180 Conservation Department 



(Entosphemis) of the Pacific Coast are parasitic, and some of 

 them, found in the Columbia river and its tributaries, grow to a 

 size almost equal to that of the sea lamprey of the Atlantic. 



This change from a predatory life must be very recent, geologic- 

 ally speaking, for the animal has all the machinery for parasitism ; 

 even the buccal glands with their anticoagulating secretion still 

 persist. The piston-like tongue and the sucking mouth are still 

 useful for nest building and mating, but the horny teeth of the 

 disc and the sharp rake-like teeth of the tongue seem wholly un- 

 called for. Indeed, as shown by Dr. Reighard and his pupils, some 

 of the Michigan brook lampreys have almost lost these weapons. 



Summary of the Life History of Lampreys: 



1. Lampreys are among the lowest of the fish -like forms and are 

 found in the temperate zones of both hemispheres but are more 

 abundant in the northern than in the southern hemisphere. 



2. There are three, possibly four kinds of lampreys in New York 

 State waters. 



3. The eggs are always laid in fresh water streams, mostly dur- 

 ing the months of April, May and June. 



4. The lampreys spawn but once, soon after which they all die. 



5. There is a young or larval stage corresponding with the tad- 

 pole of the frog and toad, in which the structure and mode of life 

 is quite different from the adult. 



6. The young or larval lampreys, ammocoetes or mud lampreys, 

 live from four to five years in the mud and sand along the streams 

 where the eggs are laid. 



7. When sufficiently mature at the end of four to five years the 

 larval lampreys transform to the adult stage. In this process they 

 acquire new structures which prepare them for their free, parasitic 

 life. 



8. The time required for transformation is from July- August 

 to the latter part of January and extends in some to February 

 and March. During transformation they remain under the sand 

 and gravel for protection. 



9. When transformed, the sea lamprey migrates from the fresh 

 water stream to the ocean. The lake lamprey migrates down the 

 stream to one of the large, fresh-water lakes. In the ocean or the 

 lake the adult lampreys pre}^ upon fish, sucking their blocd. Their 

 parasitic life continues for one and one-half to three and one-half 

 years, then they return to the fresh-water streams to lay their eggs 

 for a new generation. 



10. The brook lamprey grows to its full size in the larval stage. 

 When fully transformed, it does not, like the sea and the lake 

 lamprey, go to the sea or lake to prey upon fish, but proceeds at 

 once to the spawning grounds up the stream where it builds its 

 nest, lays its eggs and then dies. Their free life in the water is 

 then only two or three weeks, perhaps less. 



