000			04242cam a2200397Ii 4500
001			9780815364733
008			180706s2018 xx a o 000 0 eng d
020			_a9780815364733 _q(e-book : PDF)
020			_a9781351106900 _q(e-book: Mobi)
020			_z9780815364726 _q(hardback)
024	7		_a10.1201/9780815364733 _2doi
035			_a(OCoLC)1022760274
040			_aFlBoTFG _cFlBoTFG _erda
072		7	_aNAT001000 _2bisacsh
072		7	_aSCI039000 _2bisacsh
072		7	_aSCI072000 _2bisacsh
100	1		_aPandian, T. J., _eauthor. _912666
245	1	0	_aReproduction and Development in Echinodermata and Prochordata
250			_aFirst edition.
264		1	_aBoca Raton, FL : _bCRC Press, _c2018.
300			_a1 online resource
336			_atext _2rdacontent
337			_acomputer _2rdamedia
338			_aonline resource _2rdacarrier
490	0		_aReproduction and Development in Aquatic Invertebrates
505	0	0	_tchapter 1 Introduction / _r T. J. Pandian -- _tchapter 2 Fisheries and Aquaculture / _r T. J. Pandian -- _tchapter 3 Sexual Reproduction / _r T. J. Pandian -- _tchapter 4 Asexual Reproduction / _r T. J. Pandian -- _tchapter 5 Regeneration / _r T. J. Pandian -- _tchapter 6 Sex Determination / _r T. J. Pandian -- _tchapter 7 Sex Differentiation / _r T. J. Pandian -- _tchapter 8 Reproductive Biology / _r T. J. Pandian -- _tsection I Non-Chordate-Deuterostomia -- _tSection Ia: Echinodermata -- _tchapter 9 Cephalochordata / _r T. J. Pandian -- _tchapter 10 Urochordata / _r T. J. Pandian -- _tchapter 11 New Findings and Highlights / _r T. J. Pandian -- _tsection II Chordate Deuterostomia.
520	2		_a"Echinoderms and prochordates occupy a key position in vertebrate evolution. The genomes of sea urchin share 70% homology with humans. Researches on cell cycle in sea urchin and phagocytosis in asteroids have fetched Nobel Prizes. In this context, this book assumes immense importance. Echinoderms are unique, as their symmetry is bilateral in larvae but pentamerous radial in adults. The latter has eliminated the development of an anterior head and bilateral appendages. Further, the obligate need to face the substratum for locomotion and acquisition of food has eliminated their planktonic and nektonic existence. Egg size, a decisive factor in recruitment, increases with decreasing depths up to 2,000-5,000 m in lecithotrophic asteroids and ophiuroids but remains constant in their planktotrophics. Smaller (< 18 mm) ophiuroids do not produce a lecithotrophic eggs but larger (> 110 mm) asteroids generate planktotrophic eggs only. Publications on sex ratio of echinoderms indicate the genetic determination of sex at fertilization but those on hybridization, karyotype and ploidy induction do not provide evidence for heterogametism. But the herbivorous echinoids and larvacea with their gonads harboring both germ cells and Nutritive Phagocytes (NPs) have economized the transportation and hormonal costs on gonadal function. Despite the amazing potential just 2 and 3% of echinoderms undergo clonal reproduction and regeneration, respectively. Fission is triggered, when adequate reserve nutrients are accumulated. It is the most prevalent mode of clonal reproduction in holothuroids, asteroids and ophiuroids. However, budding is a more prevalent mode of clonal reproduction in colonial hemichordates and urochordates. In echinoderms, fission and budding eliminate each other. Similarly, autoregulation of early development eliminates clonal reproduction in echinoids and solitary urochordates. In pterobranchs, thaliaceans and ascidians, the repeated and rapid budding leads to colonial formation. Coloniality imposes reductions in species number and body size, generation time and life span, gonad number and fecundity as well as switching from gonochorism to simultaneous hermaphorditism and oviparity to ovoviviparity/viviparity."--Provided by publisher.
650	0	4	_aBIOSCIENCEnetBASE _912667
650	0	4	_aLIFESCIENCEnetBASE _912668
650	0	4	_aOceanography _912669
650	0	4	_aSCI-TECHnetBASE _912670
650	0	4	_aSTMnetBASE _912671
776	0	8	_iPrint version: _z9780815364726
856	4	0	_uhttps://www.taylorfrancis.com/books/9780815364733 _zClick here to view.
942			_cEBK
999			_c70272 _d70272