Monachaster sanderi (Meissner 1892)

Figure 25 A–D

Meissner 1892: 185; Ludwig 1899: 539 (as Goniodiscus)

Döderlein 1916: 412; 1935: 103; Clark & Rowe 1971; 48; Tortonese 1976: 272; 1980: 113; Walenkamp 1990: 32; Gosliner et al. 1996: 256 (as Monachaster sanderi)

Macan 1938: 399; Tortonese 1949: 31(as Monachaster umbonatus)

Diagnosis. Body weakly stellate to stellate (R/r=1.6–1.8) (Fig. 25A). Abactinal, marginal, actinal surface covered by low, closely distributed granules. Abactinal regions variably with large, conical tubercles along radial regions. Superomarginals with large, quadrate bald patches (Fig. 25B). Furrow spines four or five in straight series (Fig. 25D). Subambulacral variably present or absent. Adambulacral pedicellariae present or absent.

Comments. Monachaster sanderi represents one of the most frequently encountered asteroids from the western Indian Ocean region. Morphological variation was explored by Tortonese (1976) and Walenkamp (1990). There is also abundant representation of this species in the MNHN collections, primarily from Madagascar.

Walenkamp (1990) described this species color in life as a dark reddish brown. Gosliner et al. (1996) provided a living image from Madagascar showing it to be an overall light lavender color with a dark purple occupying the bare, convex central portion on the superomarginal plates and on plates forming the primary circlet.

Occurrence. Mozambique ( Inhaca Island), Madagascar, Tanzania, Somalia, Red Sea to the Gulf of Suez, 2–68 m.

Material Examined. IE-2007-5123 Madagascar, 25° 12.6 'S, 44° 8.6' E, 13–27 m. Coll . ATIMO VATAE TA 21, JS-195. 1 wet spec. R=~5.0, r=~3.0