146 GIANT FISHES 



of June, then move rapidly up the west coast of Ireland and 

 right round the north of Scotland, where they appear to split 

 up into two main groups, one of which makes for the coast of 

 Norway and the other moves southwards again into the North 

 Sea, getting to about the coast of Yorkshire. The approach 

 of winter, with the consequent fall in the temperature of the 

 sea, sees another migration of Tunnies in the reverse direction, 

 the fish returning to warmer waters to await another gathering 

 for spawning purposes in the following spring. 



It is not certain whether or no there is an interchange 

 between the populations of Tunny in the Atlantic and Mediter- 

 ranean respectively, but this is a question that may be settled 

 when a satisfactory method of marking individual fish has 

 been devised. Another matter of dispute is whether the 

 Tunny actually crosses the Atlantic, or whether the fish found 

 on the American coast form a separate race. The fact that 

 a broken hook found in a fish caught near Sardinia seemed to 

 have been manufactured in America suggests that at least 

 one Tunny has made this stupendous journey. 



The presence of two more or less definite spawning areas 

 has been already mentioned, and further investigation will 

 doubtless reveal others. The eggs of the Common Tunny 

 have now been recognized, but a full series of larval and young 

 stages has still to be discovered and properly described. The 

 eggs are small and buoyant, and the larval fishes, which hatch 

 out in about two days, are less than a quarter of an inch in 

 length. The young fish are said to grow very rapidly, and 

 individuals hatched in June have reached a weight of about 

 12 to 18 ounces by September. They probably become mature 

 during the third year of life, when they have attained to a 

 weight of about 33 lb. It may be noted that small and large 

 fish are rarely, if ever, found in the same shoal, and that the 

 largest fish of all are quite often solitary in their habits. 



Tunnies are food-fishes of importance, and, although the 

 flesh is not often consumed fresh, it is rich in oil and very 

 suitable for canning. In the Mediterranean the Tunny has 

 been of great economic importance for centuries, and, as Dr. 

 Jenkins remarks, " there can be little doubt that it played a 

 part in the food-supply of the Greeks and Romans and other 

 Mediterranean peoples similar to that of the Herring for 



