64 



Appendices to Twenty -fifth Annual Report 



No. 9194 had been previously marked as a 6-lb. kelt on the 

 20th January, when it weighed 6 lbs., so that its long delay in the river 

 was accompanied by a reduction in weight. 



In each of these cases we find that the scale of the clean fish is, in all 

 essential details, a copy of that taken in the kelt stage, with the addition 

 round the periphery of the new growth formed in the sea after marking, 

 and before recapture on the return of the fish to the river. It will be 

 seen from the photographs (Plates IV. and V.) that the junction of the 

 old and new material is distinct and the intervening superficial suture 

 (spawning mark) clearly visible. This is strong evidence that these 

 salmon had not shed their scales between the dates of marking and 

 recapture, which, in the case of the Helmsdale fish (No. 1180), was 

 about 164 months. We may, however, trace the history of this last 

 fish a little further back so as to find out the approximate time it had 

 spent in the river before it was marked, and the lines on its scales 

 denote that after migrating as a two-year-old smolt, it had remained a 

 little more than the same time in the sea and had there begun the 

 feeding of a third summer, which is represented by some six or seven 

 lines, corresponding to what we find in salmon returning in May or 

 June when about 4| to 4| years old. I do not suppose that anyone 

 will allege that there is any shedding and renewal of scales in the river, 

 and it does not seem to be unduly straining the point to say that this 

 salmon had not shed its scales during the period of nearly two years, 

 commencing with its entry to the river in May or June 1904 and 

 terminating on 30th April 1906, when it was killed as a spring fish. 



The intervals between marking and recapture in the cases of two 

 Tay fish (Nos. 7780 and 9194) are much shorter, but these were both 

 kelts that returned in the autumn of the same season. No. 7780 was 

 marked in January 1906 as the kelt of a summer fish that had 

 apparently entered the river in May or June 1906, and, notwithstanding 

 its weight (12| lbs.), the scale shows it was then the same age as the 

 5-lb. Helmsdale kelt (No. 1180), both being 4|-4| years old. While 

 the latter took 16| months to put on 9 lbs., the larger Tay fish gained 

 nearly 11| lbs. in 6| months, and this is the greatest increase any of 

 our Tay recaptures exhibit in such a brief interval. It must be noted, 

 however, that in January 1906 the Tay was comparatively high and its 

 temperature warm, and these conditions were favourable for a rapid 

 journey to the sea. The lines added on the scale indicate that there 

 was little delay in the river, as immediately surrounding the spawning 

 mark they are narrow and close together and resemble the annual ring 

 which seems to occur in early spring, while the later growth is denoted 

 by unusually broad and widely-spaced lines, showing generous feeding. 

 No. 9194 was a grilse kelt, and, unlike other grilse, seemed in no hurry 

 to leave the upper waters. After being marked for the second time it 

 probably made a quick descent, and four months later, when taken in 

 the nets, it weighed 11| lbs. Nos. 9341 and 9342 are instances of 

 grilse kelts returning 14| and 15 months after they were marked, as 

 spring salmon. 



Instead of giving details of the marked fish of which scales were 

 sent to me, I have prepared a diagram showing their life-history 

 as deduced from the scales, and also what we know from the 

 particulars of marking. All the Tay recaptures were made in 

 July and August of either the same' or the following year, with 

 the exception of one made in March, and two made in April, and 

 it is unfortunate that spring fish should be so poorly represented in 

 the list, as it is of importance to find out which class of spawners come 



