Ryukyuaster onnae Mah 2007

Mah, Christopher L., Kogure, Yoichi, Fujita, Toshihiko & Higashiji, Takuo, 2024, New Taxa and Occurrences of Mesophotic and Deep-sea Goniasteridae (Valvatida, Asteroidea) from Okinawa and adjacent regions, Zootaxa 5403 (1), pp. 1-41 : 34-35

Ryukyuaster onnae Mah 2007

FIGURE 13C–D

Mah 2007: 320

Diagnosis

Body form stellate.Approximately 16 marginals per interradius. Lateral edge of marginal plates with granular cover. Tubercular granules, granular spinelets on abactinal, marginal plate surface ( Fig. 13C ). Intermarginal pits present between central two to three interradial superomarginal–inferomarginal plate pairs. Pits bare, flanked by clavate spines, 3–4. Actinal intermediate plates covered by polygonal granules at R = 1.5 cm ( Fig. 13D ). Furrow spines three to five. Terminal plates enlarged.

Comments

Nearly all of the material for this species from Mah (2007) were collected from mesophoitc depths (40–60 m) with only two individuals from shallow water (2–4 m).

The new specimen from the Sulu Archipelago suggests that this species is much more widespread than was previously realized. Its mesophotic occurrence (51 m) and small size might explain why it has been recognized only recently.

Occurrence

Okinawa, Ryukyu Islands, Japan. 40–51.2 m.

Outside Japan. Sulu Archipelago (extension). 3– 67 m.

Material Examined

USNM E46165 Seragaki Beach , 1.3 km ENE of Maeki-zaki, Okinawa, Ryuku Islands , Japan. 45.75–48.8 m Coll. R.F. Bolland 16 Aug 1985. (1 dry spec. R=0.9, r=0.5)

USNM E53611 Horseshoe Cliffs, 1km WNW of Onna Village , Okinawa, Ryuku Islands, Japan. 26º30’N, 127º50’54E, 40–46 m (130–150 ft), Coll. R.F. Bolland 16 March 1985, 1 dry spec. R=1.1, r= 0.6 cm.

USNM E53706 Horseshoe Cliffs, 1km WNW of Onna Village , Okinawa, Ryuku Islands , Japan. 26º30’N, 127º50’ 54E, 47 m (155 ft). Coll. R. F. Bolland 20 Jan 1985, 1 dry spec. R=1.3, r=1.0.

WAM 1629.74 (1) SE of Capui Island, Sulu Archipelago, sand, Lithothamnion , 51.2 m. Coll. B.R. Wilson, Feb 19, 1964. 1 dry spec. R=1.7 r=1.0 cm.

Figures

FIGURE 13. Anchitosia queenslandensis & Ryukuaster onnae (Pentagonasterinae) A. USNM 1114607, Abactinal view. B. Actinal view. C. WAM 1629.74 (1) Abactinal view. D. Actinal view. Scale bars: A–B, 3.0 mm for C–D.