Tripneustes gratilla (Linnaeus, 1758)

Fig. 51 A–C.

Tripneustes gratilla: H.L. Clark, 1912: 286, 313–314; H.L. Clark, 1923: 387; H.L. Clark, 1925a: 124 –125; Mortensen, 1943a: 500 –508. Pls. XXXIII. Figs 1–3, Pls. XXXIV. Figs. 2–6, Pls. XXXV. Figs. 3–4, Pls. XXXVII. Figs. 1–2, 4–10, Pls. XXXVIII. Figs. 1–4, Pls LVI. Fig. 11; Clark & Courtman-Stock, 1976: 234; Richmond, 1997: 298; Samyn, 2003: 210, Fig. 4 G; Branch et al., 2010: 234, Fig. 105.5; Schultz, 2010: 275, Figs 527–533.

Material examined. MBC-A 022253; A22254; A23084; MBC-A023324; MBC-A077884; A7015; MBC- A077883.

Identification. Test small, hemispherical with circular outline. Spines short, thin. Denuded test creamish, pores lighter; primary spines variable in color, may be orange, purplish or whitish; secondaries white.

Global maximum size. Maximum test diameter 145 mm.

Global distribution. East and South coasts of South Africa, from central Japan to Australia and from Norfolk Islands to Hawaii; littoral to 75 m (H.L. Clark 1912; Schultz 2010).

Taxonomic notes. T. gratilla differs from Toxopneustes pileolus by its naked, dark median zones and test color.