Sexuality in Fishes

About this book

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 remains 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.

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

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Biography

T.J. Pandian: Visiting Professor, CAS Marine Biology, Annamalai University, Tamil Nadu, India