EXPERIMENTAL STUDY OF THE FUNCTION OF THE OYSTER 

 GILLS AND ITS BEARING ON THE PROBLEMS OF OYSTER 

 CULTURE AND SANITARY CONTROL OF THE OYSTER 

 INDUSTRY 



By PAUL S. GALTSOFF, Ph. D. 

 Aquatic biologist, United States Bureau of Fisheries 



CONTENTS 



Introduction 



Structure of the oyster gills 



Review of the methods for measuring the 

 strength of current produced by plank- 

 ton-feeding organisms 



Indirect methods 



Direct methods 



Methods employed in the present investi- 

 gation ^ 



Tank method 



, .Carmine method 



Face 

 1 



8 



8 



10 



10 

 10 



11 



Effect of temperature on the rate of flow 



of water through the gills .. 



Summer e.xperiments - ,. _l.iw_ 



E.\]ieriments with hibernating oys- 

 ters 



Temperature at which the ciliary motion 



ceases completely 



Straining of water b_v the gills 



Opening and closing of the shell 



Discussion and conclusions 



Resume -- 



Bibliography 



Pass 



15 

 15 



21 



24 

 27 

 28 

 34 

 35 

 36 



INTRODUCTION 



A study of the physiology of the oyster is of great practical importance for the 

 oyster industry and at the same time it presents a broad and interesting field for 

 research that hardly has been touched by scientific investigation. The present paper 

 deals with the function of the gills of the American oyster. 



The gill may be regarded as one of the most conspicuous of the organs that take 

 part in the feeding and respiration of the oyster. The fact that great quantities 

 of oysters are consumed raw makes the questions of what constitutes the food of an 

 oyster and how it is taken in of great practical unportance. Because the mode of 

 feeding consists in straining great volumes of water through the gills and mgesting 

 the microscopical material suspended therein, the purity of the oyster meat is corre- 

 lated closely with the character of the water runnmg over the oyster beds. 

  ; It has been known for many years that the general appearance of the oyster, 

 the thickness and shape of its shell, and the quality and flavor of its meat reflect 

 readily the conditions of the environment under which the organism grew. The 

 constantly increasing pollution of our inshore waters caused by the discharge of 

 domestic sewage and trade wastes has ruined many thousands of acres of profitable 

 oyster grounds and in many instances has rendered the oysters grown m the vicinity 

 of large cities unfit for human consumption. Long before the discovery of bacteria 



1 



