THE COPEPOD CRUSTACEANS OF CHESAPEAKE BAY 



By Charles Branch Wilson 

 Department of Science, State Normal School, Westfield, Mass. 



INTRODUCTION 



SOUECH OF MATEBIAL 



In 1915-16 and 1920-21 the United States Bureau of Fisheries 

 conducted a biological and hydrographic survey of Chesapeake Bay. 

 During the latter period the survey was under the immediate direc- 

 tion of Dr. K. P. Cowles, of Johns Hopkins University, and the 

 copepods then collected by him were separated from the rest of 

 the plankton and turned over to the author for identification and 

 study.^ 



The material included about one thousand two hundred 2-ounce 

 bottles, with some of larger capacity up to 16 ounces. In sorting 

 and identifying this large quantity of material the author was very 

 ably assisted during the summer of 1923 by his son, John E. Wilson, 

 who separated and counted the species in the various hauls and 

 computed most of the percentages in the accompanying lists. The 

 author identified the species and is entirely responsible for the text of 

 the report. 



COMPABISON WITH OTHEB STUDIES 



Among the numerous plankton studies that have appeared in 

 recent years, especially those more immediately concerned with the 

 free-swimming copepods, there are practically none whose subject 

 material was derived from a source like Chesapeake Bay. The cope- 

 pod fauna of many bays and gulfs has been studied, at times with 

 considerable intensity, as in the case of the Gulf of Naples, Liver- 

 pool Bay, and the Bay of St. Andrews in Europe, and the Gulf of 

 Maine and Narragansett Bay on the North American coast. Such 

 gulfs and bays, however, are little more than partially restricted 

 bodies of salt water, and not enough fresh water enters them to exert 

 an appreciable influence. 



^ The results of the study as a whole have been published by the Bureau of Fisheries 

 as follows : Cowles, R. P., A Fiological Study of the Offshore Waters of Chesapeake Bay, 

 Bull. Bur. Fisheries 46 (Fisheries Doc. 1091), pp. 277-381, 16 flgs., 1930. 



No. 2916.— Proceedings U. S. National Museum. Vol. 80, Art. 15. 



79858—32 1 1 



