130 SALT-WATER FISHES 



Scombridae 



The Mackerel 



The Mackerel {Scomber scomber) is the type of all these 

 fishes, commercially the most important, and certainly the 

 most beautiful. It is a familiar fish enough, blue, with very 

 small scales and irregular black bands down its sides, the 

 latter, as well as the under surface, showing a beautiful pink 

 metallic sheen and silver reflections. The colouring of the 

 mackerel is subject to much variation, and while some races 

 have spots and scribbled lines between the bars, or in their 

 place, there are individuals (see 'The Zoologist, July, 1897) 

 with neither spots nor bands nor markings of any kind, but 

 of uniform blue or green. There is a small keel on each lobe 

 of the tail, and there are five or six finlets behind the second 

 dorsal fin, the first dorsal having from eleven to fourteen 

 spines. The mouth is well provided with small, sharp teeth, 

 which cover both jaws, as well as the tongue and palate. 



Few of our sea fish are, in fact, of greater importance than 

 the beautiful mackerel, for which there are distinct and regular 

 hook and net fisheries, according to the season. The cod 

 and herring may occupy the greater fleets of the North Sea ; 

 the pilchard has its restricted area in the south-west ; but the 

 great mackerel fisheries of the coasts of Britain and Ireland 

 are of immense annual value. 



Although we recognise but two species of Scomber, it is 

 evident to all who have seen even the common species in 

 different seas and markets that there are several types or 

 races. To the unscientific observer size and the presence or 

 absence of spots will be the determining character ; but the 

 biologist takes closer account of the number of fin-rays and 

 transverse bars, and on this basis Mr. Garstang recently con- 

 ducted a very interesting investigation of these racial pecu- 

 liarities. The results of his enquiry have been ably summarised 

 in the journal of the Marine Biological Association (November, 



