MORPHOLOGICAL RESULTS 



The sources, samples sizes, body lengths and other details on smelt samples studied are 

 presented in Table 1. Ranges, means and standard deviations of characters are given for 

 each population of smelt studied in Table 2. Frequency of gill rakers in each population is 

 shown in Fig. 2 and relationship of orbit diameter to standard length in Fig. 3. Fig. 4 

 shows the length frequencies of the spawning pygmy and rainbow smelt samples in Utopia Lake, 

 New Brunswick; other samples, not taken at spawning time, are not shown. 



Principal components one and two are plotted in Fig. 5 and show complete separation of 

 pygmy and rainbow smelts. Latent vectors are shown in Table 3. Latent vectors one and two 

 subsumed 83% of the variance. Principal components 3 to 6 did not aid in separating the 

 pygmy and rainbow smelts. PCA runs with data unlogged but standardized, and with raw data 

 gave substantially similar results in separating the pygmy and rainbow smelts. 



BIOLOGICAL DATA 



Reproduction 



In Lake Heney, Quebec, rainbow smelt spawn before ice break-up in water about 6 m deep 

 and below 4 degrees C, from March 17 to April 12. The pygmy smelt spawn following break-up 

 at an average temperature of 6 degrees C on sand and gravel beaches between April 22 and 

 May 10 (Delisle, 1969a). 



In Green Lake, Maine, rainbow smelt were caught from March 25 to April 20, while pygmy 

 smelt were caught from May 5 to May 20 according to Kendall (1927, p. 296). Copeman (1973) 

 reported there was a period of at least 8 to 16 days between spawning runs of the rainbow 

 and pygmy smelts where spawning did not occur. In Utopia Lake, New Brunswick, our 

 collections of spawning rainbow smelt were taken in Mill Stream at the northeast end of the 

 lake on 7 April 1980 at 4 degrees C, while pygmy smelt were collected in Mill Brook on the 

 northwest shore 12 May 1981. Pygmy smelt sjawn in Mill Stream, at the northeastern end of 

 the lake, in 15 to 60 cm of water; a dam between Lake Utopia and Mill Lake prevents the 

 smelt from entering Mill Lake (Peter Cronin, pers. coram.). Bridges and Delisle (1974) 

 reported pygmy smelt spawning in Lake Utopia 22 May 1972. A population of pygmy smelt 

 transplanted from Utopia Lake to Meach Lake, Gatineau County, Quebec (Dymond, 1939; Delisle 

 and Veilleux, 1969) was spawning on 8 May 1963 (collection NMC71-651) , and 19 May 1971 

 (Bridges and Delisle, 1974). Although the large and small smelt of Sebago Lake, Cumberland 

 County, Maine has not been (yet) shown to correspond to rainbow and pygmy smelts, Kendall 

 (1927) nevertheless reported that the large smelt ran before the small smelt, and often as 

 soon as the ice is out and sometimes before, a sequence which corresponds to the above 

 pattern. 



While over the whole range of the two smelt species there may be an overlap in spawning 

 times, there seems to be a separation in their spawning periods when the two are found in 

 the same lake, and the pygmy species spawns later than the rainbow smelt. There may be a 

 balance struck between selection for the faster development in warmer water, the lower 



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