Abstract
Coloration and sex change were studied in a temperate wrasse Halichoeres poecilopterus in the central part of the Seto Inland Sea, Japan. 1, 270 examples, 45-179mm SL, were collected from May to December both in 1983 and 1984. The species is a diandric, protogynous hermaphrodite, and has three color patterns: pale color type (A), brilliant color type (B) and intermediate color type (AB). A-fish were less than 142mm SL and consisted of primary males (42.6%), females (55.4%), secondary males (0.3%) and fish with transitional gonads (1.7%). A-females changed their color to B, through AB, in the size range 101-131mm SL. A-primary males changed their color to B, through AB, in the size range 103-134mm SL. B-fish consisted of primary males (38.6%), secondary males (54.6%) and fish with transitional gonads (6.8%). The majority of females changed their sex to male in the size range 98-131mm SL.
