White Starfish

Coscinasterias tenuispina (Lamarck)

Asterias tenuispina Lamarck, 1816:561.–Perrier, 1875c:306.

Asteracanthion tenuispinus.–Muller and Troschel, 1842:16, pl. 1: fig. 1.–Perrier, 1869:32, pl. 1: figs. 3–3c.–Lutken, 1859:95.

Asterias (Stolasterias) tenuispina.–Sladen, 1889:565, 583.–Verrill, 1907:324 [280], pl. 34: fig. 2.

Coscinasterias tenuispina.–Verrill, 1914:45; 1915:19, pl. 26: fig. 2, pl. 27: fig. 4.–Gray, Downey, and Cerame-Vivas, 1968:159, fig. 38.

Asterias atlantica [part] Verrill, 1868:368.–Rathbun, 1879:144.

This species has a small disc and a variable number (5–10, usually seven) of long, angular arms of unequal length. It is fissiparous. The dorsal plates are thick and large and generally four lobed, forming an open meshwork. The carinal row is well marked, and most of the carinal plates bear a long, strong, movable, aciculate spine. The specimen before me is a juvenile, and has only a few dorsolateral plates, but larger specimens usually have one or two regular rows of dorsolaterals, armed like the carinal plates. The superomarginal plates bear an irregular patch of fine glassy tubercles, and alternate plates bear a sturdy aciculate spine, longer than that of the dorsal plates. The inferomarginals are trilobate and bear two oblique spines similar to those of the superomarginals. This juvenile specimen has no interactinal plates, but larger specimens usually have a single row of unarmed interactinals. The small, crowded adambulacral plates bear a single, long, slender spine. All spines above the inferomarginals bear a dense wreath of small, crossed pedicellariae; this juvenile specimen has only a few small, straight pedicellariae within the groove, but in larger specimens these are frequently large and abundant on all surfaces. The adambulacral spines and the inner, or actinal, inferomarginal spines are without pedicellariae. The disc dorsum is plated with large, heavy, irregularly shaped plates, most bearing a single large spine.

On the specimen before me, there are six round, raised madreporites, covered with coarse gyri.

This tropical-subtropical amphi-Atlantic species is common in the Mediterranean, and has been found at most of the islands in the Atlantic from Bermuda to St. Helena. Its depth range is unknown, but is quite possibly very great.

MATERIAL EXAMINED.–Silver Bay Station 2010 (1) [R=30 mm, r=4 mm, Rr=1:7.5].

Coronaster Perrier

Coronaster Perrier, 1885c:13. [Type, by original designation, C. parfaiti Perrier.]

Heterasterias Verrill, 1914:46. [Type, by original designation, Asterias (Stolasterias) volsellata Sladen.]

Rays 9–11; prominent, well-spaced acicular abactinal and marginal spines; large, straight, spatulate, unguiculate pedicellariae; abactinal skeleton with large square meshes; conspicuous wreath of small, crossed pedicellariae around spines; abactinal skeleton much reduced.

Only one species is known from the western Atlantic.

Coscinasterias tenuispina is a starfish in the family Asteriidae. It is sometimes called the blue spiny starfish or the white starfish. It occurs in shallow waters in the Atlantic Ocean and the Mediterranean Sea.