Both male and female of T. zillii and T. rendalli undergo coloration changes of similar intensity. In the genus Sarotherodon, for example S. galilaeus where both parents orally rear eggs, the differences in colour and their intensity is minimal whereas in Oreochromis, for example O. niloticus, O. aureus and O. mossambicus, there is a marked sexual difference between males and females. The breeding coloration of some commercially important species is given in Table 10.3.