THE MACKEREL FAMILY. 355 



movements, from deep to shallow water, and vice versd, 

 the deeper water being affected in winter ; but as the fish 

 is found in any quantity on parts of the east coast at cer- 

 tain seasons only, there is still good reason, for all that has 

 been said to the contrary, to suspect an extensive migra- 

 tional movement along shore. In Bournemouth Bay, for 

 instance, where the fishery is somewhat irregular, mackerel 

 are taken only between the middle of June and the end of 

 October. The spawning-time appears to be late in June ; 

 anyhow, I have found the males with milt early in that 

 month, but they were spent by the beginning of August. 

 The mackerel which are caught during June and the first 

 days of July are rarely over a pound in weight, but the 

 larger " hook " mackerel of August weigh three times as 

 much. They are very powerful swimmers, and their first 

 instinct on being hooked is to sheer wildly to right and 

 left in the endeavour to shake out the hook. I have often 

 known them, indeed, to fray the gut against the keel of 

 the boat. The food of the mackerel consists largely of the 

 fry of herring and other fishes, also of medusae, small crus- 

 taceans, and the like. In the early summer it pursues the 

 fry in large shoals close to the surface, at which time the 

 fishermen catch it in drift-nets or on baits trailed at the 

 surface ; but later in the year, about August as a rule, the 

 shoals break up and the mackerel go to the bottom, when 

 they are caught in the trawl and on ground-lines. The 

 fishermen have an idea that these fish are blind towards 

 the end of winter, being in fact unable to perceive the bait ; 

 but Cunningham 1 offers an explanation of this in their 

 probable absence at that season from the inshore grounds 

 where such hand -lining is practised. The blindness is 

 supposed to be the result of sickness, a fatty film covering 

 the eye. 



The darker, heavier Coly Mackerel can only be regarded 

 as a wanderer from the Mediterranean to our southern 

 1 Marketable Marine Fishes, p. 316. 



