Morphology and Attached Stages of First Gopepodid 

 Larva of Salmincola edwardsii (Olsson) Wilson 



Nathan Fasten 

 University of Washington, Seattle 



CONTENTS 



1. Introduction 153 



2. Historical 154 



3. Morphology of first copopodid larva 154 



A. External anatomy 154 



B. Internal anatomy 155 



a. Eye 155 



b. Attachment filament 156 



c. Glands 156 



d. Muscular system 157 



e. Digestive system 157 



f. Nervous system 159 



g. Reproductive system 159 



4. Attachment stages of the copepod 159 



5. Summary 163 



6. Bibliography 164 



1. INTRODUCTION 



Although considerable has been written about the parasitic copepods 

 of the family Lernaeopodidae, yet there is a vpoful lack of accurate in- 

 formation regarding them. Many of the generalizations concerning the 

 family are, by some, based upon results obtained from the study of a single 

 species, or from analogy with species of other families of copepods. For 

 a number of years (1912-1918) the writer has been studying the parasitic 

 copepod Salmincola edwardsii (Olsson) Wilson, one of the Lernaeopodidae, 

 which attacks the brook-trout Salvelinus fontinalis Mitchill. The pur- 

 pose of the present contribution is: (1), to clear up certain points regard- 

 ing the morphology of the first copepodid larva of the species; (2), to 

 present more accurate information concerning the attachment of the para- 

 site to the host. For this work the author had an abundance of material 

 on hand, which was obtained in the various trout hatcheries of the state 

 of Wisconsin. This material was prepared according to the methods al- 

 ready outlined in his previous publications of 1914 and 1916. 



(153) 



