Expression of sox9a , dmrt1 , ar , cyp19a1b , fig α and cyp19a1a in individual juvenile zebrafish during the investigated period from 2–40 dph. On each sampling date 12 individuals were investigated. The cut-off value between high and low expressers is indicated on each of the figures by the segmented Y-axis. The expression pattern of ar, sox9a, dmrt1, fig α and cyp19a1a were compared in each individual zebrafish, three genes with expected high expression in males (ar, sox9a, dmrt1) and two genes with expected high expression in females (fig α, cyp19a1a). Individuals with expression pattern of all five genes that were as expected for either male or female corresponded to 56% and symbols ■ were used for the tentative identification of males and ▲ were used for the tentative identification of females. Individuals in which the expression of all five genes was not as expected for either female or male corresponded to 44% and were called intermediate ●. cyp19a1b was not included in the tentative identification of sex (see text for explanation) and therefore the ● symbol was used.