62 Appendices to Twenty sixth Annual Report 



APPENDIX III. 



THE SCALES OF SALMON. 



By H. W. JOHNSTON. 



In continuation of my two previous papers on the Scales of Salmon,* 

 I am now able to give some further information on the subject, and also 

 two additional photographs of scales of salmon which had been marked 

 as smolts. 



"Wired" Smolts. 



In the Twenty-fifth Report it was related how the smolts marked with a 

 wire by the Tay Salmon Fisheries Company, in or about May 1905, had 

 returned as grilse in 1906 and as small spring salmon early in 1907. 

 After the Report was printed, captures were made of smolts " wired " at 

 the same time, which came back to the river as summer and autumn fish 

 later on in 1907. The evidence shows that all, or nearly all, of these 

 recaptured fish were returning to fresh water for the first time since 

 they migrated as smolts in the early months of 1905; so that, to this 

 extent, we have corroboration of the previous conclusions drawn from 

 scales and enunciated in the Twenty-third Report, where it was stated 

 that the return of the smolt is spread over three years if not more. Since 

 these views were expressed, I have examined the scales of some salmon 

 which do not seem to have limited their marine residence to three years, 

 but evidently prolonged it further, and I am now inclined more con- 

 fidently to state what before I only hinted, viz. — that some smolts 

 remain for four or five years in the sea, and only return to spawn when 

 comparatively old fish. This is specially the case with males, but it 

 must not be supposed that all large fish of either sex have spent the most 

 of their existence in salt water, as we know from the marking records 

 that this is not so ; nevertheless, I do not think there is any doubt that 

 the fresh-water life of some male salmon of considerable age and weight 

 is very limited. 



It is hoped that the Tay Salmon Fisheries Company, by making fur- 

 ther captures of fish marked in 1905, may still be able to add to our 

 information on this point. 



I do not purpose giving in statistical form the numbers of each year's 

 lines on the scales of the " wired " fish recaptured in the summer and 

 autumn of 1907, as they much resemble those previously stated as char- 

 acteristic of salmon of the same age. Before dealing separately with 

 these classes, I may emphasise the value of the Spawning-mark as indi- 

 cating whether a fish has spawned or not, within the previous two or 



* Tiwnty -third Annual Report (Part II., App. II.), and Twenty-fifth Annual Report 

 (Part II., App. II.). 



