Members of the phylum Echinodermata are among the most familiar marine invertebrates. Forms such as the sea star have become virtually a symbol of sea life. Used in ancient oriental medicine as a source of bioactive compounds, sea cucumbers, sea stars and sea urchins are now used for the extraction and purification of cytotoxic, haemolytic, antiviral, antifungal, antifouling, antimicrobial and even anti-tumoural activities. In addition, of the five extant classes, sea urchins and sea cucumbers are important economic resources for current fishery and aquaculture. Molecular and cell biological techniques described in this book are, on the one hand, indicative of the improvements made over the years and, on the other, stress the need of their further exploitation for the sustainable production of bioactive compounds and their application in biomedicine.

The proceedings of the Seventh International Echinoderm Conference, held at Atami, Japan, September 1990. In addition to sections covering ecology, evolution, reproduction, morphology, molecular biology, developmental biology, physiology, behavior, and paleontology, there are four plenary lectures a

This book is a compilation of proceedings that contain abstracts of all papers/posters presented at the International Echinoderm Conference held in 1984 and complete papers from those submitted for publication and accepted on the recommendations of referees.

The present title Biology of Echinodermata has been carefully compilated on the basis of all recent researches and investigation made on Echinoderms. It is intended for undergraduate and postgraduate students of all universities. The text material has been written in a very easy, clear, lucid and straight forward manner to make a clear and vivid understanding. All important types have been dealt with complete, authentic and up-to-date account including morphology anatomy, physiology and development of selected types. Efforts have been made to condense the matter as far as practicable. It is hoped that the Biology of Echinodermata will not only meet the requirement of Indian students but will also be useful as a guideline to the teachers and researchers. Contents: Introduction, Asterias, Echinoidea, Holothuroidea, Ophiuroidea, Crinoidea, Influence of Environment, Development of Larva, Water-vascular System in Echinodermata.

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 ( 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.

THE ECHINODERMATA MCQ (MULTIPLE CHOICE QUESTIONS) SERVES AS A VALUABLE RESOURCE FOR INDIVIDUALS AIMING TO DEEPEN THEIR UNDERSTANDING OF VARIOUS COMPETITIVE EXAMS, CLASS TESTS, QUIZ COMPETITIONS, AND SIMILAR ASSESSMENTS. WITH ITS EXTENSIVE COLLECTION OF MCQS, THIS BOOK EMPOWERS YOU TO ASSESS YOUR GRASP OF THE SUBJECT MATTER AND YOUR PROFICIENCY LEVEL. BY ENGAGING WITH THESE MULTIPLE-CHOICE QUESTIONS, YOU CAN IMPROVE YOUR KNOWLEDGE OF THE SUBJECT, IDENTIFY AREAS FOR IMPROVEMENT, AND LAY A SOLID FOUNDATION. DIVE INTO THE ECHINODERMATA MCQ TO EXPAND YOUR ECHINODERMATA KNOWLEDGE AND EXCEL IN QUIZ COMPETITIONS, ACADEMIC STUDIES, OR PROFESSIONAL ENDEAVORS. THE ANSWERS TO THE QUESTIONS ARE PROVIDED AT THE END OF EACH PAGE, MAKING IT EASY FOR PARTICIPANTS TO VERIFY THEIR ANSWERS AND PREPARE EFFECTIVELY.