The Indo-Pacific labrid fish genus Stethojulis Günther is represented by the following 10 relatively small, shallow-water species, all of which have a less colorful initial phase that may be male or female and a more colorful terminal-male phase: S. albovittata (Bonnaterre) from the western Indian Ocean, including the Red Sea (S. axillaris is a synonym based on the initial phase); S. balteata (Quoy and Gaimard) from the Hawaiian Islands; S. bandanensis (Bleeker) from the eastern Indian Ocean to islands of the tropical eastern Pacific (S. rubromacula and S. linearis are synonyms based on the terminal-male phase); S. interrupta (Bleeker), widespread in the Indo-Pacific except Hawaii, Japan, Fiji, New Caledonia, and Norfolk Island (S. kalosoma is a synonym based on the initial phase); S. maculata (Schmidt) from Japan, the largest species (to 142 mm standard length); S. marquesensis, n. sp., from the Marquesas Islands; S. notialis, n. sp., from Fiji, New Caledonia, and Norfolk Island; S. strigiventer (Bennett) from East Africa to the Marshall Islands and French Polynesia (S. renardi is a synonym based on the terminal-male phase); S. terina Jordan and Snyder from Japan, Taiwan, and the coast of China south to Hainan (S. trossula is a synonym based on the terminal-male phase); and S. trilineata (Bloch and Schneider) from the Maldives to the Samoa Islands (S. phekadopleura and S. filholi are synonyms base on the initial phase).
The first 3 species listed represent an allopatric complex, all with strongly modal 14 pectoral rays and high number of gill rakers (usually 27-29); the initial phase of all 3 have 2 small dark spots midlaterally on the posterior part of the caudal peduncle. S. marquesensis, also with 14 pectoral rays and modally 27 gill rakers, is distinct in color. S. interrupta, S. maculata, S. notialis, and S. terina are another complex, nearly always with 13 pectoral rays and usually 21-24 gill rakers. S. strigiventer is distinct with a strongly modal pectoral-ray count of 15. S. trilineata, the most colorful of the species, combines a low pectoral-ray count of 13 with a high gill-raker count of 25-28 (modally 27).