FAMILY PETROMYZONIDAE 71 



Minnesota River near Savage, Minnesota, the brook lampreys spawn 

 by the hundreds each year from May 5 to May 20. They congregate 

 in the gravel riffles, where they attach themselves to stones by their 

 suckerlike buccal funnels. Shallow nests are hollowed out and the 

 eggs deposited. Frequentlj^ several males attend one female. 



The larval ammocoetes drift downstream into the pools, where they 

 live buried in the bottom mud. The length of the larval period has 

 been estimated as about five years. Some of the ammocoetes found in 

 the Credit River were larger than the adults. The larval forms are 

 lighter in color than the adults. The dorsal fin of the larval forms is 

 continuous with the caudal fin. The buccal funnel is smaller than 

 that of the adults. 



The adults do not feed and hence are nonparasitic. The adult life is 

 short, for the adults die soon after spawning. Detailed life histories 

 are described by Gage (1893 and 1928) . 



