Pandian T.J. (ed.) Sex Determination in Fish

CRC Press, 2012. — 290 p. — ISBN13: 978-1-4398-7919-1 (eBook - PDF)Fishes are indeed the most versatile and fascinating group of animals; in them sex, sexuality, simple and multiple sex chromosome systems and sex determining genes remain an elusive evolutionary enigma. In fact no other group of animals offers as much scope as fi shes do for the study and research on sex determination.With most divergent expression of sex including many morphotypes within a sex, sexuality ranges from gonochorism to unisexualism and to an array of almost unbelievable patterns of functional hermaphroditism and reproductive modes from sexual to gynogenesis and to hybridogenesis, each involving oviparity to viviparity. The title of the book is a ‘hot area’ of research. Not surprisingly, there are many reviews and books on this topic. However, these are more concerned with sex differentiation than sex determination; they have not considered unisexualism in the context of sex determination in fi shes. In an attempt to fi nd clues to resolve the riddle of sex determination in fi shes, this comprehensive book explores it from cytogenetics through hybrids, gynogenics, androgenics, ploidies, allogenics/xenogenics to sexonomics of gonochores, hermaphrodites and unisexuals. About 77 and 50% of references cited here are dated after 1991 and 2001, respectively; they were collected from widely scattered 375 sources of journals, book proceedings, theses and so on. As the book is a continuum of the earlier book ‘Sexuality in Fishes’, there are a few unavoidable but obligatorily required duplications to keep each chapter complete and independent, besides pointing out areas of research requiring critical inputs. None of the earlier reviews/books have ever considered allogenics/xenogenics; this book is the fi rst to report that researches in this frontier area have conclusively shown that fi shes have retained bisexual potency even after sexual maturity and spermiation. The XY genotype found in the unexpected female phenotypes sired by supermales (Y1Y2) and androgenic males (Y2Y2) points out the need to employ sex specifi c molecular markers to identify the true genotype of a juvenile, which matures either as a male or female, depending upon the sex of its pair (female or male) and thereby critically assess the environmental role in sex determination. Hopefully, this book bridges the gaps among molecular biologists in search of sex determining gene(s), fi shery biologists endeavouring to develop techniques for profi table monosex aquaculture and ecologists interested in conservation of fi shes and their genomes. This book is the second in this series brought out by Science Publishers.