First estimates of sex allocation patterns and body size-at-sexual maturity and at protogynous sex change are presented for the five major (including one endemic) species of parrotfishes of Hawaii. Median body size at initial maturation as a female (LM50) and at protogynous sex change from adult female to adult male (LΔ50) varied greatly among the five species. Estimates of LM50 were about 14, 17, 24, 34 and 35 cm fork length (LF) in palenose Scarus psittacus, Pacific bullethead Chlorurus spilurus, stareye Calotomus carolinus, spectacled Chlorurus perspicillatus and redlip parrotfish Scarus rubroviolaceus. Values of LΔ50 were c. 23, 27, 37, 46 and 47 cm LF in the respective species. Length at female maturation was proportional to maximum body size (Lmax) of the respective species, ranging from 50 to 72% and averaging 62% of Lmax across species. LΔ50 was also proportional to Lmax, ranging from 82 to 97% and averaging 92%. Males of both pairs of Scarus and Chlorurus spp. reported here are diandric. Only one of the five major species (C. carolinus) is functionally monandric, with either all or nearly all males secondarily derived from adult females. The broadly differing absolute body sizes at sexual maturation and at sex change among the five species have important implications for improving regulatory size limits for parrotfishes in the State of Hawaii, where parrotfish species have historically been managed based on a single minimum size limit of 30·5 cm LF. This study provides a model demonstration of why catch data for parrotfishes, and other size-structured reef-fish populations, should be recorded either by species or by functional size-groups of species that allow setting more meaningful minimum size limits.
Keywords: maturation rates; scarids; scarine labrid; sex allocation.
© 2016 The Fisheries Society of the British Isles.