Sexuality in Fishes
Summary
The unprecedented level of diversity recorded among the clones of self-fertilizing gynogenetic unisexuals and self-fertilizing simultaneous hermaphrodites challenges current ideas on the predominant role of recombination in promoting evolution of biological diversity. Though limited to a few species, the existence of self-fertilizing and cyclical sex changing hermaphrodites remians a puzzle to many geneticists and endocrinologists. Within a few days after the removal of a harem master or mistress, a successor changes sex and takes over the harem; the causes for the sex changing mechanism pose many challenges to socio-ecologists and behaviour specialists.This book is a synthesis of relevant and recent information on sexuality of fishes and points towards new directions of desired research.
Table of Contents
Introduction—Life span and sexual maturity; Spawning process; Fecundity; Egg size; Sperm count and sperm cells; Breeding sites; Breeding times; Breeding systems
Sexual pattern
Intersexuality
Gonochorism—Gonadal differentiation; Morphotypes; Sex ratio; Operational sex ratio
Unisexualism—Hybridization; Polyploidization; Poecilia formosa; Menidia clarkhubbsi; Carassius auratus; Cobitis complex; Poeciliopsis monacha—lucida; Phoxinus eos. neogaeus; Rutilus alburnoides
Simultaneous hermaphroditism—Self-fertilizing hermaphrodites; Egg trading hermaphrodites; Potential self-fertilizers
Sequential hermaphroditism
Protogynous hermaphroditism—Transition load; Classification; Pathways and duration of sex change; Sex ratio
Protandric hermaphroditism—Gonadal organization; Sex ratio; Pathways of sex change
Serial hermaphroditism—Marian hermaphroditism; Okinawan hermaphroditism; Serial sex change; Cascade and causes of sex change
Mating systems—Monogamy; Alternate mating strategies; Morphism; Lekking and promiscuity; Parental care
References • Author index • Species index • Subject index
Author Bio(s)
T.J. Pandian: Visiting Professor, CAS Marine Biology, Annamalai University, Tamil Nadu, India
