Leptogorgia setacea (Pallas, 1776)

Devictor, Susan T. & Morton, Steve L., 2010, Identification guide to the shallow water (0 - 200 m) octocorals of the South Atlantic Bight 2599, Zootaxa 2599 (1), pp. 1-62 : 49-50

Leptogorgia setacea (Pallas, 1776)

( Figure 44 )

Gorgonia setacea Pallas, 1766:182 .

Pterogorgia gracilis Verrill, 1868:359 ; Plate 4 figs. 2–3.

Gorgonia gracilis .— Verrill 1912:393; Plate 29 fig. 2; Plate 35 figs. 5–5a.

Gorgonia brasiliensis Verrill, 1912: 392 ; Plate 29 fig. 3; Plate 33 fig. 7; Plate 35 fig 7.

Not Xiphigorgia setacea .— Kükenthal 1916:502.

? Leptogorgia contorta Kükenthal, 1919:915

Leptogorgia trinidadensis Hickson, 1928:416 ; Plate 4 fig. 7; text fig. 37.

Leptogorgia virgulata Cowles, 1930:332 .

Leptogorgia setacea .— Verrill 1872:433.— Deichmann 1936:178; Plate 19 figs. 35–38.— Bayer 1961:218; Figs, 67, 68 a–d.— Cairns et al, 2002:35.

Material examined. SERTC S 1326, 12 m, off South Island , South Carolina, June 1, 2004 . SERTC S 2123, 21 m, off St. Catherine’s Island , Georgia, June 3, 2004 . SERTC S2715 , 18.3 m, off Sapelo Island , Georgia, May 28, 2006 .

Remarks. Leptogorgia setacea is usually unbranched and often completely unattached, or attached to a vacant bivalve shell. The single branch is usually between 2 and 4 mm in diameter and can reach 2 m in length ( Deichmann 1936). The polyp mounds are arranged in a single or multiple rows along the sides of the branch, and often are a darker color than the coenenchyme. The polyp mounds may be moderately prominent, or the apertures may be flush with the surrounding coenenchyme. Coenenchymal sclerites are in the form of acute, warty spindles reaching 0.2 mm in length and smaller disc spindles and capstans. Anthocodial rods are usually less than half the length of the large spindles. The colonies are purple, yellow, or pale lavender with dark purple polyp mounds.

This species shares many characters with L. virgulata , especially with regard to spiculation. Most L. setacea colonies are easily recognizable based on colony morphology, but if only fragments of colonies are available, close examination of the sclerites is necessary. Both L. setacea and L. virgulata are common along the southeastern coast of the US and penetrate into lower salinity habitats such as tidal creeks and bays.

There are numerous lots of this species in the NMNH from the shallow SAB.

Atlantic distribution: Chesapeake Bay to Florida, Gulf of Mexico, Colombia to Brazil 1–68 m (one record from Guyana indicates collection at 9245 m, but this is likely an error). Deichmann recorded specimens from Bahamas and West Indies, but no depth was mentioned ( Deichmann 1936; Bayer 1961; NMNH collections; SERTC collection).

Figures

FIGURE 44. Leptogorgia setacea: A, sclerites (S2123); a, b) spindles from coenenchyme; c, d) disk spindles from coenenchyme; e) anthocodial rod (scale bar = 0.02 mm); B, colony attached to a bivalve shell; C, section of stem; (scale bar = 3 mm).