Leptogorgia species A

Horvath, Elizabeth Anne, 2019, A review of gorgonian coral species (Cnidaria, Octocorallia, Alcyonacea) held in the Santa Barbara Museum of Natural History research collection: focus on species from Scleraxonia, Holaxonia, Calcaxonia - Part II: Species of Holaxonia, families Gorgoniidae and Plexauridae, ZooKeys 860, pp. 67-182 : 67

Leptogorgia species A Figures 25A, B, 26 A–C, 27 A–D

[? = Leptogorgia tricorata Breedy and Cortés 2011]

Type locality and type specimens.

There is a need for further confirmation of species identification regarding SBMNH specimens, through examination of other definitively identified specimens, as well as the type specimens for L. tricorata (Holotype UCR 1833; Paratypes UCR 1834, 1835, 1836 and 1837). The holotype was collected in Cocos Island National Park, Isla Manuelita NW, taken on 8 September 2006 at a depth of 14 m. The paratypes were collected from Cocos Island National Park as well, either at Isla Manuelita or Roca Sucia.

Material examined.

~11 lots (see Appendix 1: List of material examined).

Description.

Colonies (Figure 25A) non-reticulate; main stem ~14 cm long, arising from thin, flat attachment structure; latter gives off generally dichotomous (or irregular), mostly lateral, few to moderate, elongated, sometimes slightly crooked branches; these may divide again, often not; upright growth pattern in most, overall giving colony the appearance of a candelabra. Stem and branches rounded, nearly uniform, 1.0-2.0 mm diameter, not including polyps. Branches bend outwards in broad curve at axils; terminal branches from 2.5-7.5 cm long, without division, blunt at end. Few branchlets, rounded and slightly crooked. (One lot, SBMNH 422334, a simple, single whip-like, unbranched to minimally branched fragment, where diameter tends to smallest measurements of range, length ~37 cm, but not complete; other fragments much shorter, as above). Stem, branches and branchlets covered on all sides with prominent conical polyps, when extended (Figure 25B); when contracted, nearly flush with branch surface; apertures circular. Polyps measure 0.2 mm tall (extended), 1.7 mm wide; spacing between them 2.0-2.5 mm apart. Arrangement of polyps does not delineate median groove. Color of all colonies, regardless of colony shape, bright lemon yellow or gold; most sclerites bright lemon-yellow or gold; the few straight, less warted sclerites, pale or colorless. Sclerite shapes (Figures 26 A–C, 27 A–D) not diverse; mostly spindles, heavily warted; warts form regular belts; belts either evenly spaced (six to seven belted rings) or belts much closer together, largest at middle of spindle and outwards toward spindle tips progressively smaller, creating in silhouette sclerites that appear in elongated diamond shape (Figures 26C, 27C); some few (Figure 27D) of these with dense triangular collection of warts at each end with very narrow, median waist; very few straight, not as heavily warted, spindles. In a comparison with images from Breedy and Cortés (2011, Figure 2), similarities between the sclerites shown in their image and the one included here in Figures 26C and 27 are strong, with exception of tentacular sclerites (rods); SBMNH specimens may be L. tricorata Breedy & Cortés, 2011.

Distribution.

From specimens examined within the California Bight, limited range from Cortes Bank up to California Channel Islands, but see also Breedy and Cortés (2011) and “Remarks” below.

Biology.

Barnacle galls present on a number of specimens (SBMNH 423084 and SBMNH 422903).

Remarks.

This assemblage of specimens still not identified with certainty; despite the apparent similarity with Leptogorgia tricorata Breedy & Cortés, 2011, it seemed unlikely that a species from the shallow waters of Cocos Island would be seen in the California Bight. Yet, its species name, using an adjective derived from the Latin root tricoratus-, meaning to make tricks, is applicable, as no one I spoke to who regularly collects within the Bight (LACSD, OCSD) recalled ever seeing this species. Nearly all specimens in the SBMNH collection were collected in southern California in 1940 and 1941. A few specimens more recently collected (recent being late 1970s) are also included in the collection. Since then, however, no specimens that might be this species have been encountered or reported in any collecting events to the present. All specimens examined have slightly thicker branch diameter than that seen in Thesea Duchassaing & Michelotti, 1860 (which they can resemble on a superficial level; this especially true of fragments of SBMNH 422334; one other specimen in collection, SBMNH 13304, from a station off Point Loma, is identical), and color that is generally bright lemon yellow-gold, with very markedly colored sclerites, which display a very angular, elongated diamond-shape (refer to Figures 26C, 27C here and Figure 2 in Breedy and Cortés 2011). None of the large, spheroidal bodies common to Thesea were seen in these specimens; Thesea was eliminated as a possibility. What prevents a positive identification (as L. tricorata ) was a difference in aperture shape (circular vs. oblong) when polyps are contracted and complete absence of the tentacular rods, characteristic of L. tricorata . Multiple sclerite arrays were prepared, none of which displayed even a hint of the tentacular rods. While the material is older, it is in very good shape, having always been kept as wet specimens, with no evidence of formalin contact. Until further specimens can be found and collected from waters in southern California, within the Bight, and thoroughly examined, it seemed best to place these in the genus Leptogorgia without species designation ( L. tricorata does seem a strong possibility; however, lack of tentacular scleritic rods is problematic).

An additional piece of information regarding L. tricorata can be found in the work of Soler-Hurtado et al. (2017). Based on molecular analysis, they have proposed that L. tricorata should now be considered a derived form in the genus Pacifigorgia Bayer, 1951 (see page 226, Soler-Hurtado et al. 2017). Cordeiro et al. (2018d) does not show this proposed emendation of the genus Pacifigorgia in the WoRMS Data Base; L. tricorata , however, is shown as an accepted species in the genus Leptogorgia . I would add that the branching morphology in the SBMNH specimens is not reflective of branching patterns usually seen species of Pacifigorgia .