THE MACKEREL OR TUNNY FAMILY 



315 



I examined were taken in anchovy nets in November, 1891, 

 between the Sound and the Eddystone. These were 6 inches to 

 8"3 inches long, and I consider them all to be too large to be 

 derived from the previous spawning, and to be therefore in their 

 second year. They weighed from less than an ounce to over two 

 ounces. A few specimens taken in June on whiffing lines 

 measured 87 to 9'3 inches, and these also might be a year old. 



The smallest ripe specimens I have examined were i r6 to 

 I2'9 inches long, weighing 7} to 9 ounces, the large ripe specimens 

 being 16 or 17 inches long. We may consider the smaller 

 specimens to be two years old, and the others older. 



The young fish do not seem to enter bays or estuaries 

 commonly in large numbers, although I found a few yearling 

 mackerel in the produce of the ground seine in the Hamoaze 

 in September. The j-oung of the year, about 3 inches long, have 



Fig. 143. — Larva of the Mackerel, four days old, alive and magnified. 



been observed by Mr. Dunn at Mevagissey, in August and Sep- 

 tember, but I have never seen or heard of any of that size in 

 Plymouth Sound. At present I am inclined to think that the 

 young in their first half-year remain for the most part out in 

 the open sea. 



Migrations. — At Plymouth there is no month in the year in 

 which mackerel are not taken, but they are scarcest in December 

 and January. This is presumably the time when the fish are 

 farthest from the coast, feeding in the more distant water where 

 the temperature is higher. The few caught in those months in 

 1889-90 were taken 15 to 40 miles south of Plymouth. In 

 February they become more abundant, the largest catches being 

 4,000 to 5,000, the fish still a long way off, 20 to 30 miles from 

 Start Point. In March and April the fish are still a long way 

 off, ^ at least 30 miles from the Sound in March, 20 miles in 



