CANADIAN FISHERIES EXPEDITION, 191J,-io 405 



CANADIAN FISHERIES EXPEDITION, 1914-1915. 



BIOLOGY OF ATLANTIC WATERS OF CANADA. 



SOME QUANTITATIVE AND QUALITATIVE PLANKTON STUDIES OF THE 

 EASTERN CANADIAN PLANKTON. 



BY 



A. G. HUNTSMAN, B.A., M.B., Etc., 



University of Toronto, Curator of the Atlantic Biological Station, St. Andrews, 



New Brunswick. 



1 . — Introduction. 

 2. — Quantity of Plankton. 



S. — A special Study of the Canadian Chaetognaths, their distribution, et<:-., in the 

 'waters of the Eastern Coast. 



PREFATORY NOTE. 



By Prof. E. E. Prince^ Dominion Commissioner of Fisheries, and Chairman of the 



Biological Board of Canada. 



A note of explanation api>ears desirable respecting the series of papers by Dr. 

 Huntsman which are here brought together. They are separate reports upon his work 

 during the season of 1915 (under Dr. Hjort's Canadian Fisheries Expedition) ; but, in 

 subject and treatment, they form practically one research, the first short paper being of 

 the nature of an introduction ; the second paper has a general character, the quantitative 

 phase being emphasized in it, and demonstrating that in colder and deeper water the 

 plankton content is more abundant than in warmer, more superficial, strata, while the 

 plankton as a whole seeks during the night a deeper level than during the day. The 

 third paper embodies a detailed study of the distribution of Sagitta, or rather of the 

 Chaetognaths, of which Dr. Huntsman determines ten species in our eastern coastal 

 waters, seven species of Sagitta, and one species each of Pterosagitta, Eul-rohnia, and 

 Khronitta. These delicate, actively swimming creatures, of a glassy translucency and 

 needlelike in form, are typical pelagic forms, at one time included amongst sea-worms; 

 but now^ regarded as an aberrant group. They proved to be very abundant, and must 

 form an important element of food for fishes, especially in the younger stages of the 

 latter. These Chaetognaths vary in length from half an inch to tmo inches (50mm.) in 

 length, and Dr. Huntsman's elaborate study is of special interest and importance, and 

 illustrated by twelve figures, four of them being drawings of the creatures themselves, 

 and eight of them charts showing the details of their distribution in the sea. 



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