t5 



prominent parr marks silvery-gray in color; white tips on anal 

 and ventra] fins. 



2. Spetting. - Large spots, few in number, concentrated in 

 caudal area, few below lateral line; none or very few on body 

 anterior to dorsal fin; dorsa] and caudal fin heavily spotted. 



The "Surprise Lake" golden trout tended to have the follow- 

 ing characteristics: 



1. Coloration - Silvery or lighter pigmented; less vivid 

 olive-green back; anal fin with less orange coloration; rosy 

 lateral band often less vivid than on "typical" type; 10-12 

 large, silvery-gray parr marks which do not stand out as much as 

 on the "typical"; white tips on anal and ventral fins. 



2. Spotting - Same as on "typical" golden trout except for 

 more spotting anterior to dorsal fin. 



3. Body - Usually more robust, less slender than "typical" 

 golden trout. 



To complicate further, there were variations in colorations 

 of some individual golden trout in specific waters. Similar to 

 California habitats (Pister, pers. comm.) some individuals in the 

 "typical" class became more silvery and somewhat similar to the 

 "Surprise Lake" fish, especially in large lakes. Lighter color 

 variations were usually females scrutinized well after the spawn- 

 ing season. Large lakes also had large males and females without 

 prominent parr markings. Often ]arge males in large lakes were 

 crimson frorr. the eye to the anal fin with this vivid color 

 merging into the olive-green colored back. The newest State of 

 Montana record (1981) was a male with this dominant red colora- 

 tion. 



Age and Growth 



The most pronounced differences in growth between popula- 

 tions of golden trout were among Age IV and older fish (Table 4). 

 A mean difference of 4.8, 4.3 and 3.9 inches existed for the Ages 

 IV, V and VII fish, respectively. The smallest golden trout 

 resided in the small pond-like lakes in the Hidden Lake chain #5, 

 6 and 7. Golden Trout Lake also contained snail fish. Island 

 Lake appeared overpopulated with somewhat stunted fish. The 

 population structure in Island Lake appeared similar to that of 

 Cottonwood Lake #3 in California (Curtis 1934). 



Sylvan and Little Lightning lakes are not noted for large 

 fish; however, populations were usually rejn esented with a 

 complement of age groups. Growth inhibition in Sylvan Lake 

 appeared food related, while Little Lightning Lake acted as a 

 nursery for Lightning Lake with some older residents. Ninety- 

 five percent of the fish were 3 years old and younger. Growth 

 rates in Cottonwood Lake #4 in California resemble that in Sylvan 

 Lake. 



- 17 - 



