ABSTRACT 



The pygmy smelt, Osmerus spectrum Cope, 1870, is a valid lacustrine sibling species 

 distinguished from the sympatric rainbow smelt, Osmerus mordax (Mitchill, 1815) by higher 

 gill raker counts, relatively larger eye, lower lateral scale counts, and smaller maximum 

 size. Transplant experiments demonstrate that gill raker and vertebral counts do not change 

 significantly when smelt populations are transplanted to different environments. Spawning 

 times of the pygmy smelt are later and do not overlap with those of the rainbow smelt when 

 the two species are in the same lake. 



The pygmy smelt is a planktivore throughout its life, while the rainbow smelt becomes 

 piscivorous at larger sizes. The pygmy smelt grows more slowly, has a lower longevity, and 

 spawns at a younger age. Pygmy smelt are identified from Heney Lake, Quebec, Utopia Lake, 

 New Brunswick, Green Lake and Wilton Pond in Maine. A topotypic neotype is designated from 

 Wilton Pond and deposited in the National Museum of Natural Sciences, Ottawa. 



Suggestions are made as to the time and place of origin of the pygmy smelt. Management 

 implications of the existence of two species of smelts of different sizes are suggested. 

 These include the value of pygmy smelt as a forage fish and the rainbow smelt as a 

 gamef ish. 



