istw VO.VIC 



ARCTIC COPEPODA IN PASSAMAQUODDY BAY. 



By a. Willey (McGill University, Montreal). 

 Presented by Samuel Henshaw. 



Received November 9, 1920. Presented January 11, 1921. 



The effect of the heavy tides in the Bay of Fundy upon the dis- 

 tribution of fishes in that region has been discussed by Dr. A. G. 

 Huntsman (1918). He found that certain species of migratory fishes, 

 whilst not being excluded from the Bay of Fund}^, are unable to breed 

 there successfully. All divisions of the marine fauna will naturally 

 be exposed to the same infiuence and it only remains to follow up the 

 question with reference to other orders. More than one circumstance 

 lends interest to the investigation. Through the work of the Bio- 

 logical Stations at Woods Hole, Mass., a very complete knowledge 

 has been obtained of the fauna of the Vineyard Sound Region to the 

 south of Cape Cod which marks the position of the "Great Divide" 

 between the boreal and temperate zones on the Atlantic coast of 

 America. We have therefore an excellent standard of comparison 

 at our disposal, and I have considered it worth while to emphasize 

 the Arctic elements in our local marine fauna. 



For some years, under the direction of Dr. Huntsman, plankton 

 gatherings have been taken methodically at stations situated in and 

 around Passamaquoddy Bay, in addition to outlying stations farther 

 afield in the Gulf of St. LawTence. Of these stations, one known as 

 "Prince" Station 6 lies a little above the actual mouth of the St. 

 Croix River, in the deep channel between the Biological Station near 

 St. Andrews, N. B., and the settlement of Robbinston on the coast 

 of Maine. In 1916-17, the plankton at this station showed excep- 

 tional features, particularly in the winter months, when there was a 

 great demonstration of red oily Cahums constituting what I have 

 elsewhere named a red macrocalanoid plankton. The result of the 

 examination of this plankton, to which my attention was drawn by 

 Dr. Huntsman, is the subject of the present note. In 1919-20 there 

 was no such indraught of large calanoids, the winter plankton being 

 sparse and microcalanoid. 

 _ The four species whose presence gives a special significance to the 

 ^ material comprise the largest of the free-living Copepods, namely, 

 -— Calanus finmarchicus, Calanus hyperboreus, Euchaeta norvegica, and 

 I 

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