ABSTRACT
In teleosts, the problem of sex determination (Pandian, 2nd volume of this book series) and differentiation (Pandian, 3rd volume) is more puzzling than in any other vertebrates. The following features of sex differentiation are striking examples of teleost’s peculiarity: 1. In both the sexes there are no structural connections between the genital and excretory systems, 2. The somatic tissue of the gonad lacks a dual origin from cortex and medulla, 3. The chromosomes are not differentiated into autosomes and heterosomes and 4. Teleosts are the only vertebrates, among which simultaneous, sequential and serial hermaphrodites are found (Reinboth, 1983).
