Renilla reniformis ( Pallas, 1766 )

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 : 53

Renilla reniformis ( Pallas, 1766)

( Figure 47 )

Pennatula reniformis Pallas, 1766:374 .

Renilla reniformis forma typica Deichmann, 1936:259.

Renilla reniformis .— Bayer 1961:301.— Cairns et al, 2002:36.

Material examined. SERTC S427 , 11.5 m, Charleston Harbor , South Carolina, April 22, 2004 . SERTC S745 , 5.5 m, Sullivan’s Island , South Carolina, May 13, 2004 . SERTC S 2262, 10 m, off Jacksonville , Florida, July 24, 2003 .

Remarks. This species is easily recognizable as the only leaf-shaped octocoral in the shallow SAB, and is well described by its familiar name, “sea pansy”. The frond (oozooid) is approximately as wide as it is long, with polyps (autozooids and siphonozooids) restricted to the upper surface. Sclerites are in the form of three flanged rods, which are longer in the frond than in the stalk. The color of the colonies and sclerites includes varying shades of rose and purple.

Renilla reniformis is distinguishable from its southern tropical counterpart, R. muelleri , by the shape of the frond, which is not conspicuously wider than long, and by the sclerites of the stalk, which are shorter than those in the rachis. Both species can vary in intensity of color. Colonies can be found in intertidal systems and tidal creeks, as well as deeper marine habitats with soft sediment. The species is well known for its ability to bioluminesce.

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

Atlantic distribution: North Carolina to Brazil, Caribbean, 1–72 m ( Deichmann 1936; Bayer 1961; NMNH collections; SERTC collection).

Figures

FIGURE 47. Renilla reniformis: A, live specimen (S427), whole colony (diameter approximately 22 mm); B, frond with expanded polyps, showing sclerites.