Body shape variation and colour change during growth in a protogynous fish

Protogynous sequential hermaphroditism isvery common in marine fish. Despite a large numberof studies on various aspects of sequential hermaphroditismin fish, the relationship between body shapeand colour during growth in dichromatic species hasnot been assessed. Using geometric morphometrics,the present study explores the relationship betweengrowth, body shape and colouration in Coris julis (L.1758), a small protogynous labrid species withdistinct colour phases. Results show that body shapechange during growth is independent of change incolour phase, a result which can be explained by thebiology of the species and by the social control of sexchange. Also, during growth the body grows deeperand the head has a steeper profile. It is hypothesizedthat a deeper body and a steeper profile might have afunction in agonistic interactions between terminalphase males and that the marked chromatic differencebetween colour phases allows the lack of strictinterdependence of body shape and colour duringgrowth.