- --~ SH ICLARM Studies and Reviews 21 207 SR76 #C~I .The Biology and Culture of Pearl Oysters .,. (Bivalvia: Pteriidae) M.H. GERVIS and N.A. SIMS a ~ CDA II c![)lb~fRlM OVERSEAS DEVELOPMENT ADMINISTRATION (ODA) INTERNATIONAL CENTER FOR LIVING AQUATIC OF THE UNITED KINGDOM RESOURCES MANAGEMENT LONDON, ENGLAND MANILA, PHILIPPINES iIII ~he;fjiolog~and Culture of Pearl Oysters (Bivalvia: Pteriidae) M.H. GERVIS and N.A. SlMS IDA OVERSEAS DEVELOPMENT ADMINISTRATION (ODA) INTERNATIONAL CENTER FOR LIVING AQUATIC OF THE UNITED KINGDOM RESOURCES MANAGEMENT LONDON, ENGLAND MANILA, PHILIPPINES LA,Tb' ,- --1 --C ,4!>.,, </C 5: ; The Biology and Culture L" - , of Pearl Oysters & ,:< (Bivalvia: Pteriidae) ,?, !, NOV : 2 1s~ M.H. GERV~SAND N.A. SIMS Printed in Manila, Philippines Published by the Overseas Development Administration 94 Victoria Street, Cnndon SWlE SJL, United Kingdom and the International Center for Living Aquatic Resources Management, MC P.O. Box 1501, Makati, Metro Manila, Philippines. ICLARM's Technical Series were developed in response to the lack oC existing publishing outlets Cor loner papera on tropical fisheries research. The ICLARM Studies and Reviews series consists of concisc documents providing thorough coverage oC topics of intcrcst to the Center, which are undertaken by staff or by external specialists on commission. Essentially, all documents in the series are carefully peer reviewed externally and intcmally. A number havc bcen rcjcctcd. Those published are thus primary literature. Between 1,000 and 2,000 copies of each title are disseminated - sold or provided in exchangt: or free of charge. Gervis, M.H. and N.A. Sims. 1992. The biology and culture of pearl oysters (Bivalvia: Pteriidae). ICLARM Stud. Rev. 21, 49 p. ISSN 011 5-4389 ISBN 971-8709-27-4 Cover: Top: Ago Bay, Japan - Home of pearl culture. (Photo by M. Gervis). Bottom, left: P. margaritifera being harvested from spat collectors in the Cook Islands. (Photo by N. Sims). Bottom, right: P. margaritifera suspended on a longline by the ear hanging technique. (Photo by N. Sims). ICLARM Contribution No. 837 CONTENTS ABSTRACT ...........................................................................................................v INTRODUCTION History of Pearls and Pearl Culture ...............................................................1 TAXONOMY AND DISTRIBUTION Taxonomy ........................................................................................................3 Species Descriptions ........................................................................................4 Pinctada maxima .................................................................................4 Pinctada margaritifera .............................................................................5 Pinctada fucata .........................................................................................5 Pteria penguin ........................................................................................... 5 Distribution .................................................................................................5 Species Introductions ......................................................................................8 ECOLOGY AND BIOLOGY Anatomy ..........................................................................................................9 Shell .......................................................................................................... 9 Foot and byssal gland .............................................................................10 Environmental Factors .................................................................................. 10 Temperature .............................................................................................10 Depth ........................................................................................................11 Salinity .....................................................................................................11 Substrate and silt load ............................................................................12 Currents ................................................................................................. 12 Pollution .................................................................................................. 12 Food and Feeding ..........................................................................................-13 Reproduction .................................................................................................. 13 Sexuality ..............................................................................................13 Maturity ...................................................................................................13 Gonad development ..................................................................................14 Spawning seasonality .............................................................................. 15 Spawning process .................................................................................... 15 Larval development ..................................................................................15 Growth ...........................................................................................................16 Shell dimensions ......................................................................................17 Dorsoventral measurement (DVM) ...................................................17 Anteroposterior measurement (APM) ...............................................17 Hinge length ...................................................................................... 17 Heel depth .........................................................................................18 Thickness and hinge width ................................................................18 Weight ......................................................................................................18 Morphometrics .........................................................................................18 Growth rates ............................................................................................18 Factors affecting growth ..........................................................................19 Mortality ........................................................................................................19 Predation ................................................................................................. 19 Fouling and boring ..................................................................................20 Parasites and pathogens .........................................................................21 CULTURE: OF PEARL OYSTERS Hatchery Culture ...........................................................................................22 Spawning ................................................................................................. 22 Larval rearing .........................................................................................23 Larval feeding ......................................................................................23 Aspects of Pearl Oyster Culture (Photo Section) ................ 24-25 Settlement ................................................................................................ 26 Genetics and Hatchery Production ...............................................................27 Spat Collecti.on ............................................................................................... 27 Nursery Rearing ............................................................................................29 Ongrowing .....................................................................................................30 Rafts .........................................................................................................31 Longlines and fencelines .................. .................................................... 32 Trestles .................................................................................................. 34 Fouling Control ..............................................................................................34 Pearl Culture .................................................................................................34 Preoperative phase ................................................................................... 35 Spherical pearl implant operation .........................................................35 Pearl formation .................................................................................... 37 Postoperative care ....................................................................................37 Pearl culture period .................................................................................37 Harvesting ............................................................................................37 Half pearl production ..............................................................................38 MARIZETING AND ECONOMICS ......................................................................39 CONCLUSIONS ....................................................................................................41 ACKNOWLEDGMENTS ....................................................................................... 41 REFERENCES ...................................................................................................... 42 The Biology and Culture of Pearl