50 The Distribution of Parasite- Infected Fish 



These haddocks are generally also infected with trematode cysts in 

 the anterior spinal nerves which are visible on the inside surface of the 

 abdomen {n. Fig. 1). Some of the haddocks caught near Aberdeen have 

 these trematode parasites, an infection which is recorded by Lebour as 

 common. 



The spotted haddock is not known to occur in either the Iceland or 

 Faroe fisheries. The Faroe haddock appears to be on the whole richer 

 in flesh than the .Shetland or North Sea fish, and it does not lose con- 

 dition after spawning, so much, or for so long a period as the fish from 

 the two other re<jions. 



Fig. 3. 



The spotted haddock was, I am informed, unknown in Aberdeen 

 seventeen years ago, and one gentleman who cured haddocks on the 

 west coast of Shetland (Walls, Scalloway) twenty-five years ago did not 

 know them. It is said however, that defective haddocks, possibly 

 spotted, had been sometimes taken twenty-five years ago in June in 

 nets which had sunk to the bottom with weight of herrings, between 

 Ve Skerries and Blue Mull Sound. 



The affected codlings exhibit coiled nematodes scattered singly 

 through the muscles: they are taken at Faroe, Rona and Rockall: 

 especially in the first-mentioned fishing region. At present it is believed 



