• 7 — REPORT ON THE MACKEREL 



the tail, however light they may be, do not form a good plan of marking a fish, which 

 is a specially swift swimmer; and as it will be necessary to extend these marking experi- 

 ments on a larger scale and to many different localities, I wish to propose another form, 

 which is more likely to give good results. — By way of a joke, the fishermen in different 

 regions of the world sometimes put narrow rubber rings round the head of mackerel and 

 set them free with this adornment, which is usually fixed just before or behind the pectoral 

 fins. Such "banded mackerel" have been often recaught, on the shores of France as well 

 as in Great Britain, in Sweden, in Germany and even in the United States! The fish 

 seem to support these rings pretty well, and the rings keep easily in position. This seems 

 to indicate a convenient form of mark, and I think, it would only be necessary to fix a 

 cipher on it and place this label on the back of the animal, so that it may be easily 

 detected. 



Concerning the American mackerel, it may be useful to state, that its habits 

 differ in certain points from those of the European iorm, in consequence of the fact, that 

 both represent different races; but nevertheless there are also many similarities, and 

 especially the wandering movements and the occasional sojourns near the bottom will 

 certainly be recognized to be nearly the same in both forms. The same habit has also 

 been demonstrated to be followed by the mackerel of the Mediterranean, and even more 

 remote and specifically different forms as, for instance, the mackerel of Japan are known 

 to behave in the same way. It is worth mentioning, that the American mackerel in a 

 higher degree than its European relative moves in spring-time near the surface, under 

 circumstances, which allow the fishshoals to be seen and caught with the purse-seine, and 

 in former times by hook, which is well known to be impossible in the Irish spring fishery, 

 as the fish move at a considerable depth below the surface, where they are got by chance, 

 by means of gill-nets. The allurement of the fish by spreading chopped bait in the water, 

 is also a peculiarity of the American mackerel fishery, which proved to be ineffective in 

 the North European waters, especially in the time before spawning. On the other hand, 

 it cannot be doubted, that the American mackerel in early spring come from the deep 

 water, and in late autumn tend to go back there, just as the European fish do. Certain 

 predatory bottom fish have been found with mackerel in their stomachs, and occasionally 

 also some mackerel have been taken immediately at the bottom. The American experts, 

 especially Brown Goode, are of the opinion, that the mackerel do not cross the Gulf 

 Stream eastward, and I think this is perfectly right. It should be possible therefore, to 

 catch the mackerel at a moderate distance from the coast at the bottom in those parts 

 of the year, when the fish are not met with near the surface. Experiments to catch the 

 mackerel in this way and marking experiments, that will enable us to follow the general 

 movements of these fish, will certainly prove useful in the direction of increasing our 

 knowledge of the biology of the mackerel in American waters. 



It is obvious then, that we must to a certain degree come back to the theory of 

 earlier writers, that the mackerel perform extensive migrations from and to deeper waters, 

 where they indulge in a kind of winter -rest. It is not necessary however to revive 

 the old opinion, that during this time of rest the fish become blind and are hidden in the 

 mud. The mackerel are at no time of their life blind, but we are entitled to speak of a 

 resting time, as the fish abstain from taking food for 2 or 3 months in the beginning of 

 the winter, from November on to January. In the following period, though keeping still 



