INTRODUCTION 



In 1870 Edward Drinker Cope, one of the deans of North American ichthyology, named a new 

 species, Osmerus spectrum , from Wilton Pond, Franklin County, Maine, illustrated in Fig. 1. 

 This species was treated by subsequent workers as a species, a subspecies, and later a full 

 synonym of the rainbow smelt, Osmerus mordax (Mitchill, 1815). But recently, Delisle 

 (1969a) and Copeman (1977) discovered morphologically separable sympatric populations, one 

 large-sized, one small, In Lake Heney, Quebec and Green Lake, Maine. Based on the solid 

 foundations laid by these two workers and our own findings, we re-establish the smaller form 

 as a valid species, for which the name Osmerus spectrum Cope, 1870 is available. This paper 

 discusses the taxonomy of Osmerus spectrum , the stability of its characters when 

 transplanted, its biology, distribution and origin. The management implications of the 

 existence of two species of smelt are outlined. 



Authors have discussed the two forms of smelts under a variety of common names, large 

 smelt and small smelt, large and small races of smelt, dwarf and giant smelt, pygmy and 

 normal smelt. To keep our discussions clear we will generally reserve the name pygmy smelt 

 for populations that we identify as Osmerus spectrum Cope, 1870, and rainbow smelt for 

 populations that we identify as Osmerus mordax (Mitchill, 1815). Where populations, which 

 we have not examined and identified, differ in size, we will refer to them as small and 

 large smelt. 



HISTORY 



Cope (1870) described Osmerus spectrum from two specimens collected in Wilton Pond near 

 the head of the southwest branch of the Kennebec River in southwestern Maine. According to 

 Kendall (1914) Wilton Pond is also known as Wilson Pond and is tributary to the Sandy River. 

 Cope described a "medium-size" specimen as 3 in. 6 lin. (=3.5 inches = 89 mm, probably 

 standard length). He further stated that "The characteristics of this species, according to 

 Commissioner Atkins, are seen in specimens of larger size than those herein described, which 

 were taken in breeding condition." Kendall (1927) later recorded specimens of breeding 

 smelt 2-1/2 to 3-9/16 inches (57-80 mm SL) and one specimen 5-7/8 inches (about 133 mm SL) 

 from Wilton Pond. Our own specimens from the Pond measure 72.6 to 100.8 mm in standard 

 length (SL). 



The type specimens of Osmerus spectrum apparently no longer exist. The late Dr. James A. 

 Bbhlke, (in lit . , 17 July 1979) reported that he had checked the Philadelphia Academy of 

 Natural Sciences type collection, general collection and type file without success. Nor did 

 H.W. Fowler's (1912) list of salmonoids in the Academy contain reference to the smelt types. 

 Dr. Bbhlke further reported that many of Cope's types disintegrated or disappeared before 

 reaching the Academy. Dr. Labbish N. Chao was unable to find the types In the Smithsonian 

 Institute, Washington. It therefore appears that Cope's types of Osmerus spectrum are no 

 longer in existence. 



Cope (1870) followed the description of Osmerus spectrum , on the same page, with the 

 description of another new species, Osmerus abbottii Cope, described from Cobessicontic 



