ECO-BIOLOGY AND FISHERIES OF THE WHELK, BABYLONIA SPIRATA (LINNAEUS, 1758) AND BABYLONIA ZEYLANICA (BRUGUIERE, 1789) ALONG KERALA COAST, INDIA Thesis submitted to Cochin University of Science and Technology in partial fulfillment of the requirement for the degree of Doctor of Philosophy Under the faculty of Marine Sciences By ANJANA MOHAN (Reg No: 2583) CENTRAL MARINE FISHERIES RESEARCH INSTITUTE Indian Council of Agricultural Research KOCHI 682 018 JUNE 2007 ®edi'catec[ to My Tarents Certificate This is to certify that this thesis entitled “Eco-biology and fisheries of the whelk, Babylonia spirata (Linnaeus, 1758) and Babylonia zeylanica (Bruguiere, 1789) along Kerala coast, India” is an authentic record of research work carried out by Anjana Mohan (Reg.No 2583) under my guidance and supervision in Central Marine Fisheries Research Institute, in partial fulfillment \ of the requirement for the Ph.D degree in Marine science of the Cochin University of Science and Technology and no part of this has previously formed the basis for the award of any degree in any University Dr V ipa (Supervising guide) Sr Scientist, Mariculture Division Central Marine Fisheries Research Institute Date: 3?-95' LN?‘ Declaration I hereby declare that the thesis entitled “Eco-biology and fisheries of the whelk, Babylonia spirata (Linnaeus, 1758) and Babylonia zeylanica (Bruguiere, 1789) along Kerala coast, India” is an authentic record of research work carried out by me under the guidance and supervision of Dr V Kripa, Sr Scientist, Mariculture Division, Central Marine Fisheries Research Institute, in partial fulfillment for the Ph.D degree in Marine science of the Cochin University of Science and Technology and no part thereof has been previously formed the basis for the award of any degree in any University (ANJAN A MOHAN) Date: 2.7» 05- 07 Acknowledgement I am greatly indebted to Dr V Kripa (supervising guide), Sr Scientist, Mariculture Division, Research Center of CMFRI, Calicut for her guidance, valuable suggestions, constant encouragement, criticism and support during the course of my investigation and documentation I owe many thanks to Dr Mohan Joseph Modayil, Director, CMFRI, Kochi for extending all the facilities for successful completion of this research work I express my deep sense of gratitude to Dr K Sunilkumar Mohamed, HOD, Molluscan Division, CMFRI for his constant help, guidance, subjective criticism and encouragement in preparing the thesis It is my pleasure to acknowledge Dr K.K Appukuttan, former HOD anui Principal Scientist, Molluscan Fisheries Division of CMFRI for helping me carry out my work and in the preparation of the manuscript I acknowledge my deepest sense of gratitude to Dr M Srinath, HOD, FRAD, Dr T.S Velayudhan, Principal Scientist, Dr P Laxmilatha, Senior Scientist; Dr Shoji Joseph, Senior Scientist; Dr Somy Kuriakose, Scientist Sr Scale; for their help during the course of my study I am highly indebted to Dr Paul Raj, Scientist­ in Charge, PGPM, CMFRI for the timely help in all matters concerned with my Ph D programme The help and support extended kqriflua PGPM staff':Ms gratefully acknowledged I wish to express my sincere thanks to time OIC library and other staff members" for the help and cooperation extended I am thankful to Dr Sarala Devi, Scientist, Mrs Jasmine, Dr Jayaraj, Research scholars, NIO, Kochi for their help rendered to me during the tenure of work I zmn grateful to [hm P PL Radhakrishnan,