CHAPTER XI 

 THE COD FAMILY 



Before comparing the brain pattern of the different species 

 of Gadoids it may be well to make a few general remarks about this 

 family. As Cunningham has pointed out, like the flat-fish, all 

 the members of this family are without spiny fin-rays and generally 

 without spines or bony armour ; they carry no weapons of offence 

 or defence except their powerful Jaws and teeth. Some, like the 

 cod, are powerful swimmers and the form of their body makes for 

 speed which has given rise to the fishermen's saying " a cod's head 

 and a mackerel tail," in describing the best lines for a fast vessel. 



The fin rays are soft and flexible and the scales are small, smooth, 

 and thin and easily detachable. The dorsal and ventral fins extend 

 a great part of the length of the body, the tail fin is separate. The 

 eyes are large, except in the nocturnal feeders and in many kinds 

 there are barbels on the lips and chin. The majority feed in the 

 day time, hunting their prey by sight, and being voracious and 

 rapacious fish have large mouths. Some, besides a fish diet, feed 

 on Crustacea and mollusca so that there is a great variety in dentition 

 but all have powerful pharyngeal teeth. 



The following is a classification after Cmmingham of British 

 species ; but we include only those fish which have been studied in 

 relation to their brain pattern. 



I. Species with three dorsal fins and two ventral fins : 



i. The cod. — Grows to a large size ; body not much elongated ; 

 colour greenish-yellow with numerous small black spots, 

 lateral line, white, and there is a barbel on the chin, 

 ii. The haddock. — Smaller, but similar, has a black blotch on 



the shoulder and a black lateral line. Barbel small. 

 ill. The ivhiting. — Sides silvery, no barbel ; body more slender 

 and better fitted for active motion as seeking their prey in 

 higher regions than do the two preceding, 

 iv. The coal-fish. — Differs from the preceding in having a 

 lower jaw longer than the upper. It has a small barbel. 

 Colour dark slate blue, almost black on sides ; lateral fine 

 white. 



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