Anatomy of finfish and shellfish

Unit 8 - Urino – Genital System

8.2. Reproduction
The reproduction in fishes is bisexual, hermaphrodite or parthenogenic the most predominate process is bisexual reproduction. In such fishes the sexes are separate. Eg :- The individuals are dioecious. In few fishes both sexes are present in same individuals i.e., such fishes are hermaphrodite. Eg. Perca, Stizortadian, Micropterus. In some fishes, juvenile hermaphroditism has been noticed. In Poecillia fermosa parthenogenesis occurs, actually the correct process is gynogenesis i.e., the development of young without fertilization.
Members belonging to class Pisces show a variety of sexuality from synchronous hermaphroditism, protogynous and protandrous hermaphroditism (consecutive hermophroditism) to gonochorism (Dioecious).
Types of Reproduction:
Synchronus hermaphroditism :
In synchronus hemophroditism, both testis and ovary mature at the same time with a possibility of self fertilization. Eg. Scrranus subligirus
Family – Serranidae, Cyprinadontidae, Maenidae, Labridae, Ipoopidae etc.
Consecutive hermaphroditism:
In Consecutive hermaphroditism the fish may be first a female with functional ovaries and consequently a functional male, such hermaphroditism is called “Protogynous hermaphroditism” and when the fish first a functional male and then a functional female such hermaphroditism is term “Protandrous hermaphroditism”.
Protandrous - Gonostamatidae, Sparidae, Labridae.
Protogynous – Synbranchidae, Serranidae, Maenidae.
Gonochorism (Dioecious):
Gonochorism means when both the sexes, male and female are two separate functional individuals (unisexual the male and female reproductive organs born on different individuals).