THE SPAWNING HABITS OF THE SEA LAMPREY, 

 PETROMYZON MARINUS 1 



DR. L. HUSSAKOF 

 American Museum of Natural History 



The spawning habits of several species of lamprey are 

 known from observations which have been made in both 

 Europe and America. 2 Those of the sea lamprey, Petro- 

 myzon marinus, however, have not been studied, not- 

 withstanding that this is the largest of the lampreys and 

 is common to both sides of the Atlantic. It is merely 

 known that this species ascends rivers for the purpose of 

 spawning; and that the "fish" transport stones in build- 

 ing their nest much like other lampreys (Burroughs, 

 '83; Holder, '85). In 1883 a French observer, L. Ferry 

 ('83), noted the development of sea lamprey eggs taken 

 directly from a female specimen. He concluded that the 

 eggs must already have been fertilized, and hence that 

 fertilization in the lampreys is internal. This conclusion, 

 in the light of the careful observations on the spawning 

 of various lampreys, especially Petromyzon planeri and 

 Lampetra ivilderi, is undoubtedly erroneous. Moreover, 

 the discovery that lamprey eggs can develop partheno- 

 genetically (Bataillon, '03), affords a simple explana- 

 tion of the facts recorded by Ferry. None the less the 

 observation of the breeding habits of the sea lamprey 

 was very desirable. 



The observations recorded in this paper were made by 

 the writer on Long Island, June 1 and 2, 1911, while col- 

 lecting material for a group to represent the nesting 

 habits of the sea lamprey in the American Museum of 

 Natural History. The locality, Smithtown, on the Nis- 

 sequogue River, Long Island, was suggested to me by 



^ead before the American Society of Zoologists, at Princeton, N. J., 

 Dec. 27, 1911. 



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