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)

Carapace morphology. A, C, E, G Tubuca alcocki sp. n., B, D, F, H T. urvillei (H. Milne Edwards, 1852). A holotype male (CW 30.1 mm, ZRC 2017.1278; Thailand) B male (CW 34.9 mm, NCHUZOOL 14895; Kenya) C male (CW 29.5 mm, NCHUZOOL 14896; Ranong, Thailand) D male (CW 29.7 mm, ZRC 1999.1107; Mayotte) E male (CW 27.8 mm, NCHUZOOL 14905; Thailand) F male (CW 27.9 mm, NCHUZOOL 14895; Kenya) G female (CW 22.6 mm, NCHUZOOL 14900; India) H female (CW 22.9 mm, SMF 19985; Kenya).