312 MARKETABLE BRITISH MARINE FISHES 



1. The Mackerel. — Air-bladder absent, no sign of a 

 corselet. 



2. The Spanish Mackerel. — Air-bladder present, a rudi- 

 mentary corselet of somewhat enlarged scales below the 

 pectoral fin ; eye larger than in the common mackerel. 



II. Species of small size with two dorsal fins widely sepa- 

 rated ; a corselet on the breast region ; and a keel in the middle of 

 the side of the root of the tail. 



3. The Plain Bonito. 



III. Species of large size in which the first dorsal reaches to 

 the beginning of the second ; the corselet very distinct, and the 

 central keel on the root of the tail well developed. 



4. The Short-finned or Common Tunny. — Corselet 

 distinct ; breast-fin not reaching back to the commence- 

 ment of the second dorsal. 



5. The Long-finned Tunny or Germon. — Corselet obs- 

 cure ; breast-fin reaching behind the end of the second 

 dorsal. 



6. The Bonito. — Breast-fin quite short ; corselet larger than 

 in either of the previous two ; four or five long curved 

 blue stripes passing along the sides and belly, bending 

 upwards behind. 



7. The Pelamid or Belted Bonito. — Corselet much 

 smaller than in the last ; broad bands passing straight 

 down from the back, narrow bands slanting across them 

 downwards and forwards. 



The Spanish mackerel is commoner in the south, i.e. in the 

 Mediterranean and at Madeira than on the British coasts, and as 

 no practical importance belongs to its history or that of the 

 tunnies in this country, only the common mackerel will be here 

 considered separately. The Remora or sucking fish is placed in 

 the family but has seldom been taken in British seas. 



The Mackerel {Scomber scomber). 



Distinguishing Characters. — Eleven to fourteen spines in the 

 first dorsal fin, which commences a little behind the breast fin. 



