Fromia monilis ( Perrier, 1869 )

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 : 19-21

Fromia monilis ( Perrier, 1869)

FIGURE 8A–E

Scytaster Perrier 1869: 62 (54)

Fromia japonica Perrier 1881

Fromia major Koehler 1895

Fromia H.L. Clark 1921: 46 ; Doderlein 1926: 19; Hayashi 1938: 425; 1973: 58; Clark & Rowe 1971: 62; Marsh 1977: 258; 1978: 222; Jangoux 1978: 296; Julka & Das 1978: 347; A.M. Clark 1993: 332; Rowe & Gates 1995: 82; Marsh & Fromont 2020: 237.

Diagnosis

Body stellate (R/r=3.8–5.0), arms elongate and triangular, disk small, interradial arcs acute ( Fig. 8A, D ). Granular cover continuous over abactinal and marginal plates surfaces, coarser on actinal surface ( Fig. 8B ). Abactinal plates weakly convex, especially on disk becoming more convex on arms. Superomarginal plates convex, uniform and contiguous interradially and proximally on arms alternating large and small plates distally from approximately midway along the arm ( Fig. 8A, C ). Furrow spines 2 to 3, subambulacral spines two with two series of 4 to 6 granules ( Fig. 8E ). Papulae single on corners of abactinal, marginal and actinal surfaces.

Comments

Fromia monilis is a widely occurring species throughout the Indo-Pacific ranging from the Central and South Pacific to the Indian Ocean, in tropical coral reefs from littoral to mesophotic depths where it feeds on algae and biofilm substrates ( Marsh & Fromont 2020). It is observed with relatively great frequency and is a mainstay of underwater photo guides and similar image-based identification resources for this region (e.g. Coleman 2007; Marsh & Fromont 2020) as well as online venues such as iNaturalist. These images display what appears to be the highly variable range of morphology and color, including differing abundance of abactinal plates across the arm; disk and arm size and width; variation of the color pattern, including white arms, red disk, and darkened arm tips (e.g. Coleman 2007). Examination of many specimens as well as analysis of DNA sequences suggests that Fromia monili s is composed of a wide-ranging cryptic species complex (G. Paulay, pers. comm.) It is apparently further confused with other species of Fromia , such as Fromia heffernani which possess similar coloration but differing actinal surface morphology.

Occurrence

Japan. Okinawa, Ryukyu Islands (herein) 46–59.0 m.

Outside Japan. Tropical Australia, from the Houtman Abrolhos, Western Australia to Ashmore reef, Timor Sea and the Great Barrier Reef, Queensland to Elizabeth Reef, Tasman Sea. Red Sea, Maldive Islands, Indonesia, Philippines to New Caledonia, Mariana Islands, Palau, Samoa and Fiji in the West Pacific. Taiwan, 0–100 m (following Marsh & Fromont 2020).

Material Examined

USNM E45562 1km WNW of Onna Village ( Horseshoe Cliffs ), Okinawa, Ryukyu Islands , Japan. 26.5 127.848, 52.0 m. Coll. R.F. Bolland, 27 Sept. 1986. 1 dry spec. R=2.9 r=0.6, 6 arms.

USNM E45569 1km WNW of Onna Village ( Horseshoe Cliffs ), Okinawa, Ryukyu Islands, Japan. 26.5 127.848, 53–59 m. Coll. R.F. Bolland, 16 Oct. 1985. 1 dry spec. R=3.0 r=0.8

USNM E45943 1km WNW of Onna Village ( Horseshoe Cliffs ), Base of vertical rock wall at reef edge. Okinawa, Ryukyu Islands , Japan. 26.5 127.848, 49.0 m. Coll. R.F. Bolland, 18 Aug. 1988. 1 dry spec. R=3.0 r=0.6

USNM E45962 1km WNW of Onna Village ( Horseshoe Cliffs ), Okinawa, Ryukyu Islands , Japan. 26.5 127.848, 49.0 m. Coll. R.F. Bolland, 27 September 1986. 1 wet spec. R=3.7 r=0.8

USNM E45921 1km WNW of Onna Village ( Horseshoe Cliffs ), Okinawa, Ryukyu Islands , Japan. 26.5 127.848, 58.0 m. Coll. R.F. Bolland, 21 June. 1987. 1 wet spec. R=2.1 r=0.5

USNM E45968 1km WNW of Onna Village ( Horseshoe Cliffs ), Okinawa, Ryukyu Islands , Japan. 26.5 127.848, 46.0 m. Coll. R.F. Bolland, 2 Sept. 1988. 1 wet spec. R=3.7 r=0.8.

USNM E50771 1km WNW of Onna Village ( Horseshoe Cliffs ). Okinawa, Ryukyu Islands , Japan. 26.5 127.848, 46.0 m. Coll. R.F. Bolland, 24 April 1984. 1 wet spec. R=1.6 r=0.3.

Figures

FIGURE 8. Fromia monilis USNM E45943 A. Abactinal surface. B. Abactinal surface detail. C. Lateral view. D. Actinal surface. E. Oral region on actinal surface. Scale bar: A, C–D=2.0 mm; B, E=1.0 mm.