Two Spined Sea Star

Astropecten duplicatus Gray

Astropecten duplicatus Gray, 1840:185; 1866:3.–Perrier, 1876b:271.–Verrill, 1915:165, pl. 22: fig. 2, pl. 23: figs. 1, 2.–H. L. Clark, 1898a:5.–Gruvel, 1909:1018.–Boone, 1928: 5.–Fontaine, 1953: pl. 181; fig.–Cherbonnier, 1956:322–323; 1959:108–109, fig. 1.–Caso, 1961:27–29, fig. 4.–Gray, Downey and Cerame-Vivas, 1968:144, fig. 16.

Astropecten valenciennii Muller and Troschel, 1842:68.

Astropecten variabilis Lutken, 1859:51.–Verrill, 1867:343.–A. Agassiz, 1869.–Field, 1893:82.–Loriol, 1899:16, pl. 2.

Astropecten articulatus duplicatus.–Roa, 1967:277, fig. 6.

The five arms of this species are of moderate length and taper to a rather acute point. The paxillar area on the arms is about twice the width of the superomarginal plates. Paxillae are in regular transverse rows on the arms, and bear 15–25 capitate spinules. The superomarginal plates are higher than wide, extending above the paxillar surface, and the midportion of each plate is covered with spherical granules, while the sides bear numerous uniform fine blunt spinules. In the interradius, the first pair of superomarginals (and usually a few on each side of them) bear a stout tuberculate spine on the inner edge of the upper surface; superomarginals on the arms may bear a similar smaller spine on the outer edge of the upper surface. The inferomarginal plates extend beyond the superomarginals; each bears a single large, flattened spine and beside it a much smaller spine. Below, the inferomarginal plates bear a dense covering of flattened spines and spinules. The central furrow spine of the adambulacral plates is laterally flattened, with a rounded tip, and flanked by two shorter truncate spines. Behind the furrow spines are two truncate spines, the distal one large and flattened in the plane of the groove. Behind these are 2 or 3 small spines. The mouth plates are thickly covered with small blunt spines. The madreporite is small, round, evenly covered with deep gyri.

This spinous Astropecten ranges from shallow water to over 300 fathoms; it occurs all over the Gulf of Mexico and the Caribbean, and north to Cape Hatteras.

MATERIAL EXAMINED.–Oregon Stations: 3602 (1) [R=19 mm, r=7 mm, Rr=1:3]; 4089 (2) [R=15 mm, r=4 mm, Rr=1:4]; 2243 (1) [R=20 mm, r=5 mm, Rr=1:4]; 3555 (2) [R=29 mm, r=7 mm, Rr=1:4]; 5920 (12) [R=34 mm, r=9 mm, Rr=1:4]; 4472 (2) [R=33 mm, r=6 mm, Rr=1:5]; 150 (27) [R=15 mm, r=5 mm, Rr=1:3]. Oregon II Station 10499 (3) [R=2 mm, r=5 mm, Rr=1:4]. Silver Bay Station 1953 (2) [R=45 mm, r=11 mm, Rr=1:4].

Astropecten duplicatus, the two-spined sea star, is a starfish in the family Astropectinidae. It is found in the eastern Atlantic Ocean, the Caribbean Sea and the Gulf of Mexico.