001; Pante and Watling 2011), three of which, including C. scintillans , having flabellate or multi-flabellate colonies and non-spiral branching. As noted by Bayer and Stefani (1988: key), C. scintillans is most similar to C. electra Bayer and Stefani, 1988, another flabellate species, but differs in having larger polyps, smaller projections beneath the tentacle bases, and slightly different shaped to their body wall and coenenchymal scales.