Advances in MARINE BIOLOGY VOLUME 12 This Page Intentionally Left Blank Advances in MARINE BIOLOGY VOLUME 12 Edited by SIR FREDERICK S. RUSSELL Plymouth, England and SIR MAURICE YONGE Edinburgh, Scotland ACADEMIC PRESS, INC. (Harcourt Brace Jovanovich. Publishers) London Orlando San Diego New York Toronto Montreal Sydney Tokyo ACADEMIC PRESS INC. (LONDON) 24-28 Lm. OVAL ROAD LONDON N W 1 7 D X U.S. Edition published by ACADEMIC PRESS, INC. Orlando, Florida 32887 NEW YORK, NEW YORK 10003 Copyright 0 1974 by Academic Press Inc. (London) Ltd. All rights reserved NO PART OF THIS BOOK MAY BE REPHODUCED IN ANY FORM BY PHOTOSTAT, MICROFILM, OR ANY OTHER MEANS, WITHOUT WHITTEN PEHMISSION FROM THE PUBLISHERS Library of Congress Catalog Curd Number: 63-14040 ISBN: 0-12-026112-X PRINTEDINTHEUNITEDSTATESOFAMERICA 85 86 87 88 9 8 1 6 5 4 3 2 CONTRIBUTORS TO VOLUME I2 TLIONEL E. MAwnESLEY -'rHOMAR, jiuntinydon h w a r c h Centre, Hunt ingdon , England. MAKOTOOMORC, Ocean Research Institute, (Jniverdy of Tokyo, Nnkano, Tokyo, Japan. ALAIN SOURNIA, Laboratoire des Pgches Outre-mer, Muse'um national d'Histoire naturelle, 57 rue Cuvier, 75231 Park8 Cddex 05, France. tDr Mewdesley-Thomasdied on 30 August 1974. This Page Intentionally Left Blank CONTENTS . I The Physiology of Ascidians IVAN Goon~onv T. 11. Introduction .. The Ascidian Test 111. The Branchia1,Sac IV. The Endostyle V. lodine Binding VI. VIT. VII 1. .. .. .. .. .. .. .. .. .. 2 *. .. 3 .. .. .. ,. .. .. .. .. .. .. .. .. .. .. .. .. .. The Alimentary System .. A. Food Transport .. €3. Histology of the Alimentary Canal C. Digestion . . .. .. .. I). The Pyloric Gland .. .. .. 'l'hc Circu1iLtor.y Systrrrl .. A. Structure of the Heart . . 13. ('ontraction d t h v Heiwt . . (1. Pacemaker Activity .. Respirution 9 . .. .. I). Cardio-regulatoryDrug8 E. Conduction .. I?. Heitrt Beat Reversid (2. Conclusion . . .. IX. .. *. Ascitlian Blood . . A. The Plasma B. Blood Cells. . .. .. .. .. .. .. .. .. .. .. vii .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. * . *. I . .. .. a . .. .. .. .. .. .. 16 23 27 30 30 .. 31 .. 35 .. 39 .. .. .. . .. .. .. .. .. .. .. .. 43 , 44 45 48 50 62 54 57 62 04 64 67 ... CONTENTS Vlll X. XT. (:. Heavy Metals in Ascidian Blood 1). Agglutination .. .. .. E. Blood Function . . .. * . .. .. .. .. .. Nitrogen Excretion .. . I The Nervous System .. .. A. 8tructure of the Nervous System B. The Visceral Innervation .. C. The 8ensory System .. .. 1). Photoreception .. . . .. E. The Somatic Motor System .. F. Synaptic Transmission . . .. G. Neurosecretion . . .. . . XI[. T h e Neural Gland.. .. .. A. Structure and Clyolic Activity R. Origin of t h e Neural Gland C. Functions of the Neural Gland XIII. The Dorsal Strand XIV. Conclusion .. .. <