predation under ice, and against the gamete wastage through hybridization resulting from 

 overlapping spawing times. 



According to Delisle (1969a) ovarian eggs ranged from 0.80 to 0.95 mm in the rainbow 

 smelt but only 0.54 to 0.65 mm in the pygmy smelt. 



Food 



Delisle (1969a) found that the rainbow smelt tended to feed at a higher trophic level; 

 over 50% of its diet in Lake Heney consisted of adult pygmy and young pygmy and rainbow 

 smelts. They also ate invertebrates such as Mysis, copepods and Ephemeroptera. The food of 

 the pygmy smelt on the other hand, was composed largely of plankton, mainly adults and eggs 

 of Daphnia, and adult Cyclops and Bosmina . 



Kendall (1927) reported that small smelt (3-1/32 to 3-7/8 inches = 77-98 mm) dynamited in 

 Wilton Pond in spring contained gnat and caddis fly larvae and small Diptera. In Sebago 

 Lake he found that large smelt were piscivorous (most commonly on smelt). In Lake Utopia, 

 New Brunswick, Bajkov (MS 1936) found pygmy smelt to be planktivorous , feeding mostly on 

 Diaptomus , Cyclops , Leptodora , Daphnia , Epischura , and Bosmina . He found rainbow smelt in 

 the lake fed mostly on small smelt. Rainbow smelt were occasionally caught on artificial 

 flys at the surface. 



Size, Age and Growth 



The maximum total length of pygmy smelt in Lake Heney is less than 125 mm TL, that of 

 rainbow smelt about 300 mm (Delisle, 1969a). Delisle noted that the pygmy grows more 

 slowly, at five years reaching only 120 mm TL and 74 g. The maximum age he gave for the 

 pygmy smelt was 5 years, but only 11% reached 4 years of age and 2%, 5 years; for rainbow 

 smelt the maximum was 6 years with 31% reaching 4 years and 4%, 6 years. The pygmies 

 reached sexual maturity at 2 years while most of the rainbows required 3 years. Copeman 

 (1977) found his spawning samples of pygmy smelt from Heney and Green lakes to consist 

 entirely of 2 year-olds (mean standard length 75.8 mm), while Heney rainbow smelts consisted 

 of 25% 3 year-olds, 65% 4 year-olds, and 10% 5 year-olds ranging from 157-206 mm SL. The 

 large and small smelts in Lake Champlain have not yet been proven identical to the rainbow 

 and pygmy smelts; nevertheless Greene (1930) found in winter angling catches that the small 

 form was composed of 1 to 3 year-olds with mean lengths 121-130 mm SL, and the large form of 

 young-of-the-year to 5 year-olds 131 to 249 mm SL. The small form matured in their second 

 year while only 31% of the two-year-old large smelt were mature. 



These admittedly limited data suggest that, at least when sympatric, pygmy smelt grow 

 more slowly, mature earlier, and have a shorter life span. The results of Copeman and 

 McAllister (1978), Zillox and Youngs (1958), and the Green Lake transplant to the Great 

 Lakes, suggest that under natural conditions, growth rates of a given species are relatively 

 constant within a lake. 



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