hybridization at the population level, but upwards of 70 markers are required to 

 discriminate between pure individuals, if they exist, and backcrossed individuals in 

 hybrid swarms (Boecklen and Howard 1997). 



The distribution of non-native markers may not be randomly distributed among the fish 

 in a sample primarily because hybridization has only recently begun in the population, 

 the sample contains individuals from two or more genetically divergent populations, or 

 both. Such collections can be analyzed at the individual level only. Since such samples 

 do not come from hybrid swarms, the proportion of native and non-native markers cannot 

 reliably be estimated. In these cases, the sample may contain some non-hybridized 

 individuals. Rather than reporting percent genetic contributions we report the number of 

 individuals in the sample, based on the fragments they possessed that may be non- 

 hybridized. 



Literature Cited: 



Boecklen WJ, and Howard DJ (1997) Genetic analysis of hybrid zones: numbers of 

 markers and power of resolution. Ecolog}' 78 (8) pp. 261 1-2616. 



Sample Details : 



Blackfoot River Telemetry 2002: The original letter that we received regarding these 

 samples indicated that there were going to be twenty- five sent to us, but we only received 

 fifteen. All fifteen successfully amplified individuals in this sample displayed PfNE 

 fragments diagnostic of westslope cutthroat trout. 



• Three of these individuals only displayed PINE fragments diagnostic of 

 westslope cutthroat trout. 



o Individual U: 8, 9, 1 1 



• Twelve individuals also displayed PINE fragments diagnostic of rainbow 

 trout. 



o Eleven of these individuals appear to be post first generation 



hybrids. Individual #: 1, 2, 3, 4, 5, 6, 7, 10, 12, 13, 15 

 o Individual 14 appears to be a first generation hybrid. 



Due to the random reshuffling of alleles during sexual reproduction and the limited 

 number of diagnostic markers we use, we cannot be sure that the individuals displaying 

 only westslope cutthroat PINE fragments did not come from a hybrid population or that 

 they are truly "pure." As a main stem sample, this analysis does not represent a single 

 population, and further analysis is not possible. 



The original letter also asked us to provide hybridization information for each individual 

 fish, labeled with a four-digit code that corresponded to a transmitter number. The 

 samples we received were only labeled with a two-digit code that we kept through out the 

 analysis. 



Deep Creek: All twenty-four successfully amplified individuals in this sample displayed 

 PINE fragments diagnostic of Westslope cutthroat trout. Six individuals also displayed 

 PENE fragments diagnostic of rainbow trout. With a sample size of twenty- four, we have 



