48 



Appendices to Fourth Anmual Report 



when they enter the loch, some that I tasted being quite insipid. They 

 have little commercial value, and sell for a few shillings a cran. 



Growth of the Herring. 



The herring improve rapidly in condition from the moment they enter 

 Loch Fyne. They feed ravenously on the immense shoals of copepods 

 which make their appearance in May. The commonest form is Galanus 

 jinmarchiciLS, a species which is common around the British Isles, but 

 which in Loch Fyne constitutes almost the sole food of the herring at this 

 season. This species appears to occur in Loch Fyne throughout the year, 

 but is rare in the colder months. From January to March a few may be 

 taken any calm day with the surface net. They are then quite trans- 

 parent, and the arrangement of the viscera is easily seen through the 

 carapace. In April they rapidly increase in number, and a few are seen 

 to have a number of small reddish oil globules under the carapace. In 

 May and June they occur in myriads. At this time immense floating 

 masses are to be seen in calm weather, which give the sea quite a red tint. 

 The copepod itself is really transparent. The colour is due to the large 

 number of red oil globules above mentioned. One day in the month of 

 June the tide left such immense numbers of this copepod on the beach in 

 front of the Tarbert Laboratory that the ripples in the sand appeared to 

 be filled with blood. In July the number of Calani decreases rapidly, and 

 in iiugust we again found transparent specimens, while in September the 

 stock was reduced to that found in the beginning of the year. Whether 

 the myriads of Calani are bred in Loch Fyne or enter it in the spring I 

 have not determined. It is, however, a significant fact that the herring 

 enter Loch Fyne as the crustacean becomes abundant, and begin to leave 

 it again as the stock gets exhausted. There is no doubt that the move- 

 ments of the herring are to a large extent dependent on those of the 

 copepods on w^hich they feed. This fact is well-known to the fishermen. 

 The floating masses are easily affected by wind and tide, and according 

 to the direction of the wind, the copepods (and therefore the herring) may 

 be expected in certain quarters. This is, however, not an infallible guide, 

 but it serves as a basis to work upon. 



It has already been stated that the fish thrive well on such rich and 

 abundant food. In the beginning of the season the herring average 10 

 inches in length; three months afterwards the average is 12 inches, and 

 I have seen herring in August quite 15 inches long. There are evidently 

 several broods or races of herring in Loch Fyne during the summer. In 

 May the fish do not vary much from 10 inches in length, and the roe and 

 milt is not developed. During the next two months two broods at any 

 rate may be distinguished. The one does not increase much in length, 

 but quickly improves in condition, and the roe and milt advance rapidly 

 towards maturity. At the end of July the ova are nearly ripe, and the 

 fish are short and thick compared with others. These spawn in August. 

 The second brood is not distinguishable from the first in the early part of 

 the season. As time goes on, however, these fish increase from 2 to 3 

 inches in length, and in August are immense fish, the finest I ever saw. 

 During the period of rapid growth the development of the reproductive 

 elements remains comparatively in abeyance. They are not ripe until the 

 middle of September at the earliest, while the majority sj:)awn in October. 



I believe there are other races of herring in Loch Fyne besides the 

 two named, but the subject is a difficult one and requires further study. 

 I am, therefore, led to think that Loch Fyne is now a feeding area for 

 the herring of the Ballantrae, Campbeltown, and other districts, and that 

 the whole collection is a mixed one. As the copepods diminish in 



