The gonadosomatic index, abbreviated as GSI, is the calculation of the gonad mass as a proportion of the total body mass. It is represented by the formula: GSI = [Gonad Weight / Total Tissue Weight] x 100 (Barber & Blake 2006). It is a tool for measuring the sexual maturity of animals in correlation to ovary development and testes development.
References
Gonadosomatic Index Wikipedia(Text) CC BY-SA