Tubuca alcocki, a new pseudocryptic species of fiddler crab from the Indian Ocean, sister to the southeastern African T. urvillei (H. Milne Edwards, 1852) (Crustacea, Decapoda, Brachyura, Ocypodidae)

Tubuca alcocki sp. n. A–G variation of the live colouration. A, B holotype (CW 30.1 mm, ZRC 2017.1278; Thailand) C adult male (not collected; Phuket, Thailand) D young male (CW 13.0 mm, NCHUZOOL 14897; Thailand) E ovigerous female (CW 19.8 mm, NCHUZOOL 14897, Thailand) F, G females in the field (not captured; Phuket, Thailand) H habitat in Ranong, Thailand.