* Tetrapygus niger (Molina, 1782)

Fig. 35 A–C.

Tetrapygus niger: H.L. Clark, 1925a: 17; Branch et al., 2010: 236, Fig. 106.3; Haupt et al., 2010; Schultz, 2010: 128, Figs 233– 235; Filander & Griffiths, 2014: 52. Pl. I, Fig. J.

Material examined. A28054.

Identification. Cleaned test white with dark pore zones, apical disc black, interambulacra median zone purplish, tubercles head violet. Color in life black to dark purple, fairly short spines, longest around the equator.

Global maximum size. Maximum test diameter 75 mm.

Global distribution. West Coast of South America in Peru and Chile, littoral to 10 m (Schultz 2010). Introduced to West coast region of South Africa.

Remarks. Accidentally introduced with oyster spat, first recorded in South Africa in 2007 (Branch et al. 2010; Haupt et al. 2010). Reported only from a single on-land oyster farm, which is no longer operational, so local population may no longer exist (Filander & Griffiths 2014; Mabi et al. 2015).