Trapezia lutea Castro, 1997

(Fig. 8C, D)

Trapezia lutea Castro, 1997a: 84, figs. 2C, 2D, 3A–C, pls, 2C, 5A.— Castro 1997b: 126; 1999a: 52; 2009: 274, fig. 1D.— Castro et al. 2004: 42 (list).— Liu et al. 2008: 792 (list) (Taiwan Island).— Higashiji 2013: 87, fig. 2E (Ryukyu Islands).— Limviriyakul 2016: 5, fig. 4r (Taiwan Island).— Poupin 2018: 41, fig. 12M (Mayotte Island).

Material examined (Found in Pocillopora ( Pocilloporidae) unless otherwise noted).

Nansha Islands: Mischief Reef, coll. 115°32.5’E 9°55.7’N, 11 m, Shaobo Ma, Yuli Sun, Ziming Yuan, 5 May 2022, 1 male (10.89 × 9.48 mm), NS-MJJ-2022-1056; 1 female (12.30 × 9.90 mm), NS-MJJ-2022-1060; 1 female (11.36 × 8.88 mm), NS-MJJ-2022-1079; 1 male (11.02 × 8.65 mm), NS-MJJ-2022-1080; 1 male (5.20 × 4.17 mm), NS-MJJ-2022-1111; 1 female (5.93 × 4.84 mm), NS-MJJ-2022-1112; 1 male (5.65 × 4.85 mm), NS-MJJ-2022-1113; 115°29.8’E 9°54.4’N, 13 m, coll. Shaobo Ma, Yuli Sun, Ziming Yuan, 6 May 2022, 1 female (4.96 × 4.49 mm), NS- MJJ-2022-1314; 1 male (4.57 × 4.33 mm), NS-MJJ-2022-1315; 1 male (9.34 × 8.37 mm), NS-MJJ-2022-1324; 1 female (8.31 × 7.78 mm), NS-MJJ-2022-1325; 115°31.3’E 9°52.6’N, 8 m, coll. Shaobo Ma, Yuli Sun, Ziming Yuan, 7 May 2022, 1 male (8.15 × 7.07 mm), NS-MJJ-2022-1380, in Seriatopora hystrix ( Pocilloporidae); 115°33.8’E 9°52.9’N, 8 m, 9 May 2022, 1 female (8.65 × 7.29 mm), NS-MJ-2022-1621; 1 pre-adult (3.78 × 3.22 mm), NS- MJ-2022-1622; 115°34.4’E 9°53.5’N, 10 m, coll. Shaobo Ma, Yuli Sun, Ziming Yuan, 10 May 2022, 4 pre-adults (3.89 × 3.36 mm; 3.41 × 3.02 mm; 2.98 × 2.50; 2.79 × 2.65 mm), NS-MJ-2022-1746; 1 pre-adult(2.90 × 2.41 mm), NS-MJ-2022-1748; 2 pre-adults (3.05 × 2.71 mm; 3.34 × 2.95 mm), NS-MJ-2022-1751; 2 pre-adults(4.10 × 3.45 mm; 3.65 × 3.05 mm), NS-MJ-2022-1801; 1 pre-adult (3.66 × 3.21 mm), NS-MJ-2022-1851. Fiery Cross Reef, 112°58.6’E 9°38.7’N, 10 m, coll. Shaobo Ma, Yuli Sun, Ziming Yuan, 12 May 2022, 1 female (6.41 × 5.44 mm), NS-YS-2022-1033; 1 male (4.86 × 4.27 mm),, 3 juveniles (3.01 × 2.39 mm; 3.97 × 3.63 mm; 2.85 × 2.62 mm), NS-YS-2022-1034; 112°58.9’E 9°39.5’N, 3 m, coll. Shaobo Ma, Yuli Sun, Ziming Yuan, 13 May 2022, 1 pre-adult (3.78 × 3.45 mm), NS-YS-2022-1144; 1 male (5.50 × 5.33 mm), 1 female (6.70 × 6.11 mm),, 3 pre-adults (3.65 × 3.33 mm; 3.02 × 2.78 mm; 3.44 × 3.02 mm), NS-YS-2022-1208.— Zhongsha Islands: Walker Shoal, 114°29.0’E 15°55.0’N, 15 m, coll. Shaobo Ma, Yuli Sun, Ziming Yuan, 17 May 2022, 1 male (9.14 × 8.23 mm), 1 female (10.32 × 8.54 mm), ZS-MB-2022-1022; 1 female (8.16 × 6.58 mm), ZS-MB-2022-1054. Shenhu Shoal, 113°0.7’E 19°30.3’N, 17 m, coll. Geng Qin, Wei Jiang, 4 July 2021, 1 male (14.52 × 12.22 mm), ZS2021C9.— Xisha Islands: The Seven Connected Islets, 112°16.2’E 16°58.0’N, 10 m, coll. Shaobo Ma, Yuli Sun, Ziming Yuan, 19 May 2022, 1 male (7.05 × 6.20 mm), 1 female (5.01 × 4.31 mm), 1 pre-adult (3.90 × 3.41 mm), XS-QL-2022-1033; 112°19.6’E 16°57.1’N, 10 m, coll. Shaobo Ma, Yuli Sun, Ziming Yuan, 11 May 2022, 1 female (8.05 × 6.66 mm), XS-QL-2022- 1128, in partially dead Pocillopora ( Pocilloporidae) reef; 1 male (7.89 × 7.01 mm), XS-QL-2022-1169. Zhaoshu Island, 112°16’E 16°59’N, 10 m, coll. Shaobo Ma, 4 June 2021, 1 male (8.08 × 7.10 mm), XSZS.

Geographical distribution. Across Indo–West Pacific region except the Hawaiian Islands (Castro et al. 2004).

Remarks. Trapezia lutea is a relatively common coral symbiont in the South China Sea. The eyes of this species (adult) were noted to be black when they were alive, This characteristic can distinguish T. lutea from T. formosa and T. cymodoce .