Narcissia ahearnae Pawson, 2007, new species
Creators: name: Pawson, David L.
Publisher: name: Zenodo
Year: 2007
Subjects: Biodiversity
Taxonomy
Animalia
Echinodermata
Asteroidea
Valvatida
Ophidiasteridae
Narcissia
Narcissia ahearnae

description: Narcissia ahearnae, new species
Figures 1–4
Diagnosis: Conspicuous, thick, carinal ridge, undulating in horizontal and vertical planes, at least from center of disc to mid­point of arms. Color red to scarlet, lighter below. Western Atlantic.
Material Examined: HOLOTYPE, Catalogue No. HBOM 073:00531, Harbor Branch Oceanographic Museum, 5600 U.S. 1 North, Fort Pierce, Florida 34946. R/V Seward Johnson, Johnson­Sea­Link I Dive 2011, Off Cockburn Town, San Salvador, The Bahamas, 24°03.72’N, 74°32.91’W, 130 meters, 25 April 1987, 1 specimen, collected by M. Adams. PARATYPES: (1) Catalogue No. HBOM 073:00532, Harbor Branch Oceanographic Museum, R/V Seward Johnson, Johnson­Sea­Link I Dive 1984, Off Freeport, Grand Bahama Island, The Bahamas, 26°32.89’N, 78° 45.29’W, 87 meters, 8 April 1987, 1 specimen, collected by M. Adams. (2) USNM E12440, 1/ 3 mile NE of Goat Island, east Andros Island, The Bahamas, 26 February 1971, 54 meters, coral rubble, 1 specimen, collected by Sue Abbott. (3) USNM E09736, R/V Silver Bay, off Cape Canaveral, Florida, 27°26’N, 78°57’W, 135 meters, 25 October 1961. (4) UM Catalogue No. 40.487, Eleuthera Island, The Bahamas, top of ledge, 53 meters, 11 September 1972, 1 specimen.
Description: Abactinal surface brick red to scarlet in life (figure 2), actinal surface lighter in color. Disk high, pyramidal, arms five, long, slender, more or less triangular in cross­section. At base, height of arm sometimes equals breadth of arm, but more commonly height is up to 1.5x arm breadth. Carinal ridge (Figure 1) in all specimens elevated, conspicuously undulating in horizontal and vertical planes from center of disk along arms approximately to mid­point of each arm. Ridge 3–4mm thick, composed of carinal plates along with several series of abactinal plates. Marginal plates conspicuous when specimen viewed from above, forming and defining ambitus; marginals covered with granules. Anus slightly off­center, protected by several spatulate spines. Madreporite typical of genus, placed approximately one­third of distance from apex to interradial margin.
Abactinal plates vary greatly in size, not typically in any regular series; at about mid­point of arm about 17 plates traverse abactinal arm surface. Granules on abactinal plates evenly but closely spaced, discrete, not forming a mosaic; granules usually short, peg­shaped, about 330 μm high and 200 μm in diameter, tapering distally to a blunt to sharp point. Some granules rounded distally, but most are pointed. Papulae single or paired, extremely numerous abactinally in radii and interradii, about seven papulae per mm2 (Figure 3, Upper). Papulae also present in small numbers among actinolateral plates. No pedicellariae found.
Actinal plates in six rows near arm base, rows disappearing rapidly along length of arm; a single row extends to distal extremity of arm. Granules on actinal plates similar to those on abactinals. Adambulacral furrow spines (Fig. 4, Upper) four, flattened, blade­like, not tapering, approximately 1.5 mm long and 0.3 mm wide; distal tips slightly thickened; oralmost spine in each group of four slightly wider than others. Towards mouth, furrow spines (Fig. 4, Lower) become broader, sometimes almost discoidal, with distal ends thicker. Subambulacral spines in two to three rows of four each, similar to adambulacral furrow spines in length, but slightly wider.
Depth Range: In Florida and Bahama Islands 53–135 meters. At Grand Cayman, British Virgin Islands, observed but not collected at 113–126m (T. Engen, personal communication).
Distribution: Known from off Cape Canaveral in Florida, The Bahamas, and Grand Cayman, British Virgin Islands.
Ecology: All Florida and Bahamas specimens were found on hard substrates with a thin veneer of fine sediment. T. Engen (personal communication) found two specimens in the Grand Cayman Islands on a “steep slope with much sediment and sand”.
Etymology: This species is named for Cynthia Ahearn, Museum Specialist and Collections Manager of Echinoderms at the National Museum of Natural History, Smithsonian Institution, in recognition of her achievements in curation of the echinoderm collection, her research on echinoderms, and in facilitating the research of so many visitors over the years. In regard to visitors, Cynthia and her husband John have opened their home and hearts to numerous short­term and long­term visitors to the Museum, and provided them with substantial assistance in other ways. Without this unfailing generosity on the part of the Ahearns, most of these visitors would not have been able to travel to Washington and study the echinoderm collections. Reverend John E. Miller, who first recognized this beautiful new species, heartily concurs in the selection of this species­name.
Remarks: Narcissia ahearnae differs markedly from its three congeners in possessing a prominent, elevated, undulating carinal ridge. The coterminously distributed western Atlantic species N. trigonaria has a perfectly straight carinal ridge, and the color is consistently “cream blotched with rust red” (Walenkamp, 1976; Clark and Downey, 1992). In addition, in N. trigonaria, the marginal plates are inconspicuous, pedicellariae are very common, the abactinal granules are flattened and angular, forming a mosaic pattern, and there are about three papular pores (Figure 3, Lower) per square mm, while in N. ahearnae marginal plates are conspicuous, pedicellariae are absent or rare, the abactinal granules are peg­like and pointed, not forming a mosaic, and there are about seven papular pores per square mm.
This distinctive new species is an interesting addition to the shelf echinoderm fauna of the western Atlantic. It is expected that further investigations will greatly expand the known distribution range of this species.
description: Published as part of Pawson, David L., 2007, Narcissia ahearnae, a new species of sea star from the Western Atlantic (Echinodermata: Asteroidea: Valvatida), pp. 53-58 in Zootaxa 1386 on pages 54-58, DOI: 10.5281/zenodo.175124