Gonadal steroid hormone patterns in saddleback wrasses are paralleled by differences in gonadal ultrastructure and steroid hormone synthetic capacity. Females exhibited greater gonadal E2 synthetic capacity than advanced sex changers in vitro when stimulated by salmon gonadotropin, while terminal phase males showed greater 11KT synthesis than females in vitro with advanced sex changers being intermediate . A follow up study compared terminal phase males with female-mimic initial phase males . Initial phase males are externally indistinguishable from females except for the genital papilla. This external similarity is likely important for success in ‘sneaker’ mating tactics (a topic I return to in section 3). Continue reading “Gonadal steroid hormonal patterns revealed for other sex modifying kinds are essentially in keeping with those for saddleback wrasses”