Shallow-water Trapezioidea (Decapoda: Brachyura) from the South China Sea, including two new records, and notes on Tetralia glaberrima Herbst, 1790 Author Sun, Yu-Li Qingdao Agricultural University, Qingdao, China. & Laboratory of Marine Organism Taxonomy and Phylogeny, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China. Author Jiang, Wei 0000-0003-4767-8196 Laboratory of Marine Organism Taxonomy and Phylogeny, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China. & Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China. & Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266237, China jiangwei@qdio.ac.cn Author Sha, Zhong-Li Laboratory of Marine Organism Taxonomy and Phylogeny, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China. & Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China. & Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266237, China text Zootaxa 2024 2024-07-04 5476 1 393 423 http://dx.doi.org/10.11646/zootaxa.5476.1.30 journal article 10.11646/zootaxa.5476.1.30 1175-5326 12681889 D5F945AF-65F2-4AB3-AE00-B4C9BC0CE8F3 Tetralia nigrolineata Serène & Pham, 1957 ( Fig. 4C–D , 6E, F ) Tetralia glaberrima f. nigrolineata Serène & Pham, 1957:120 . Tetralia nigrolineata —Galil 1988: 63, figs. 1c, 2e, f.— Castro 1997a: 68 , pl. 1D; 1999a: 41; 1999b: 102; 2009: 277.— Castro et al. 2004: 25 (list).—Machida 2005: 24, fig. 4 (Tosa shimizu).—Castro & Titelius 2008: 321— Ng et al. 2008: 184 (list).— Limviriyakul 2016: 4 , fig. 4k ( Taiwan Island ).— Maenosono 2017: 42 , fig. 8C, D (Ryukyus). Tetralia glaberrima f. obscura Patton, 1966: 287. Tetralia glaberrima obscura Serène, 1984: 283 , pl. 40E. Not Tetralia nigrolineata — Castro 2009: 277 , fig. 2F [= Te. glaberrima Herbst, 1790 ]— Poupin 2018: 37 , fig. 12E [ Tetralia ? nigrolineata = Te. glaberrima Herbst, 1790 ]. Material examined. Hainan Island : Hou Hai , coll. Yuli Sun , 5 May 2023 , 1 female (7.21 × 6.10 mm), VX20230501; 3 m, coll. Yuli Sun , 29 November 2022 , 1 male (11.35 × 10.59 mm), 1 female (13.77 × 12.01 mm), XY1102. Xiaodong Hai , 2–3 m, coll. Lecheng Qu , 5 December 2021 , 1 female (11.21 × 10.07 mm), SY24. Lu hui tou , 3 m, coll. Sirenko , 19 November 2016 , 1 pre-adult (3.27 × 2.96 mm), SY94. Geographical distribution. Across Indo-West Pacific region except the Hawaiian Islands ( Castro et al. 2004 ). Remarks. Tetralia nigrolineata is the largest species of the genus recorded in the South China Sea. A unique specimen ( Fig. 6E , VX20230501) that was collected possess pereiopods that are all white in color. We attempted to explore whether this coloration is of phylogenetic interest, and so we aligned its COI sequence with an individual of normal coloration (SY24) ( Fig. 6F , XY1102). The result, however, suggests that they are conspecific. The phylogenetic tree ( Fig. 11 ) and genetic distance ( Table 3 ) indicate minimal genetic divergence between the individual with a typical brown pattern ( Fig. 6F , XY1102; Fig. 11 , SY24) when compared to the specimen with white pereiopods ( Fig. 6E ; Fig. 11 , VX20230501).