Zoroaster fulgens Wyville Thomson 1873

Zoroaster fulgens Thomson

Zoroaster fulgens Thomson, 1873:154.–Studer, 1884:23 den, 1889:694.–Bell, 1893:88.–Perrier, 1894:116.–Verrill, 1895:205.–Koehler, 1895:442; 1896:42.–Chun, 1900:489, fig.–H. L. Clark, 1901:237.–Nichols, 1903:251.–Schmidt, 1905: 22.–Grieg, 1907a:46; 1932:24.–Downey, 1970b: 15.

Zoroaster ackleyi Perrier, 1880:436; 1881b:59; 1881a:272; 1881 b: 1; 1894:117.–Verrill, 1895:205.–H. L. Clark, 1901:237.–Fisher, 1928a:491.

Non Zoroaster ackleyi.–Wood-Mason and Alcock, 1891:14.

Zoroaster trispinosus Koehler, 1895:442; 1896:42, figs. 14, 15.

Zoroaster bispinosus Koehler, 1909b: 136.

A five-lobed centrodorsum, eight primary radials (in overlapping pairs), and five large interradials, plus five large first carinals, make up the disc dorsum. The anus is between the centrodorsum and two primary radials, which are single rather than being paired like the other six. The anal pore is surrounded by small, flattened spines. Small pedicellariae may be scattered over the disc. The madreporite is small, flat, channeled, and located just distal to a primary interradial. Each carinal plate on the arms has two lobes on each side and overlaps the carinal plate proximal to it. Transversely, the carinals overlap the adradials, and the superomarginals overlap both the adradials and the inferomarginals. Below the inferomarginals are 6–2 rows of actinolateral plates (six near the disc, becoming two by the end of the arm). Each actinolateral plate bears a long, slender, appressed spine, directed upward, and mounted on a horseshoe-shaped tubercle, plus numerous small sacculate spinelets. The inferomarginals are similarly armed. The superomarginals and carinals frequently (but not always) bear a stout, erect central spine or tubercle, and these plates, as well as the adradials, are covered with small spinelets. The carinals are broader than long proximally and longer than broad distally.

The superambulacral plates are very small and do not extend beyond about the middle of the arm. The tube feet are in four rows proximally, becoming two rows less than halfway out on the arm. They are stout, conical, terminating in a small suckered disc (except for those actually within the peristomial cavity, which have large suckered discs), and the ampulae are double. The adambulacral plates are alternately carinate and noncarinate; the carinate adambulacrals bear five spines, two long, slender furrow spines with many small, straight pedicellariae (a large duck-billed pedicellaria may replace the many small ones) and three outer spines which are similar to the three spines of the noncarinate adambulacrals; these small spines do not bear pedicellariae. The jaw of four fused adambulacral plates bears two short, stout oral spines on each side, in a row along the oral edge of the jaw, covered with small, straight pedicellariae, and behind them are two pairs of long, acute spines.

This species seems to occur all over the North Atlantic, in 200–2,000 fathoms.

MATERIAL EXAMINED.–Alaminos Stations: 3C/68-A-7 (1) [R=54 mm, r=7 mm, Rr=1.8]; 1/68-A-13 (2) [R=86 mm, r=8 mm, Rr=1.11]; 10B/68-A-3 (2) [R=85 mm, r=6 mm, Rr=1:14], Oregon Stations: 1537 (2) [R=75 mm, r=9 mm, Rr=1:8]; 2574 (4) [R=85 mm, r=7 mm, Rr=1:12]; 3561 (1) [R=200 mm (est.), r=21 mm, Rr=1:10]; 3560 (2) [R=210 mm, r=18 mm, Rr=1:11]; 5929 (5) [R=149 mm, r=14 mm, Rr=1:10]; 4413 (3) [R=177 mm, r=22 mm, Rr=1:8]; 2571 (1); 2202 (2); 2779 (1); 2824 (2); 2652 (10); 1538 (6); 382 (6); 2650 (5); 3654 (6) [R=71 mm, r=7 mm, Rr=1:10], Oregon II Station 10619 (1) [R=75 mm, r=7 mm, Rr=1:10].

With the characters of the family Brisingidae; the only family in the order is Brisingidae Sars, 1875.

The Brisingidae have many deciduous arms, sharply distinct from the small circular disc. The vertebralike ambulacral and adambulacral plates are not compressed, and the tube feet are biserial. The dorsal skeleton, confined to the proximal third of the arm, is weak and never reticulate. The abundant pedicellariae are crossed, never straight. The mouth plates are expanded, and the actinostome is large, with a broad peristomial membrane. Papulae are lacking or confined to the disc and/or genital region of the arms. The marginal and adambulacral spines are long, delicate, acicular, and ensacculate.

Zoroaster fulgens Thomson, 1873

Zoroaster ackleyi Perrier, 1883.

Zoroaster diomedeae Verrill, 1884.

Zoroaster trispinosus Koehler, 1895.

Zoroaster bispinosus Koehler, 1909.

DESCRIPTION.—A 5-lobed centrodorsum, 8 primary radials (in overlapping pairs) and 5 large interradials, plus five large first carinals, make up the disc dorsum. The anus is between the centrodorsum and 2 primary radials, which are single rather than being paired like the other 6. The anal pore is surrounded by small flattened spines. Small pedicellariae may be scattered over the disc. The madreporite is small, flat, channeled, and located just distal to a primary interradial.

Each carinal plate on the arms has 2 lobes on each side and overlaps the carinal plate proximal to it Transversely, the carinals overlap the adradials and the superomarginals overlap both the adradials and the inferomarginals. Below the inferomarginals are 6–2 rows of actinolateral plates (6 near the disc, becoming 2 by the end of the arm). Each actinolateral plate bears a long, slender, appressed spine, directed upward, and mounted on a horseshoe-shaped tubercle, plus numerous small sacculate spinelets. The inferomarginals are similarly armed. The superomarginals and carinals frequently (but not always) bear a stout erect central spine or tubercle, and these plates, as well as the adradials, are covered with small spinelets. The carinals are broader dian long proximally and longer than broad distally.

The superambulacral plates are very small and do not extend beyond about the middle of the arm. The tubefeet are in 4 rows proximally, becoming 2 rows less than half way out on the arm. They are stout, conical, terminating in a small suckered disc (except for those actually within the peristomial cavity, which have large suckered discs), and the ampullae are double. The adambulacral plates are alternately carinate and noncarinate; the carinate adambulacrals bear 5 spines, 2 long slender furrow spines with many small straight pedicellariae (a large duck-billed pedicellaria may replace the many small ones) and 3 outer spines which are similar to the 3 small spines of the noncarinate adambulacrals; these small spines do not bear pedicellariae.

The jaw, of 4 fused adambulacral plates, bears 2 short stout oral spines on each side in a row along the oral edge of the jaw, covered with small straight pedicellariae, and behind them are 2 pairs of long acute spines.