74 



Appendices to Twenty-fourth Annual Report 



In Xovember the numbers had increased, and many of the young fish 

 showed silvery scales, which, although not quite so bright as those 

 upon migrating smol ts in the spring, nevertheless gave strong presump- 

 tive evidence that these fishes were migrating to the sea. Twenty-nine 

 salmon parr and smolts were caught in fourteen shots with the net at 

 three neighbouring fishing stations. 



In December these silvery fishes were not found, but a limited number 

 of ordinary parr were caught. Three were taken in six casts of the net. 



In January 1906 the fishing showed results similar to those obtained 

 in December. Only 2 salmon parr were found in ten casts of the net, 

 and the parr were without silvery scales and were small in size. Such 

 small parr might be found at any season in this locality. Our nettings 

 in the spring produced very many of them which had probably descended, 

 in company with the migrating smolts, but which were not in a condition 

 to migrate, many of them being only about two inches long. 



In February similar results were obtained. Of 7 parr, 3 were slightly 

 silvery, 1 was a non-silvery parr, and 3 were small fry with scales little 

 more than formed. 



In March fifteen shots with the net resulted in 50 parr and semi- 

 silvery smolts, many about 5| inches long, and, as it were, approximating 

 to the condition of the usual spring smolt. 



.It is more than probable, therefore, I think, that ordinary salmon parr 

 inhabit the upper tidal waters of the Tay at all times. I may add that 

 similarly I have specimens 3 to 3| inches long taken from the stomach 

 of a cormorant which was shot while diligently feeding in tidal water at 

 the mouth of the river Helmsdale; 16 small salmon parr were in the 

 stomach, and the bird was shot in the month of December. We have, 

 however, no evidence to show that these small parr actually enter the sea, 

 as the fry of Pacific coast salmon are reported to do. In the same way I 

 am inclined strongly to doubt if the 8 per cent, of one-year-old parr which 

 were said, on the authority of the Stormontfield experiments, to migrate 

 to the sea, did more than descend to the upper estuary to remain there, 

 as we find that apparently so many parr do through the summer. I 

 am inclined also to think that the parr caught by Dahl in Norway 

 at the mouths of rivers in July and August and which, if I mistake 

 not, he considers are migratory year old fish, are prototypes of the 

 small class of parr found near Kinfauns at all seasons of the year. If 

 one might venture upon a theory from the result of these experiments 

 in the Tay, I would suggest that in all probability the semi-silvery 

 smolt-like specimens we find in November, and which, as I have 

 said, are probably descending to the sea, represent the juvenile 

 company, this 8 per cent., which descended so far with their associates 

 of an older generation, and which after spending the summer in those 

 upper tidal waters make an early descent in winter. In support of this 

 it is worthy of notice that the sizes of the silvery November fish are 

 rather less than the sizes of the twenty-six months old spring smolts 

 and that the silvery migratory dress is less bright. From artificial 

 rearing of young salmon it is abundantly clear that young fish of similar 

 age may be of very different length ; but it is fairly certain that this 

 feature is greatly exaggerated by artificial and abundant feeding in 

 confinement. The view, however, that the November smolts are 

 descending before rather than after the usual time is greatly strength- 

 ened by the examination of the scales. Mr. Johnston, who has 

 examined the scales, describes the fish as " rising two years." If my 

 view is correct, the November migratory smolts will be about twenty 

 months old. The netting in December, January, and February, while 

 showing ordinary parr in this upper tidal area, does not result in 

 evidence to indicate that during these months smolts are descending. 



